No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
The effects of structure and its dynamics on the ecology and conservation of arthropods in British grasslands
Abstract
The importance of structure in grasslands to arthropods is emphasised. Community dynamics below ground are briefly described. The characteristics of stenophagous, polyphagous, predacious and parasitoid arthropods in relation to structure are outlined. Tall grassland supports more species, individuals and a greater diversity of arthropods than short swards, but some species are characteristic of the latter. The classification of structure in grassland is briefly reviewed. Change in grassland structure occurs through the opposing forces of succession and, in most cases, management. The commonest method of management is grazing, which is characterised by selectivity in the foliage eaten, treading of the sward and deposition of dung. Cutting is sudden, but its effects of defoliation are similar to those of grazing. Burning is considered in less detail. Ploughing, rotovating, re-seeding, fertiliser application, translocation and set-aside are generally forms of agricultural or ‘creative’ management. Human treading can have severe effects on invertebrate diversity and abundance. Management interacts with other factors, such as seasonality, timing, topography, site-specific characteristics and connectivity to produce varied effects on arthropods. The various types of management systems, reclamation, maintenance, agricultural, rotational and others are discussed in relation to management plans and objectives in conservation. It is concluded that conservationists need to be more aware of grassland dynamics, that management by reference to past land-use must be tempered by full consideration of ecological factors and conservation aims and that ‘practical’ and ‘theoretical’ conservationists need to interact more effectively.
... The decline of farmland arthropods has been related to direct effects of intensive agricultural practices at the field and landscape levels and indirect effects related to the simplification of plant communities associated with farmland intensification (Morris, 2000;Woodcock et al., 2013). Intensive management implies the use of agrochemicals such as pesticides and fertilizers. ...
... According to their conclusions, this effect is not only due to the direct mortality associated with harvest, but also to the low habitat suitability for these taxa of mown areas. This effect can be compensated by sowing improved crops that ensure green food resources for arthropods ( Fig. 2; Morris, 2000;Littlewood et al., 2012). ...
... These effects have positive impacts for upper trophic levels. In fact, under an extensive management arthropods and vertebrates increased (Morris, 2000;Stein-Bachinger & Fuchs, 2012;Woodcock et al., 2013). Although generalizations should be made with caution, our review highlights that the implementation of AES on alfalfa crops could benefit endangered species such as the little bustard or Montagu's harrier but only if harvest operations take breeding periods into account, and management of tilling is also organized spatially so that the availability of prey (insects or voles) is optimized. ...
The agriculture intensification required to provide enough food commodities for humans has negative impacts on the environment. To reduce these drawbacks Agri-Environmental Schemes (AES) have been implemented in Europe since the last decade of the twentieth century. One of the measures included in these schemes was the introduction of alfalfas in crop rotation systems. In order to evaluate their suitability as an AES, we synthesize knowledge on the agronomical benefits of alfalfa cultivations, as well as on the relationships of alfalfa crops with biodiversity at three taxonomic levels: vascular plants, arthropods, and vertebrates. Based on the articles reviewed, alfalfas can help restoring native grassland communities due to the nutrient enrichment they provide. Moreover, this legume crop usually ensures food resources not only for invertebrates, but also for vertebrates. Alfalfas tend to harbour a stable arthropod community that benefits surrounding crops by improving ecological processes (pollination, pest predation) and reducing the need to use agrochemicals. At the same time, arthropod abundance attracts vertebrates, especially birds, which supports the role of alfalfa as a conservation tool to favour endangered farmland birds. Additionally, alfalfa crops may function as a reservoir habitat for voles, which are a preferred food resource for farmland-foraging raptors, many of them endangered. On the other hand, birds nesting in alfalfa crops may suffer higher nest destruction rates due to frequent cuts, and voles using alfalfa crops as reservoir may also create agricultural damage in surrounding crops in certain cases. The review also highlights those negative ecological relationships of alfalfa crops with biodiversity can be minimized, and positive effects may also be maximized under the appropriate management of this crop. Examples of such management actions include cut delays or higher cuts to avoid nest destruction, the use of grazing cattle to reduce the impacts of rodent pests, or reduced frequency of cutting or maintaining unharvested strips in the field to maximize positive effects on predatory arthropods and vole availability to raptors. We conclude that alfalfa crops can be considered globally beneficial for farmland biodiversity and a useful management tool for conservation in agricultural landscapes, for example as an AES, and that management should be adapted to particular taxonomical or functional groups.
... The effects induced by changes in land use on arthropods, and more particularly on beetles, are well known for calcareous grasslands (Morris & Rispin 1988;Eyre et al. 1990;Morris 2000;Woodcock et al. 2005). These studies emphasize the importance of vegetation structure, defined as the interplay between succession and management, in maintaining beetle diversity. ...
... In some cases, the floral and faunal quality of degraded grasslands can be improved by suppressing the causes of degradation or re-introducing traditional disturbance regimes, such as mowing (Moog et al. 2002) or grazing Fischer et al. 1996;Moog et al. 2002;Poschlod & WallisDeVries 2002). The traditional land use of sheep grazing is the most current management for conserving dry grasslands (Gibson et al. 1987;Morris 2000) and is currently associated with high biological diversity in semi-natural ecosystems (Tscharntke & Greiler 1995;Wettstein & Schimd 1999). However, when disturbance has been too intense, this method appears to be insufficient to recreate the original ecosystem, in which case ecological restoration can be used (Jackson 1995), as for our study site (Buisson 2006). ...
... The higher production of seeds in ungrazed plots can also explain this general trend; seeds are an attractive food source for insects (Fadda et al. 2007). These parameters contributed to form a habitat complexity which usually offers a greater range of resources available for different beetle species (Morris 2000). ...
Les objectifs principaux de cette thèse sont de quantifier les modifications
engendrées sur les communautés de Coléoptères terricoles d'un écosystème steppique
(la plaine de Crau dans les Bouches-du-Rhône) par des changements d'usage des terres :
une ancienne mise en culture, correspondant à une perturbation exogène, et l'abandon
d'un pâturage ovin séculaire, correspondant à l'arrêt d'un régime de perturbation
endogène.
... However, the greatest difference in the time span since the last mowing event was between these two treatments, highlighting that habitat selection was likely driven by changing vegetation structures. Beetles react differently to mowing, among others, depending on their feeding strategy, and ground-dwelling carabids are, in general, relatively robust against mowing (Morris andRispin 1987, 1988). The negative effects of mowing are more severe in the long term and tend to even turn around on longer time scales (Lafage and Pétillon 2014). ...
... For example, creating microhabitats with low vegetation height supports species adapted to open areas. Meanwhile, species that rely on taller vegetation for shelter, hunting, reproduction, or overwintering can seek refuge in these structures (Morris 2000). Dike management will, therefore, be sitedependent and may not be appropriate for all species in all situations, particularly for rare or threatened ones, and differences in short-and long-term effects of mowing should be considered (Nickel and Hildebrandt 2003). ...
Species-rich grasslands and their associated arthropods have become rare across Europe. Linear green infrastructure, such as river dikes, can serve as secondary habitats and improve the connectivity among isolated grasslands. Although applied extensively on dike grasslands, mowing impairs local arthropod populations, depending on the date and the techniques applied, while leaving areas uncut over winter can support arthropods. To investigate the short-term effects of different mowing dates, hay handling techniques, and overwintering strips on arthropod abundance, species richness, and community composition, we conducted mowing experiments at eleven sites on dikes of River Inn (South Germany). We sampled carabids, spiders, true hoppers, and true bugs, and investigated combinations of mowing dates (June – ‘early’; September – ‘late’) and hay handling techniques (raking or suction), and the effects of overwintering strips located in the middle or upper part of the dikes. Carabids were favored by late mowing and hay suction. Spider species richness profited from overwintering strips in July and showed an overall seasonal decline. True hoppers benefited from early mowing, and true bugs were insensitive to the treatments. Abundance and/or richness of all groups were favored by overwintering strips. The arthropod communities changed across the season, and the mowing dates significantly drove their assemblages. An indicator analysis revealed a non-random distribution of species among treatments. Our results indicate that there is no optimal mowing date for all studied taxa. We conclude that a spatio-temporal mosaic of mowing treatments helps to meet the needs of different arthropods in dike grasslands, and that rotational management promotes arthropod diversity.
... This result was quite expected because the occurrence of a species within a specific microhabitat is intimately linked to the hunting method practiced by the foraging guild it belongs to (Barriga et al. 2010;Diehl et al. 2013;Gibson et al. 1992;Rao 2017). As a result, different hunting guilds need different microhabitat structures (Bell et al. 2001;Morris 2000;Uetz 1979Uetz , 1991. The vertical structure of herbaceous vegetation can vary drastically among grasslands, depending in particular on the management regime (Bell et al. 2001;Chollet et al. 2018). ...
... Nevertheless, the presence of high herbaceous vegetation does not rule out the maintenance of a surface structure suitable for the establishment of wandering species (Maelfait and De Keer 1990;Uetz et al. 1999). In addition, high vegetation should provide increased potential for niche differentiation through the diversification of phytophagous prey (Morris 2000;Woodcock et al. 2009) and indirectly favour the co-occurrence of diverse hunting guilds (Lyons et al. 2018), which could explain the observed enhanced functional diversity. ...
Urbanisation is an ongoing process associated with multiple environmental changes affecting ecosystems worldwide. Temperature and habitat are main drivers of animal communities within cities, but quantifying their relative weights remains a challenge, as urban heat islands (UHI) often co-vary with land-cover. This study aims to disentangle the effects and relevant scale of temperature and habitat on ground-dwelling spider communities. Based on an original sampling design, we collected 20,761 spider individuals belonging to 137 species at 36 sampling sites in the city of Rennes (northwest France). We characterised communities by assessing the number of trapped individuals at each site, as well as calculating several metrics to estimate taxonomic and functional diversities. Temperature metrics were obtained from two sensor networks monitoring UHI (100-m resolution) and near-ground temperature (1-m resolution) independently. Land-cover and isolation were used to describe landscapes, and vegetation structure to describe local habitats. We used generalized linear mixed models to disentangle the effects of temperature from those of habitat at the landscape and local scales, and identified relationships between community descriptors and predictors. We show that temperature-related metrics are important predictors of spider communities, and that the landscape and local scales have independent effects. Near-ground temperature alone explained 24% of the number of trapped individuals, whereas UHI explained 20% of taxonomic diversity. Local vegetation height and cover were significant predictors of functional diversity, and explained 22% and 25% of variance, respectively. We conclude that locally applied planning measures could mitigate the loss of taxonomic diversity induced by the atmospheric UHI and promote the establishment of more diverse communities.
... This suggests alleyway resources were limiting and unable to support natural enemies, and hence unable to facilitate spill-over of natural enemies into the crop canopy. Although AMWT promoted the sown tussock-forming grass species within the sown alleyways (Mockford et al., 2023), which are typically associated with a more stable microclimate and can shelter insects from adverse climatic conditions (Collins et al., 2003;Luff, 1965;MacLeod et al., 2004), cutting to a height of 10 cm in both May and July is likely to have strongly affected the structure and function of the alleyway habitat, and removed shelter during the hottest and driest part of the year, preventing the habitat from recovering (Morris, 2000). Cutting also reduced the cover abundance of some of the sown forb species, such as Psoralea bituminosa, Salvia verbenaca, Hypericum perforatum, and Cichorium intybus (Mockford et al., 2023), which without cutting are expected to help support natural enemies by increasing the abundance and diversity of open flowers throughout the year (Mateos-Fierro et al., 2021). ...
... Salvia verbenaca, for example, provides flowers in early spring and autumn (Blamey and Grey-Wilson, 2004). It is likely that the removal of above-ground biomass for two consecutive years impacted the ability of the plant community to recover (Morris, 2000) and led to the reduced abundance and richness of natural enemies observed in year three. In the standard management treatment, however, sown forb species were retained in the wildflower strip, and tussock-forming grasses were able to grow taller through less frequent cutting, which boosted plant richness and the provision of resource for natural enemies. ...
Contemporary approaches to agriculture must be reimaged to include ecological techniques that maximise ecosystem services, so that food can be produced sustainably whilst simultaneously meeting yield demands. Pest regulation services, harnessed through the conservation of natural enemies in the agri-environment are an economically important service degraded by conventional citrus production practices. For the first time, a sown wildflower strip composed of native forbs and tussock-forming grasses has been investigated for its influence on natural enemies and their pest regulation services in citrus orchards. A novel management strategy was applied, using the predicted generation times of Aonidiella aurantii Maskell (Hemiptera: Diaspididae), a key pest in citrus, to determine whether cutting the wildflower strips could force spill-over of natural enemies onto the adjacent crop, enhancing pest regulation services. Three treatments applied to orange orchard alleyways were compared: i) a control treatment, the standard orchard practice of regular cutting to 5 cm throughout the year, ii) a sown wildflower treatment managed with cutting once a year in February to a height of 10 cm (standard management wildflower treatment, SMWT), and iii) the same sown wildflower treatment but managed with two additional cuts in May and June (active management wildflower treatment, AMWT). Orange tree canopies were sampled for natural enemies, and pest regulation services were quantified using sentinel prey cards baited with Ephestia kuehniella eggs. Natural enemy richness was greatest in canopies with SMWT, supporting a greater relative abundance of primary parasitoids and lower relative abundances of antagonists (ants) compared to the control. This was associated with enhanced pest regulation services (depletion of sentinel prey from baited cards), especially during the early summer months, which coincides with a critical period to control A. aurantii and other key citrus pests. In contrast, AMWT did not enhance natural enemy richness, and pest regulation services were diminished. This study suggests that leaving wildflower strips uncut throughout the season, as in SMWT, may help to mitigate pest incidence through enhanced pest regulation services. Further studies are now required to determine how this would influence populations of target pests.
... Whilst floral species richness had a positive effect across pollinator groups, there was little effect of vegetation height. However, taller swards and variation in vegetation structure can promote a diversity of microclimatic niches (Morris, 2000). Bumble bees often respond positively to taller vegetation as some species nest in tussocky grass (Kells & Goulson, 2003) and some butterfly species require more complex vegetation (Aguirre-Gutierrez et al., 2017). ...
... Intensive cutting removes pollinator foraging resources and reduces structural variation (Morris, 2000) and as such, there could be an opportunity to improve resource availability at solar parks by delaying vegetation management to after the pollinator active period. ...
There is increasing land use change for solar parks and growing recognition that they could be used to support insect pollinators. However, understanding of pollinator response to solar park developments is limited and empirical data are lacking.
We combine field observations with landcover data to quantify the impact of on‐site floral resources and surrounding landscape characteristics on solar park pollinator abundance and species richness. We surveyed pollinators and flowering plants at 15 solar parks across England in 2021, used a landcover map to assess the surrounding high‐quality habitat and aerial imagery to measure woody linear features (hedgerows, woodland edges and lines of trees).
In total, 1397 pollinators were recorded, including 899 butterflies (64%), 171 hoverflies (12%), 161 bumble bees (12%), 157 moths (11%), and nine honeybees (<1%). At least 30 pollinator species were observed, the majority of which were common, generalist species.
Pollinator biodiversity varied between solar parks and was explained by a combination of on‐site floral resources and surrounding landscape characteristics. Floral species richness was the most influential on‐site characteristic and woody linear feature density generally had a greater impact than the cover of surrounding high‐quality habitats, although drivers differed by pollinator group.
Our findings suggest that a range of factors affect pollinator biodiversity at solar parks, but maximising floral resources within a park through appropriate management actions may be the most achievable way to support most pollinator groups, especially where solar parks are located in resource‐poor, disconnected landscapes.
... We found a specific preference for open patches, interspersed with stones within vegetated areas, where prey abundance is expected to be higher (Morris, 2000). This underpins that a diverse habitat is necessary to sustain food availability for northern wheatears throughout their stay on the Alpine breeding grounds. ...
... Even though patches with bare ground and stones were preferred on a small scale, they lay within the territories in the study area where heterogeneous and productive grassland is the dominating habitat type. On the one hand, this result implies that northern wheatears selected productive areas for foraging that offer high arthropod abundance and diversity (Morris, 2000), which increases with vegetation height (Atkinson et al., 2004). On the other hand, high vegetation decreases visibility and access to the ground (Atkinson et al., 2004;Vickery & Arlettaz, 2012) and reduces the probability of a foraging attempt being successful (Dennis et al., 2008). ...
Organisms living in high-elevation habitats are usually habitat specialists who occupy a narrow ecological niche. To envision the response of alpine species to a changing environment, it is fundamental to understand their habitat preferences on multiple spatial and temporal scales. However, information on small-scale habitat use is still widely lacking. We investigated the foraging habitat preferences of the migratory northern wheatear Oenanthe oenanthe during the entire presence at a breeding site in the central Alps. We repeatedly observed 121 adult and juvenile individuals. We applied Bayesian logistic regression models to investigate which habitat characteristics influenced foraging habitat selection on a fine spatial scale, and how habitat use varied temporally. Throughout their presence on the breeding grounds, northern wheatears showed a consistent preference for a mosaic of stones and bare ground patches with slow-growing, short vegetation. The proximity of marmot burrows was preferred, whereas dense and low woody vegetation was avoided. After arrival at the breeding site, short vegetation, preferably close to the snow, was favored. The preference for open habitat patches that provide access to prey underlines the critical role of small-scale habitat heterogeneity for northern wheatears. The strong and consistent preference for a habitat that is under pressure from land-use and climate change suggests that this alpine bird species may be sensitive to habitat loss, leading to a potential range contraction. We highlight the need to conserve habitat diversity on a small spatial scale to ensure the long-term availability of suitable habitat for northern wheatears in the Alps.
... For this reason, the strips tend to lack a wildflower component and are botanically species-poor (Vickery et al., 2002). Introducing wildflowers has the potential to increase their biodiversity value through the provision of foraging resources for pollinating and phytophagous invertebrates , in addition to increasing the architectural structure of the sward for the benefit of predatory invertebrates such as spiders (Gibson et al., 1992a;Morris, 2000). The competitive strategies of many grasses used in the creation of these areas has meant that attempts to establish wildflowers into existing grassdominated buffer strips have proved problematic (Blake et al., 2011). ...
... Although plant community assemblage has been shown to be a key determinant for predatory taxa, including spiders , our responses suggest that other factors, besides wildflower cover, may be important for some species, such as members of the Linyphiidae. For example, previous studies have demonstrated the importance of sward structure and composition for spider abundance and species richness (Gibson et al., 1992b;Morris, 2000). In the present study, sward structure was lowest in those treatments receiving either scarification with wildflower seeds and graminicide, or graminicide only, supporting previous studies (Marshall & Nowakowski, 1991;Porter & Nowakowski, 1991). ...
Most agricultural grassland in lowland UK is species-poor and structurally uniform. Management intensification has had a deleterious affect on the biodiversity of invertebrates and the suitability of grassland as feeding and breeding habitat for birds (Vickery et al. 20001). The PEBIL project (Defra BD 1444: Potential for Enhancing Biodiversity in Intensive Livestock Farms) is investigating the effects of structural and plant species manipulation on the invertebrate communities of field margins. The different treatments are designed to test the effects of increasing amounts of sward structural heterogeneity, in terms of canopy height, architectural complexity & botanical composition, on faunal abundance and diversity as well as improving food resources for birds.
... Habitats that are more structurally complex M.D. Fraser, H.E. Vallin and B.P. Roberts Animal 16 (2022) 100671 have been found to host a greater variety of invertebrates, and attract a greater species richness, abundance and distribution of insectivorous and granivorous birds, small mammals and bats in comparison to uniformly structured habitats. It has been suggested that this is because spatially heterogeneous habitats offer a greater variety of microhabitats to support more species (Morris, 2000). More marked improvements in biodiversity (and productivity) can be brought about by increasing the number and diversity of plant species within pastures. ...
... Likewise, biodiversity benefits have been linked to periodic grazing via rotational (Ravetto Enri et al., 2017) and cell (Richards and Lawrence, 2009) grazing management systems, particularly where such systems specifically incorporate paddocks set aside for conservation purposes (Farruggia et al., 2012). Intermittent grazing not only gives slower-growing and preferentially grazed plants an opportunity to compete within the sward, it also promotes structural heterogeneity within a site, in turn benefitting invertebrates (Morris, 2000). ...
Grasslands dominate land cover nationally and globally, and their composition, structure and habitat value are strongly influenced by the actions of domestic and wild grazing animals that feed on them. Different pastures are characterised by varying opportunities for selective feeding by livestock; agronomically improved, sown swards generally consist of a limited range of plant species whereas longer-term leys and semi-natural grasslands are characterised by a more diverse mixture of plants. In the case of botanically diverse permanent pastures/grazing lands the dietary preferences of different grazers have a more pronounced effect on the botanical composition of the sward in the longer term. Selection of a dominant species within the sward can give less abundant components a chance to compete, increasing community evenness and species richness. Conversely, selection of minor components reduces sward compositional heterogeneity and hence plant species richness and evenness. Body size, gut type (fore-gut vs hind-gut fermentation), physiological status (growing, pregnant, lactating), metabolic status (extent of body reserves) and environmental conditions all influence the nutrient requirements of a given animal and related foraging priorities. The diet selected is also strongly influenced by the availability of preferred food items, and their vertical and horizontal distribution within the sward. In general, larger animals, such as cattle and horses, are less selective grazers than smaller animals, such as sheep and goats. They are quicker to switch to consuming less-preferred sward components as the availability of preferred resources declines due to their greater forage demands, and as a result can be very effective in controlling competitive plant species consistently avoided by more selective grazers. As a result, low-intensity mixed grazing of cattle and sheep has been shown to improve the diversity and abundance of a range of taxa within grazed ecosystems. Mixed/co-species grazing with different animals exploiting different grassland resources is also associated with increased pasture use efficiency in terms of use of different sward components and related improvements in nutritional value. In situations where cattle are not available, for example if they are not considered commercially viable, alternative species such as goats, ponies or South American camelids may offer an opportunity to diversify income streams and maintain productive and biodiverse pastures/grazing lands. Stocking rate and timing of grazing also have a considerable role in determining the impact of grazing. Regardless of the species grazing or the pasture grazed, grazing systems are dynamic since selective grazing impacts future availability of sward components and subsequently dietary choices. New technologies under development provide opportunities to monitor plant/animal interactions more closely and in real time, which will in future support active management to deliver targeted biodiversity gains from specific sites.
... Moreover, mostly all zones are mowed at least once in a season, which is not consistently meeting arthropod needs. Consequently, current mowing regimes for semi-natural and extensively used grasslands are suboptimal for providing food availability (Morris, 2000;Kruess and Tscharntke, 2002) and creating diverse grassland structures is crucial for arthropod shelter (Woodcock et al., 2007). Variations in plant growth, height and floral quality and availability across seasons, are all essential for pollinating insects (Potts et al., 2003), revealing limitations in current grassland management schemes. ...
... Arthropods represent a substantial part of earth's biodiversity (Morris 2000). They make up for the largest proportion of species richness at any spatial scale (Hammond 1992) so they are more representative for wholesale organismal biodiversity than any other group of organisms (Obrist & Duelli 2010). ...
A study on litter arthropod population was carried out in four tropical dry evergreen forests distributed two each in inland (sites KR & MM) and coastal (sites KK & OR) areas of peninsular India. A 1-ha plot (100m 100m) was established in all the four sites. At each site, arthropod samples were carefully collected from ten 15cm 15cm random samples along with litter materials in polythene bags. A total of 549 individuals representing 13 taxa were recorded. Shannon diversity index (H') was maximum for site KR (0.811), followed by sites OR, KK and MM. The abundance of litter arthropod was high for inland sites (282 individuals) than costal sites (267 individuals), and among the four sites, site MM had greater value followed by sites KK, KR and OR. Single factor ANOVA revealed that abundance of arthropod did not vary significantly between the four sites (F (3,48) = 0.017, p > 0.05). T-test also showed that there was no significant difference in arthropod abundance between the inland and coastal sites (t (13) = 0.266, p > 0.05). Overall, Araneae, Hymenoptera, Blattodea, Hemiptera and Isoptera dominated litter arthropod abundance of the tropical dry evergreen forests of peninsular India.
... protected as "sacred groves" based on the religious taboo of the local people (Pragasan and Parthasarathy, Insects share a large part of the global biodiversity 2005). However, they undergo different levels of (Morris, 2000) and at any spatial scale, they are the anthropogenic pressure at different sites. Literature maximum diverse group (Hammond, 1992) and are more survey revealed that so far only a few studies were representative than any other organism (Obrist and carried out on TDEFs in India (Parthasarathy and Duelli, 2010;Pragasan, 2013). ...
This study aimed to address the population changes in the forest floor litter arthropods of two tropical dry evergreen forests namely Kuzhanthaikuppam (KK) and Oorani (OR) located in India. Arthropod samples from the two forests were collected every month for one-year period. The richness of arthropods (size >3 mm) ranged from 8 to 12 taxa at KK and-2 from 7 to 12 at OR. The density of arthropods fluctuated from 257.8 to 1257.8 ind m at KK and from 266.7 to 1417.8 ind-2 m at OR. Statistical analysis (ANOVA) revealed that the diversity and the density of arthropods fluctuated significantly (P < 0.0001) at both the study sites.
... Grazing 439 had a pronounced negative effect on species richness in the seed rain and significantly reduced the seed 440 density of grasses while having no effect on forbs. This may be due to many forbs having evolved physical which strongly limits seed production (Morris, 2000). Nonetheless, high grazing pressure also increases the 445 availability of open soil gaps in the vegetation that may strongly favor the establishment of forbs following 446 a ruderal life strategy (Bråthen et al., 2021). ...
Seed rain, the amount of seeds reaching an area via primary or secondary dispersal, affects the regeneration of plant communities and shapes the trajectory of future community composition. In agricultural grasslands, the composition and density in seed rain are mainly driven by land use, but drivers of seed rain quality and quantity along land-use gradients are poorly understood. We studied the effects of land-use intensity (LUI), its components (i.e. fertilization, mowing, and grazing), productivity, and aboveground vegetation composition and richness on seed rain.
We collected the seed rain over a five-month period in 142 grasslands and identified emerging seedlings. Grass seedlings dominated seed rain most likely due to their high abundance in vegetation and intense and early seed set. Only ten species accounted for approximately 80 % of seedlings, with grasses such as Lolium perenne and Alopecurus pratensis being most abundant. Forbs such as Cerastium holosteoides and Veronica arvensis were abundant in seed rain despite lower cover, probably due to early and prolonged flowering and high seed production.
Seed rain of grasses and forbs reacted differently to LUI and vegetation richness, LUI effects on grass seed rain mainly determined total seed density. Seed rain richness first increased with LUI, but decreased at higher LUI levels. Consequently, seed rain richness consistently increased with vegetation richness. This is reflected by a decrease in the abundance of stress strategists and an increase in ruderals in seed rain with increasing LUI and decreasing vegetation richness.
Among LUI components, fertilization intensity most strongly affected seed rain density and composition, with negative effects at intermediate fertilization intensities. Mowing once a year increased seed rain density, whereas it decreased at higher mowing frequencies. Grazing intensity reduced overall seed density and richness by reducing grass seed density, while forb seed density remained unaffected.
Synthesis : Land-use intensity and aboveground productivity significantly influence the species composition and seed densities in the seed rain of temperate agricultural grasslands. Higher land-use intensity and productivity increased seed production but reduced taxonomic and functional diversity in seed rain and may negatively impact ecosystem stability and resilience.
... Mowing can cause direct mortality of arthropods, especially of those in egg or larval stages (Humbert et al., 2010). Furthermore, mowing can remove substrate that arthropods rely on for nesting and foraging, affect arthropods by changing plant species composition, by supressing woody vegetation, and by creating a uniform plant height that is less attractive for pollinators (Morris, 2000;Black et al., 2011). Therefore, the effects of mowing might be strongest on groups that rely on a tall vegetation, like Hemiptera and Hymenoptera (Proske et al., 2022;Steidle et al., 2022). ...
The intensification of agriculture has been identified as one of the main causes of arthropod declines. To halt the decline of arthropods, changes in farming practices and management of surrounding habitats may therefore be needed. A key challenge is to identify which changes in management approaches are most effective in restoring biodiversity. Therefore, this study examines arthropod abundance and diversity in different agricultural and semi-natural habitats, and among different management types. Arthropods were sampled three times in spring and summer of 2022 and 2023 with emergence traps in 128 unique sites in an intensively farmed area in Western Netherlands. These sites included a variety of crops as well as semi-natural habitats. Our study showed that on average the abundance and diversity of arthropods of several taxa was lower in crop habitats compared to semi-natural habitats. However, these effects strongly varied among crop species. For instance, alfalfa, spelt, spring and winter wheat fields (that often had a high plant cover) supported similar arthropod diversity and abundance levels as semi-natural habitats. Interestingly, in crop fields most variables related to field management, such as herbicide applications or amount of nitrogen fertilizers, did not show any significant relationship with arthropod abundances or diversity. The number of days after cultivation was an exception, and was positively related to total arthropod abundance, Hymenoptera and Collembola abundances, and Coleoptera family diversity. Within semi-natural habitats, number of days after mowing was positively related to total arthropod abundance, Diptera, Hemiptera and Hymenoptera abundances, and Hemiptera family diversity. Additionally, plant cover was positively related to total arthropod abundance. Overall, our findings suggest that crop species and management practices that increase plant cover in spring and early summer are increasing arthropod abundance and, to a lesser extent, higher-taxa diversity in intensively farmed agricultural landscapes.
... The native grassland (NG) area supported the highest number of arthropods in terms of individual count and species richness, highlighting the importance of undisturbed habitats in maintaining high biodiversity [58,59]. This is consistent with previous research, indicating that natural habitats typically support more diverse and stable arthropod communities due to the availability of various niches and less anthropogenic disturbance [60,61]. ...
Arthropods play a crucial role in ecological processes and agricultural productivity. Soil physicochemical properties, indicators of soil health, are closely linked to arthropod communities. Gravel-sand mulching, commonly employed in arid farming, initially enhances water retention and temperature regulation but may contribute to land degradation with prolonged use. This study investigated how varying tillage durations affected soil properties and arthropod diversity under gravel-sand mulching. The analysis employed multiple comparison methods, covariance analysis (ANCOVA), non-metric multidimensional scaling (NMDS), and redundancy analysis (RDA). The results indicated that while soil fertility was better preserved in cultivated fields compared to in the desert grassland, arthropod diversity significantly decreased with longer cultivation periods. A total of 1099 arthropods from 79 species were sampled, by Barber trap. The highest diversity was observed in native grassland (NG), with 305 arthropods from 39 species, while tillage 21 years (GPS-21Y) exhibited the lowest diversity, with only 103 arthropods from 6 species. Dominant species included the carnivores Labidura japonica and Cataglyphis aenes. The analysis revealed low similarity in arthropod communities between GPS-21Y and other fields and high similarity in soil physicochemical properties between NG and the transition zone (STZ). RDA showed available potassium (APP) was negatively correlated with arthropod species diversity and concentration, total Nitrogen (TN) was positively correlated with arthropod species diversity but negatively correlated with species concentration, total phosphorus (TP) was negatively correlated with arthropod species diversity and concentration. This study provides insights into the relationship between maintaining soil fertility and supporting arthropod diversity in grassland agriculture. While soil fertility and arthropod diversity were correlated, continuous cropping practices negatively impacted arthropod diversity, offering valuable information for pest management and sustainable agricultural practices.
... Compared to the other vegetation types, the riparian forest exhibits greater environmental heterogeneity, with higher values of plant richness, soil moisture, and leaf litter density. A heterogeneous environment positively impacts Collembola communities by altering spatial patterns such as microclimatic conditions and structural characteristics of various microhabitats [81,82]. This diversity supports the establishment and persistence of Collembola by offering a greater number of microhabitats for shelter, protection from predators, and enhanced food availability and variety. ...
Springtails, vital for ecosystem assessment, are often overshadowed by taxono-my-focused research, which mostly neglects their ecology and distribution, particularly in the Ne-otropical Region. The objective of this study was to identify how environmental factors, especially vegetation types, affect the availability of food resources for epiedaphic Collembola and influence their diversity patterns in three vegetation types (riparian forest, mangrove, and restinga) in the Canárias Island, in Delta do Parnaíba Environmental Protection Area, Brazil (APADP). We collected samples along 200 m transects in each vegetation type during the dry and rainy seasons. After, specimens were sorted, counted and identified. Alpha (species richness, Shannon, Simpson, and Pielou indices) and beta diversity (Whittaker index) were analyzed, along with environmental factors' influence through Redundancy Analysis (RDA). We sampled a total of 5346 specimens, belonging to three orders, eight families, 23 genera, 31 morphospecies, and one nominal species. Species abundance was positively influenced by soil moisture, plant richness, and leaf litter. The riparian forest sheltered a higher species richness and diversity, and its biotic and abiotic factors likely enhanced the food resource availability, including vegetal organic matter, fungi, and bacteria. These results provide the first taxonomic and ecological data on the Collembola fauna in the APADP.
... Derivado disso, ameaças diretas às populações de samambaias e licófitas ocorrentes na área de estudo foram observadas durante as amostragens, como o intenso pisoteio no entorno dos corpos d'água lênticos, a supressão do sub-bosque das matas secas e úmidas e a intensa herbivoria direta. A presença de gado na área, pode interferir nos padrões de diversidade pela alteração na estrutura da comunidade vegetal (Pillar & Vélez 2010), incrementando a heterogeneidade espacial dos habitats (Morris 2000), atuando como um fator de seleção, favorecendo a ocorrência de algumas espécies ou grupos funcionais em detrimento de outros (Cestaro et al. 1986, Müller & Waechter 2001, Záchia & Waechter 2011. Em relação ao pisoteio, foram observados impactos diretos na população de Regnelidium diphyllum. ...
O domínio Pampeano constitui um mosaico vegetacional de campo-floresta, que abriga uma alta riqueza de espécies,
incluindo as plantas vasculares dispersas por esporos. O objetivo deste estudo foi inventariar as samambaias e licófitas em
um fragmento do Pampa, localizado na Fazenda Estância da Quinta, no município de Rio Pardo, Estado do Rio Grande do
Sul. A amostragem ocorreu através do método de caminhamento expedito, realizada em 15 viagens de campo. O material
coletado foi identificado através de bibliografia especializada, com posterior incorporação no Herbário da Universidade
de Caxias do Sul (HUCS). Atributos ecológicos, geográficos e de conservação das espécies foram registrados em campo e
através de busca bibliográfica. O inventário resultou no reconhecimento de 46 espécies de samambaias e uma licófita (Isoetes
weberi Herter), pertencentes a 13 famílias. O hábito terrestre (51%) foi predominante, bem como a ocorrência preferencial
no interior dos fragmentos florestais (66%). Duas espécies constam em listas de espécies ameaçadas de extinção. Nossos
dados reforçam a importância da preservação do mosaico paisagístico do Pampa para manutenção da diversidade deste
grupo de plantas do RS.
... The habitat management practices exert a considerable influence on the communities of arthropod species, including ground beetles. The integration of the theoretical and experimental aspects of ecology with the practical knowledge of managers is vital for effective biodiversity conservation [39]. Grasslands, especially those under moderate human influence, can be very species-rich areas. ...
This study, conducted in 2020–2022, was designed to determine the impact of livestock grazing on habitat biodiversity and Carabidae beetles. Two research plots (a meadow and a pasture) were established on a farm in the village of Otapy, located in the agricultural catchment area of the Nurzec River in Eastern Poland. They were located next to each other so that they would possess the same set of atmospheric phenomena and processes shaped by the physical and geographical characteristics of the area. The study showed that the pasture was the richest in terms of the magnesium and calcium contents, while the meadow had significantly higher levels of phosphorus and zinc. The study also showed some differences in the abundance and species composition of plants and animals. The meadow had higher biodiversity, while the pasture was dominated by grasses. A disparity in the abundance of individual species was also presented. The study indicated the preference of individual species for particular forms of land use. Anisodactylus binotatus, Harpalus rufipes and Poecilus cupreus were most abundant in the meadow, while Carabus granulatus and Pterostichus melanarius were mostly represented in the pasture. The number of species, on the other hand, was the same. Our research concluded that proper landscape management through different uses affects plant and beetle diversity and soil element content.
... In the absence of grazing by large herbivores, mowing is a necessary management action in most of the West European grassland systems (Vera 2000, Wallis de Vries 1995: it prevents the grassland from developing into forest. However, mowing also has negative effects on insects (Morris 2000): it leads to direct mortality caused by cutting the vegetation and local soil compaction caused by mowing machines (Humbert et al. 2009, Wallis de Vries & Knotters 2000. Indirectly, mowing reduces food availability, microclimatic heterogeneity and reproductive habitat (Lebau et al. 2015). ...
Flower-rich grasslands are an important habitat for bumblebees.
These grassland types are becoming increasingly scarce and therefore
many bumblebee species are under pressure. Over 205,000 hectares of
mesotrophic grassland are left in the Netherlands, but little is known
about their current value for these insects. We therefore studied species
richness and abundance of bumblebees in four grassland types on fifteen
locations on peat and clay soils in the Netherlands in 2018 and 2019. In
total, we found 674 bumblebees of eight different species. Abundance and
species richness were significantly lower in meadow bird grasslands than
in flower-rich grasslands, hay meadows and road verges. This was mainly
caused by a scarcity of flowers in the meadow bird reserves due to high
nitrogen fertilization inputs and large scale mowing after the end of the
bird breeding season. Suggestions for management improvements that
favour bumblebees are made.
... Esta presencia de ganado en la proximidad del nido durante la época de reproducción de la especie ha sido ilustrada también por Llopis et al. (2014) en el área de estudio y se correspondería con un escenario donde el pasto no crece ni se densifica como en los cultivos de hierba de las explotaciones donde se mantiene el ganado estabulado. El pastoreo moderado es, además, selectivo con lo que mantiene unos pastos heterogéneos con más plantas e insectos (Morris 2000, Vickery et al., 2001 por lo que la pérdida de este sistema tradicional de manejo del ganado parece estar detrás de la pérdida de aves insectívoras que se alimentan en los prados de Europa (Strebel et al., 2015;Bowler et al., 2019). En circunstancias de pastoreo moderado y disperso, los alcaudones dispondrían de superficies accesibles a su técnica de caza al acecho y se beneficiarían, además, del incremento de potenciales presas asociadas al ganado y sus excrementos (Geiger et al., 2010;Šálek et al., 2020). ...
El alcaudón dorsirrojo presenta un progresivo declive en la península Ibérica por lo que es interesante conocer las causas de este proceso. Analizamos en este estudio los factores determinantes de su distribución, abundancia y éxito reproductor en Bizkaia (Comunidad Autónoma del País Vasco). Para ello, muestreamos entre 1 y 4 veces 675 cuadrículas de 1x1 km en la primavera de 2021. Además, cuantificamos la presencia de ganado en las cuadrículas muestreadas, la densidad local de ganado y de explotaciones ganaderas, la cobertura de campiña (prados y setos), la huella humana y la altitud, que utilizamos como un subrogado del clima. Los análisis preliminares (modelos lineales generalizados, GLM) sugirieron que la presencia de ganado, la densidad de explotaciones y la cobertura de campiña se asociaban positivamente con la aparición de los alcaudones. Se observó también un fuerte efecto del número de visitas por lo que se estudió la probabilidad de detección de la especie mediante una modelización jerárquica de la ocupación. Este nuevo análisis desveló una probabilidad de detección de 0,68 por visita (error estándar= 0,134), además del fuerte efecto de la cobertura de campiña, presencia de ganado y densidad de explotaciones en la probabilidad de ocupación del alcaudón dorsirrojo. Estos resultados nos permitieron calcular la presencia real de la especie en 236 cuadrículas (rango=169-311) de las 675 muestreadas. Considerando que se prospectó el 46,4% del hábitat potencialmente adecuado para la especie en el área de estudio, se estimó que la población del alcaudón dorsirrojo en Bizkaia rondaba las 517 parejas reproductoras (rango=373-679), una población mucho menor que la predicha por otras aproximaciones previas. El número de pollos volantones observados en 128 parejas reproductoras osciló entre 0 y 4 (media 1,6 pollos por pareja), con un 73 % de las parejas con uno o más pollos (un porcentaje similar al éxito reproductivo de otras poblaciones ibéricas). En este caso, el número de pollos solo se asoció significativamente a la cobertura de campiña. Los resultados de este estudio sugieren que la distribución de la especie parece estar fuertemente constreñida por la disponibilidad de campiña y la actividad del ganado, responsable de la creación de pastizales y prados heterogéneos en los que puede encontrar sustratos de caza.
... A Természetvédelmi Terület kezelési terve szerint a területen végezhető legeltetés és kaszálás, de szigorúan a terület állateltartó képességéhez igazodva -a terület maximum 2/3-a kaszálható, és 0,2 állategység/ha legeltethető (A Gyöngyösi Sárhegy Természetvédelmi Terület kezelési terve). Erre szükség is van, hiszen ezek a műveletek kedvező hatással vannak a fajdiverzitásra (Morris, 2000), visszaszorítják a kompetítor fajokat (Curry, 1994), elősegítik a propagulumok terjedését, biztosítják az ökoszisztéma-szolgáltatások folyamatos fenntartását (Ryser et al., 1995;Fiala et al., 2003;Bartha, 2007;Virágh et al., 2008). A kaszálórétek és a fás legelők Közép-Európa leginkább fajgazdag társulásai közé tartoznak (Steffan-Dewenter és Leschke, 2002;Losvik, 1999;Stampfli és Zeiter, 1999;Ilmarinen és Mikola, 2009). ...
We studied the vegetation of grasslands on the Sár Mountain, in Gyöngyös. The areas are mowed regularly by the Bükk National Park and mechanical shrub control was done as well. The effects of these habitat management techniques were investigated on grasslands of different degradation levels. Coenological studies were made between May and June in 2013 with 2×2 m relevés. The study areas were characterised according to nature conservation value categories and life forms. Our results showed that the above mentioned management techniques had positive effects on the diversity of grasslands. On the managed grasslands the abundance of woody species decreased, while the abundance of annual and perennial grass species and dicotyledonous herbaceous species increased. The highest species number (58-78) was recorded in the case of control areas. The number of species was high (47-49) in the areas managed by mowing and mechanical shrub control. The lowest species number (43) was recorded in the areas which were not mowed after mechanical shrub control. According to the nature conservation value categories the number of protected species was the highest in the control areas. Our results approved that regular mowing is needed after mechanical shrub control to sustain the diversity of abandoned grasslands in the long run.
... Hazai területeken e negatív hatásokat ellensúlyozhatja a legeltetés és kaszálás Valkó et al., 2009Valkó et al., , 2011Valkó et al., , 2012Deák és Tóthmérész, 2005, 2007Penksza et al., 2013;Zimmermann et al., 2011;Szabó et al., 2011;Szentes et al., 2009a, b;Török et al., 2009a, b;Nagy és Tasi, 2017). Ez olyan kismértékű zavarásokat jelent, mely a fajdiverzitásra jelentős pozitív hatással vannak, ellentétben a korábbi évtizedek "rezervátum-szemléletétől" (Morris, 2000;Deák et al., 2015). E pozitív hatások elsősorban a propagulumok könnyebb terjedésében, valamint az erősen kompetitív, illetve invazív fajok visszaszorulásában nyilvánulnak meg (Ryser et al., 1995;Fiala et al., 2003;Bartha, 2007;Virágh et al., 2008). ...
A természetvédelmi kezelések alkalmával a hegyi réteken leginkább a cserjésedés visszaszorítása a cél. E feladatot 2012-ben több Parádóhuta melletti gyepfolton a Bükki Nemzeti Park Igazgatóság látta el. A vizsgált foltok közül a mintaterületünkön 2012 óta viszont nem történt beavatkozás, a vegetáció kialakításáért és a benne történő változásért kizárólag a vadak a felelősek. A cönológiai vizsgálatokat 2×2 m-es kvadrátokban végeztük, ahol a fajok borítási értékei lettek megadva. A vegetációs adatokat klaszteranalízis és detrendált korreszpondencia-elemzés (DCA) alkalmazásával értékeltük. A mintaterületen csak a vadrágásnak köszönhetően 6 éven keresztül (2012-2017) a természetes fajösszetételű vegetáció alakult ki. Ez alatt az időszak alatt a fásszárú fajok nem váltak dominánssá, mint az várható lett volna, hanem stagnált, sőt egyes pontokon jelentősen csökkent a borításuk. Itt a magára hagyott területen potenciálisan a cserjésedés által veszélyeztetett gyeptársulásokban a nagytestű vadak szabályozták a fásszárú fajok borítását, ezzel jelentős szerepet játszhattak a természetközeli állapotok fenntartásában. Az utolsó két évben (2018-2019) jelentős változás történt. 2018-ban közel 10 ha-on cserjeirtást végeztek, így a vadállomány „legelő” területe több, mint a kétszeresére nőtt. A vadállomány ekkor már a kiterjedt területen nem tudta visszaszorítani a cserjésedést. 2019-re az évelő lágyszárúak fajösszetétele nem változott jelentősen, de a borításuk jelentős mértékben csökkent, és a cserjék törtek előre. 2018-ig az inváziós fajok (I) borítása viszonylag állandónak mondható, a 2019-es évben viszont a borításuk növekedni kezdett. A gyep diverzitási értéke is csökkent a 2019-es évre. A vadhatás elmaradásával a gyep fajösszetéte, ha még nem is változott jelentős mértékben, de a borítási értékek jól jelzik, hogy a becserjésedés erősödni fog, és várható, hogy a lágyszárú fajok nagy része is vissza fog szorulni.
... Számos kutatás mutatott rá a kaszálás és cserjeirtás ellenkező előjelű hatásaira Valkó et al., 2009Valkó et al., , 2011Valkó et al., , 2012Deák és Tóthmérész, 2005Penksza et al., 2007Penksza et al., , 2008Penksza et al., , 2010Penksza et al., , 2013Zimmermann et al., 2012;Szabó et al., 2010Szabó et al., /2011Szabó et al., , 2011Szentes et al., 2009a, b;Török et al., 2009a, b;Mészáros et al., 2016). Az ilyen típusú kismértékű zavarásokra sok esetben szükség van a gyepben, mivel a fajdiverzitásra kedvező hatással vannak (Morris, 2000;Deák et al., 2015;Halász et al., 2015;Penksza et al., 2009aPenksza et al., , b, 2016Vida et al., 2008;Deák et al., 2014;Kovács-Hostyánszky et al., 2013). Elmaradásuk igen gyorsan a gyepek becserjésedéséhez is vezethet (Ölvedi, 2010;Sendžikaite és Pakalnis, 2006;Stampfli és Zeiter, 1999;Uj et al., 2013;Pápay és Uj, 2012;Erdős et al., 2013Erdős et al., , 2014aHalász, 2016). ...
Az antropogén eredetű gyepes területek Magyarország leginkább fajgazdag élőhelyei közé tartoznak, ami különösen érvényes a hegyi rétekre, de a középhegységi szárazabb lejtők gyepeire is. Fennmaradásukat több tényező veszélyezteti, így a természetes szukcesszió is. A természetvédelmi kezelések egyik feladata a cserjésedés visszaszorítása, vagy cserjeirtással újabb élőhely-foltok kialakítása. A sár-hegyi mintaterületeinken cserjés, száraz-tölgyes, pionír rezgőnyár dominálta vegetáció típusban kialakított, különböző módszerrel kezelt gyepfoltok vegetációját hasonlítottuk össze 2×2 méteres kvadrátok alkalmazásával. A jelen munkában a 2013. és a 2017. évi adatokat közöljük. A felvételeket természetvédelmi mutatók (szociális magatartásformák, természetvédelmi értékkategóriák, Pignatti- és Raunkiaer-féle életformák), valamint statisztikai módszerek (klaszter- illetve DCA-analízis) segítségével elemeztük. Eredményeink egyértelműen rámutattak a természetvédelmi kezelés szükségességére a gyepfoltokon. A már 2013-ban is rezgő nyár (Populus tremula) csemeték által dominált területet a fásszárú fajok 2017-re teljesen összefüggően borították, a lágyszárú gyomokat is kiszorítva, így itt a gyep kialakítására rendszeres beavatkozás nélkül nincs lehetőség. A kezelt (cserjeirtott és kaszált), majd 2012-ben felhagyott gyepeken is megindult a cserjésedés, ami a 2013-ban még tömegesen jelen levő védett árvalányhaj-fajok (Stipa spp.) szinte teljes eltűnéséhez vezetett. Ezzel szemben a vizsgálatunk időtartama alatt is, és mintegy 20 éve folyamatosan kaszálással kezelt területek vegetációja nem változott lényegesen, a zavarásra, illetve természetességre utaló fajok borításának aránya stabil maradt. Az eredmények alátámasztják, hogy a jövőben továbbra is szükség van a száraz tölgyes, bokorerdő, cserjés helyén kialakított gyep fenntartásához a rendszeres kaszálásra, illetve esetenként cserjeirtásra is, így stabilizálva az élőhelyek magas fajdiverzitását.
... A kisléptékű zavarásra tehát szükség is van, hiszen ezek a műveletek kedvező hatással vannak a fajdiverzitásra (Morris, 2000;Borhidi, 2003), visszaszorítják a kompetitív fajokat (Curry, 1994), elősegítik a propagulumok terjedését, biztosítják az ökoszisztéma-szolgáltatások folyamatos fenntartását (Ryser et al., 1995;Fiala et al., 2003;Bartha, 2007;Virágh et al., 2008), így a kaszálórétek és a fás legelők Közép-Európa leginkább fajgazdag társulásai közé tartoznak (Steffan-Dewenter és Leschke, 2002;Losvik, 1999;Stampfli és Zeiter, 1999;Ilmarinen és Mikola, 2009). Ha abbamarad a kaszálás, illetve a legeltetés, az a terület cserjésedéséhez, beerdősüléséhez vezethet (Ölvedi, 2010;Sendžikaite és Pakalnis, 2006;Willems, 1983;Saláta et al., 2011;Uj et al., 2013;Pápay és Uj, 2012), így természetvédelmi szempontból kézenfekvő megoldás lehet ezeken a területeken a kaszálás (vagy legeltetés) visszaállítása (Ölvedi, 2010;Deák és Tóthmérész, 2005Stampfli és Zeiter, 1999;Penksza et al., 2007Penksza et al., , 2008Penksza et al., , 2010Zimmermann et al., 2011;Szabó et al., 2011;Harcsa et al., 2008;Bölöni et al., 2008;Török et al., 2009b), valamint a legeltetésnek az állattenyésztésben és a termék-előállításában is meghatározó szerepe van (Póti, 1998;Bedő és Póti, 1999;Bedő et al., 2005;Póti et al., 2007;Pajor et al., 2007). ...
Munkánk során Fallóskút melletti gyepterületeken végeztünk vizsgálatokat. A Bükki Nemzeti Park Igazgatóság 2012-ben cserjeirtást végzett a területen. A kutatás során a természetvédelmi kezelések vegetációra gyakorolt hatását vizsgáltuk. A felvételeket 2013-2015 májusa és júniusa között készítettük, 2×2 m-es kvadrátokat alkalmazva és a fajok százalékos borítási értékét adva meg. A vizsgált vegetáció típusokat a Borhidi-féle relatív növényökológiai mutatók (Borhidi, 1995) közül az NB (nitrogén igény relatív értékszámai) és a WB (relatív talajvíz- illetve talajnedvesség indikátor számai) alapján értékeltük. A természetvédelmi értékkategóriák (TVK) megoszlását Simon (2000) szerint, a szociális magatartástípusok (SZMT) alapján elvégzett értékelést pedig Borhidi (1995) alapján végeztük. Az adatok értékelésekor klaszteranalízist és detrendált korreszpondencia elemzést (DCA) alkalmaztunk. A fajok életforma kategóriái (Raunkiær, 1934; Pignatti, 2005) alapján is értékeltük a területeket. Az eredmények alapján a természetvédelmi kezelés, azaz a cserjeirtás pozitív hatással volt a gyepek fajgazdagságára. A kezelt gyepterületeken a fásszárú növények visszaszorultak, átadták a helyüket az évelő pázsitfüveknek, illetve kétszikű lágyszárúaknak. Az eredmények alapján megerősítettük, hogy az egykor intenzíven hasznosított, de ma már felhagyott gyepekben a cserjeirtást követően is folyamatos utókezelést kell biztosítani, hogy a terület fajgazdagsága fennmaradjon.
... Swengel [80], studying grass prairie and pine barrens, found that for the conservation of specialized butterfly species, the consistency of management within a site along with diversity between sites was desirable. And Morris [87], studying grasslands, stressed the importance of integrating theoretical and experimental aspects of grassland ecology with the practical knowledge of reserve managers and conservation officers. ...
The aim of the study was to determine the influence of differentiated landscape management on the distribution and abundance of butterfly species. The question was raised with regard to which land use type benefited butterflies, and which affected them, that is: under which management type does biodiversity increase, and under which is it depleted? The spatial and abundance distributions of the examined butterfly species diverged considerably. The observed differences between the abundance distributions may be due to diverse conditions in the small-scale environments or specific food preferences of individual species. The diversified management of the “Krzywda” landscape fosters the abundance of mesophilic and ubiquitous butterfly species, whereas xerotermophilic and hygrophilous species are not fostered. The transects established on the fallow land with harvested biomass as well as that with unharvested biomass and in the forest ecotone showed that the fallows were characterized by the highest abundance of butterflies, and the greatest number of plant species was recorded there. Mown fallow lands with not harvested biomass as well as forested areas fostered polyphagous and monophagous butterfly species. Oligophagous butterfly species were fostered by mown fallow lands with not harvested biomass. Unmown meadows, the ecotone marshland and fallow, as well as unmown fallow lands did not foster butterfly abundance. This most likely means that land management can influence the food base of butterflies, and consequently, their abundance. The stage of succession as well as the homogeneity of the area in terms of vegetation had the strongest filtering effect on the occurrence and distribution of butterflies among the analyzed variables. The number of species as well as their abundance was higher on transects classified as young successional stages on which successional processes were artificially inhibited by mowing and biomass removal. Advanced environmental engineering enables humans to influence species composition in a given ecosystem to achieve a desired result. There is no doubt that human activity will be successful when the needs of individual species in a given environment are accurately understood.
... Likewise, only four of the studies looked at the plant community in conjunction with the insect group, making it impossible to draw any conclusions on the influences of grassland abandonment on the overall insect communities. The decrease in disturbance is also known to explain an increase in abundance and diversity in arthropod communities (Morris, 2000), especially for insects that are also strongly related to soil (i.e., soil larvae, dormancy), which may be promoted by the lack of disturbance and accumulated litter during abandonment. ...
Grasslands are globally distributed and naturally occurring; however, in Europe,most grasslands are anthropogenically created or altered by livestock grazing or mowing. Low-intensity use and management have led to species-rich communities in European grasslands. The intensification of crop production and livestock farming with stabling throughout the year has led to an abandonment of grasslands that are no longer economically profitable. In this study, we looked at the influence of grassland abandonment on biodiversity. We hypothesized that abandonment of grasslands decreases the overall biodiversity, but has different effects depending on the focal taxonomic group (i.e., vascular plants, insects, or birds). We also hypothesized that the type of management before abandonment, the type of grassland, and the time after abandonment would influence grassland biodiversity. We conducted a Web of Science search, with pre-defined terms, to find articles that compared biodiversity of managed and abandoned grasslands in Europe.
... In these meadows, a wide variety of vegetation was also found, which undoubtedly influences invertebrate diversity. Many authors have shown that the high diversity and complexity of grassland plant groupings positively affect insect diversity (Morris, 2000;Vickery et al., 2001;Kruess and Tscharntke, 2002;McCracken and Tallowin, 2004;Moreira et al., 2016;Ebeling et al., 2018). ...
Agriculturally used meadows are habitats whose biodiversity depends on anthropogenic disturbances such as fertilization or mowing. Intensified agricultural practices (too frequent mowing, use of mineral fertilizers and insecticides) lead to declines in the abundance and species diversity of the biota inhabiting them. The intensification of agricultural production in north-eastern Poland relates primarily to the increase in cattle numbers and the intensification of grassland management, but many areas were included in Natura 2000 network. Our study was aimed at indicating the impact of diverse use of meadows on the species richness and diversity of invertebrates, amphibians, and birds in the grasslands of Narew river valley, Special Bird Protection Area, where the intensification of grassland use was noted in the last decades, and part of the meadows was included in the agri-environmental program. The agri-environmental program is a very good tool for the protection of grassland biotic diversity. The highest taxonomic richness and diversity of the studied animal groups were found in meadows included in these programs with extensive use, while the lowest was in the over- and intensively used meadows fertilized with mineral fertilizers and liquid manure. Only the meadows in the agri-environment program were inhabited by the fire-bellied toad and the tree frog - amphibians from Annex IV of the Habitats Directive. The number of breeding bird species globally threatened (IUCN Red List), listed in Annex I of the EU Birds Directive, and with negative population trend in Europe (SPEC1-3) was highest in meadows included in EU conservation programs. The main factors reducing biotic diversity in the grassland of flooded river valley were the high number of grassland mowing per season, intensive fertilization, especially with liquid manure, the great distance of meadows to the river, low soil humidity, and low share of shrubs and trees in the meadows border zone.
... Landscapes rich in insects consist of a fine patchwork of diverse successional stages, subject to disturbances of varying intensities and thus supplying diverse resources within insect individuals' movement ranges (Cremene et al., 2005;Dennis, 2010;Habel et al., 2022;Loos et al., 2014;Thomas et al., 2011). As such conditions typically exist under preindustrial land uses (Morris, 2000;Ansell et al., 2016;Bonari et al., 2017), researchers have been pertinently asking which processes would maintain such conditions in the pre-cultural past. With the growing awareness of megafauna's role in ecosystem functions (Vera, 2000;Smith et al., 2016) and of the severity of the late Quaternary defaunation (Martin & Klein, 1989;Dirzo et al., 2014), vertebrate megaherbivores are increasingly viewed as instrumental for maintaining the diversity of natural ecosystems (Bunzel-Drüke et al., 2019). ...
... Cases when site conditions modulate the impacts of conservation interventions might be rather common (e.g. Morris (2000), Helden et al. (2020), Dumont et al. (2020), Bussan (2022)) and if ignored, they may result in undesirable outcomes of well-intended activities. This highlights the necessity to flexibly adapt vegetation management to both local variation amongst sites and interannual variation in such aspects as rainfall or phenology. ...
A selection of sites occupied by the EU-protected marsh fritillary ( Euphydryas aurinia ) in western Czech Republic were subjected to a vegetation survey 15 years ago and again recently. In the 66 time-replicated 25 m ² plots from 12 sites, representing the diversity of E. aurinia -occupied oligotrophic grasslands in the Slavkovský les Protected Landscape Area (and covering a fifth of the currently-occupied Czech sites), we recorded quantitative representation of vascular plants and mosses. We analysed the data using multivariate ordinations, asking how the vegetation changed between the surveys, how was it affected by the conservation management applied and how it affected occupancy by the butterfly larval nests; the vegetation patterns were interpreted using Ellenberg’s plant indicator values. Between the two surveys, the overall representation of the larval host plant, Succisa pratensis , did not change; tree and herbs layers (both grasses and forbs) increased and the moss layer decreased. Across surveys, the main driver of vascular plants’ species composition was moisture, followed by soil reaction and nitrogen, whereas in mosses, nitrogen was the main factor. The main change between the surveys was the increase of nitrogen accompanied by decreased light, probably due to increase of competitively strong plants. Butterfly occupancy declined at sites with high soil moisture and increased at sites with higher soil reaction. Mowing of moist nitrogen-rich sites, but not drier nitrogen-poor sites, increased occupancy, illustrating the need for context-dependent interventions. All the evidence thus shows that E. aurinia prefers drier, warmer and less acidic conditions within the generally moist acidic grasslands and that ongoing eutrophication represents a potential problem in the future.
... In contrast, Neuroptera was more strongly influenced by the Shannon-Wiener index as it requires food quality rather than quantity. Other insect orders may be more strongly influenced by plant community structures as they tend to have specific habitat requirements, such as for refugees or oviposition [61]. In terms of insect species, the abundance of the six dominant species was positively associated with the Shannon-Wiener index (Figure 8). ...
Insects are important components of biodiversity and play significant roles in the steppe ecosystem. They are abundant, easy to sample, and sensitive to changing conditions, making them useful indicators of environmental changes. This study aims to describe patterns (α and β) of insect diversity across two steppe types (a typical steppe and a desert steppe) along the Eastern Eurasian Steppe Transect (EEST), as well as evaluate the effects of environmental variables in determining these patterns and the influence of plant diversity alterations on these effects. To this end, we collected 5244 individual insects and found an n-shaped diversity distribution along the latitudinal gradient and a significant difference in insect communities across the two steppe types. Further, the Mantel test and path analysis indicate that climate and grazing activities combine to influence insect diversity, and these effects are mediated through plant diversity, strongly supporting the role of bottom-up effects in situations of climatic and grazing pattern changes. Moreover, the contribution of plant diversity varied with steppe types and insect functional groups, with greater effects seen in the typical steppe and herbivorous insects. This indicated the importance of protecting species diversity in steppes through managing plant diversity and assessments of local environmental factors such as grazing intensity and temperature.
... Vegetation structure is a key factor for grassland fauna (Duffey et al., 1974;Morris, 2000), especially Orthoptera. Clarke (1948) and Gardiner & Hassall (2009) note that vegetation height / density is the most important habitat factor for grasshoppers, particularly in respect to the influence on microclimate. ...
The effects of lagomorph grazing on the Orthoptera of a small hill at Lound Lakes (Suffolk, UK) were studied during the summer of 2020. The transect counts of Orthoptera revealed low sward height due to high rabbit Oryctolagus cuniculus (Linnaeus, 1758) grazing on the high slopes which led to the general absence of tall grass species such as the Common Green Grasshopper Omocestus viridulus (Linnaeus, 1758) and Roesel's Bush-cricket Roeseliana roeselii (Hagenbach, 1822). Only nymphs and Field Grasshopper Chorthippus brunneus (Thunberg, 1815) adults were found in any number on the higher slopes, perhaps utilising the short swards and bare earth as basking habitat. The lower slopes and pastures supported tall-grass Orthoptera due to the absence of rabbit grazing and tussocky grassland.
... Orthoptera was favored by a low cover and low height of plants in the HG sites, indicating that Orthoptera species were influenced by grazing through modifications in the plant community structures, which is consistent with the results of recent findings (Schwarz and Fartmann, 2022). In contrast, Diptera and Hymenoptera were more strongly influenced by plant height as they tend to have specific habitat requirements, such as for refugees or oviposition (Morris, 2000). ...
For the past several decades, both species biodiversity and productivity of desert steppe have been reduced due to excessive use and climate factors. To counteract this, Chinese government has supported large-scale grassland ecological restoration programs since the year 2000. The policy needs a standard for the evaluation of the effects of such restorative measures on the grasslands after decades. Grassland insect diversity plays an important role in the maintenance of plant species and functional diversity. To understand the relation of grazing management and insect diversity, we use a complete two factor design, two fencing periods (3 or 7 years) and three grazing intensities (0, 6, or 12 sheep per ha), to examine the response of the insect diversity to fencing and grazing in desert steppe. We found almost no significant differences in either plant or insect species diversity between the sites fenced for 3 and 7 years, as the pressure of grazing increased, insect diversity decreased to a greater extent at 7-year enclosure sites than at 3-year sites. We recommend the most suitable grazing intensity for the sustainability of biodiversity of the desert steppe in Inner Mongolia is light grazing (8 sheep/ha 0.5 yr⁻¹), and the most suitable fencing period is three years, which suggest that policies that remove livestock from the desert grassland for long periods (7 + years) are not beneficial for maintaining insect diversity, and heavy grazing lead ecological environment weaker and insect diversity decreasing. Thus, periodic livestock grazing is important in the design of management actions to preserve biodiversity.
... Our findings highlight that habitat suitability for grassland fauna can shift over very short temporal scales. Similar patterns of shifting habitat mosaics have emerged in other grassland systems (e.g. for arthropods in British grasslands [Morris, 2000] and bird communities in North American prairies [Hovick et al., 2015]). Furthermore, shifting mosaics of vegetation structure have been identified as a central paradigm to conservation of small mammal populations in some agricultural landscapes (Fuhlendorf et al., 2010). ...
In many parts of the world, livestock production and biodiversity conservation are important land uses of native grasslands in agricultural landscapes. Approaches to managing grasslands typically differ between production farms and conservation areas as they have different goals. Such differences may have consequent effects on the spatial and temporal habitat suitability for grassland fauna. In semi‐arid grasslands of south‐eastern Australia, the critically endangered Plains‐wanderer (Pedionomus torquatus) is a grassland habitat‐specialist bird that can occur on land managed for livestock production and conservation, but it is unclear if, and when, habitat suitability is affected in each land‐use type.
Here, we investigate how land‐use type (livestock production, conservation) and rainfall (preceding accumulated rainfall) affect habitat suitability for the Plains‐wanderer using 11 years of bird occurrence and remotely sensed habitat structure data.
We found habitat suitability for the Plains‐wanderer was driven by an interaction between land use and rainfall, with conservation areas supporting larger areas of preferred habitat structure during dry periods but less during wet periods. By contrast, Plains‐wanderers were more likely to occur on livestock production farms during wet periods. We speculate this is because higher grazing pressure on livestock production farms was able to limit biomass accumulation and, hence, maintain more areas of preferred habitat structure.
Our findings show that land used for livestock production can complement conservation areas by providing preferred habitat for the Plains‐wanderer during climatic periods that promote grass growth. Furthermore, we highlight that land use and climate are important temporal drivers of grassland dynamics, and approaches to biodiversity conservation should consider how patterns of habitat suitability may shift across landscapes over time. Strategic, landscape‐scale planning and effective agri‐environmental initiatives will be critical to the future of grassland birds such as the Plains‐wanderer.
... On the other hand, lower vegetation is not detrimental to all arthropods. For example, visual hunter arthropods may benefit from reduced vegetation (Morris, 2000), and it may also be beneficial for species that prefer warmer and drier microclimates (Zhu et al., 2020). In the present study, some steppe-associated species were also able to colonise and use the grazed meadow vegetation in large numbers. ...
Livestock grazing is one of the most common management practices for grasslands and can greatly affect their biodiversity. However, arthropod diversity response patterns to grazing regimes are difficult to predict. We conducted a short-term grazing exclusion experiment in traditionally managed alkali grasslands in Hungary to investigate differences between grazed and ungrazed vegetation for different arthropod groups. The experiment was laid out in a full factorial design, with twelve 50 × 100 m short-term grazing exclosures in vegetation types with high (alkali wet meadow) and low productivity (alkali steppe). We sampled ground beetles and spiders with pitfall traps and true hoppers by sweep netting. We used vegetation type (wet meadow vs dry steppe), management (grazed vs ungrazed) and their interaction as fixed effects in mixed models. We found higher species richness and activity density of spiders and ground beetles in the more productive wet meadow vegetation, where the community structure of each arthropod group also shifted toward hygrophilous species. Significant interactions between vegetation type and management indicated a dependence of management effects on vegetation types: arthropod community structure shifted towards hygrophilous species in ungrazed meadows, but not in ungrazed steppe sites. True hopper abundance was higher in grazed meadow sites, but lower in grazed steppe sites, compared to ungrazed sites. True hopper community structure shifted toward generalist herbivores in ungrazed sites, regardless of vegetation type. We concluded that vegetation types determine arthropod communities and modulate the effects of grazing on arthropods. Our results suggest that moderate disturbance from low-intensity grazing has a positive or neutral effect in wetter, more productive vegetation, but a negative or neutral effect in drier, less productive vegetation, depending on the arthropod group. Herbivorous insects that dwell on plants are particularly affected by management because they are more susceptible to direct impacts, such as unintentional predation by grazing cattle, and because of asymmetrical competition between mammalian and insect herbivores.
... However, ubiquitous arthropod richness in vineyards were positively influenced by herbaceous vegetation in the inter-rows. Various studies have identified similar key variables for improving within-crop arthropod biodiversity, such as having herbaceous habitat for supporting arthropod predators (Shapira et al. 2017) and flowering plants for enhancing pollinator diversity (Carvalheiro et al. 2011), providing a range of niches for various arthropods (Morris 2000). As regards vineyards, there is a positive relationship between plant diversity and arthropod diversity and their ecosystem services in various areas [California: Sanguankeo and León (2011); South Africa: Gaigher and Samways (2010); Mediterranean: Winter et al. (2018)]. ...
Edges between adjacent biotopes may hinder or promote spillover of arthropods, influencing their distribution across landscapes. An understanding of spillover between natural and production areas enables management of edge effects for optimal biodiversity conservation. We assessed arthropod assemblages across vineyard-fynbos edges in the Cape Floristic Region of South Africa, where biodiversity-rich fynbos often borders vineyards. Species richness, assemblage composition, and compartmentalised beta-diversity (species turnover and nestedness) were assessed for three vegetation layers (ground level, lower vegetation, and upper vegetation) to determine bidirectional spillover. Species were also categorised according to biotope affiliation (crop-associated, fynbos-associated, or ubiquitous), based on habitat fidelity. We assessed how species richness of each biotope affiliation was influenced by environmental and management variables. Our main interest was biotope-specific variables which may enhance or impede spillover by influencing arthropods affiliated with the opposite biotope. Arthropod species richness did not differ along vineyard-fynbos transects for ground and lower vegetation layers but was lower in the upper vineyard vegetation compared to fynbos. Arthropod assemblages were distinct between biotopes for upper and lower vegetation but were similar on the soil surface and showed lower nestedness differences, indicating greater spillover by ground-level arthropods. In vineyards, no variables influenced fynbos-associated species, although herbaceous vegetation cover promoted ubiquitous arthropod species richness. Spillover between the biotopes was limited, and no drivers could be identified that promote spillover into vineyards, yet both biotopes supported diverse and distinct arthropod assemblages. Therefore, conservation of natural fynbos patches alongside sensitively managed vineyards is feasible for harmonising biodiversity conservation and viticulture.
... On the basis of the results, it was confirmed that continuous management (mowing) stabilizes the vegetation of grasslands, while ceasing can lead to the spreading of arboreal species and shrub, which, as a result, decreases biodiversity, as well. Thus, small-scale disturbances are necessary because these interventions can have a positive impact on species diversity [49,75]. Their setting back of competitor species helps propagules to spread, granting the continuity of ecosystem services [51,52,54], and meadows and wood pastures are, thus, among the most diverse habitats of Central Europe [58,92]. ...
The European temperate forest zone has great importance, in terms of maintaining the habitats of not only forests but also anthropogenous grasslands, which were formed as a result of habitat reconstruction. These habitats have great importance, by means of nature conservation, landscape use, economy, and forest and grassland use. The mosaic-like habitat complexes that consist of these grasslands and forest patches help to increase biodiversity and supply the habitat for forest game. In this survey, changes in the vegetation of the temperate forests (Fagetum) of the Mátra Mountains of Hungary were investigated after reconstruction. In 2012, shrub cutting was carried out in the area of Parádóhuta, and then three different management methods (abandoning, mowing, and grazing) were utilized. Our goals were the following: to perform a vegetation survey of the sample areas (i); surveying the natural regeneration of the grassland and analyzing its biodiversity, nature conservation, and economical value (ii); and analyzing the vegetation in terms of nature conservation and valuing its life form spectrum, economy values, and livestock-feeding ability (iii). According to our results, systematic mowing and a less-intensive grazing had a significantly positive effect on biodiversity and the coverage of species, thus increasing the naturalness of the studied grassland habitats, while wild game were able to act as ecological engineers.
... The concept of mimicking grazing behaviour of native wildlife in the holistic management approach is clearly rejected by this study: grass and ground-dwelling beetle species and assemblages differed significantly between holistic livestock and wildlife management. Morris (2000) highlighted the complexity of the interactions of arthropods with different types of grazing management. He showed that there is a requirement to determine the effects on arthropods of different grazing types, but broken Content courtesy of Springer Nature, terms of use apply. ...
Savannahs are often branded by livestock grazing with resulting land degradation. Holistic management of livestock was proposed to contribute to biodiversity conservation by simulating native wildlife grazing behaviour. This study attempts the comparison of the impact of a holistic management regime to a wildlife grazing management regime on grass and ground-dwelling beetle species diversity on neighboring farms in Namibian rangeland. Results show that the response of biodiversity in species richness and composition to holistic management of livestock differs substantially from wildlife grazing with a positive impact. From a total of 39 identified species of ground-dwelling beetles (Coleoptera: Tenebrionidae, Carabidae) from 29 genera, eight species were found to be indicators for holistic management of livestock and three were found to be indicators for wildlife grazed rangeland. Observations suggest that holistic management of livestock may contribute to biodiversity conservation, but the differential effect of grazing management on species assemblages suggests that livestock grazing cannot replace native wildlife herbivory.
Implications for insect conservation
An adaptive management strategy such as holistic management used in this study shows the potential to support high beetle biodiversity. Holistic management of livestock thus aspects in favour for a sustainable form of grazing management for insect conservation even though it does not functionally replace grazing by native wildlife.
... On the other hand, lower vegetation is not detrimental to all arthropods. For example, visual hunter arthropods may benefit from reduced vegetation (Morris, 2000), and it may also be beneficial for species that prefer warmer and drier microclimates (Zhu et al., 2020). In the present study, some steppe-associated species were also able to colonise and use the grazed meadow vegetation in large numbers. ...
... Biogenic habitats such as forests, grasslands, mangroves, seagrasses, and reefs are inhabited by a wide variety of resident organisms (Robinson & Holmes 1982;Morris 2000;Beck et al. 2001). These habitats provide substrate for settlement, decrease predation rates, and promote growth of resident species (Rausher 1979;Hixon 1998;Knutson et al. 2006). ...
Within estuarine and coastal ecosystems globally, extensive habitat degradation and loss threaten critical ecosystem functions and necessitate widescale restoration efforts. There is abundant evidence that ecological processes and species interactions can vary with habitat characteristics, which has important implications for the design and implementation of restoration efforts aimed at enhancing specific ecosystem functions and services. We conducted an experiment examining how habitat characteristics (presence; edge vs. interior) influence the communities of resident fish and mobile invertebrates on restored oyster (Crassostrea virginica) reefs. Similar to previous studies, we found that restored reefs altered community composition and augmented total abundance and biomass relative to unstructured sand habitat. Community composition and biomass also differed between the edge and interior of individual reefs as a result of species‐specific patterns over small spatial scales. These patterns were only weakly linked to oyster density, suggesting that other factors that vary between edge and interior (e.g., predator access or species interactions) are likely more important for community structure on oyster reefs. Fine‐scale information on resident species’ use of oyster reefs will help facilitate restoration by allowing decision makers to optimize the amount of edge vs. interior habitat. To improve the prediction of faunal use and benefits from habitat restoration, we recommend investigations into the mechanisms shaping edge and interior preferences on oyster reefs. This article is protected by copyright. All rights reserved.
... Such alterations in management can have different effects on vascular plant species composition and structure and consequently on associated taxa (Catorci et al. 2014;Littlewood et al. 2012;Lyons et al. 2018;van Klink et al. 2015;Watts et al. 2019). Grazing gradually removes biomass through the growing season which, together with deposition of dung and trampling, promotes structural heterogeneity in the sward (Rook et al. 2004;Tälle et al. 2016), providing greater potential for niche availability (Dennis et al. 1998;Morris, 2000). Owing to the contrasting responses of individual species and taxa to different management, monitoring of biodiversity beyond those targeted by changes in management is vitally important. ...
Calcareous grasslands, valued for their high species richness and diversity, are a European nature conservation priority. Their plagioclimax nature means that appropriate management is vitally important for their survival. This is usually aimed at conserving characteristic vascular plants, with less charismatic groups typically overlooked when implementing management. Consequently, evidence of impacts of contrasting management practices on a range of taxonomic groups is lacking. One such group are bryophytes which are often abundant in grasslands, contributing a substantial amount to overall plant diversity as well as being important for ecosystem processes such as carbon and nitrogen cycling. This study investigates aspects of bryophyte diversity in internationally rare upland calcareous grasslands subjected to conservation grazing which aims to conserve characteristic vascular plant communities versus those subjected to decade long cessation of grazing which are managed to promote increased structural heterogeneity across the landscape. Sampling across the range of management treatments was undertaken in June–July 2013 and 2014 where per cent cover of bryophytes was recorded in 0.5 m × 0.5 m quadrats along with sward height. Bryophyte abundance was greater in grazed grasslands than ungrazed grasslands, though there was no difference in species richness, diversity or the proportion of life history strategies between the management types. Hence the non-target group is not adversely affected by the management regime. The rarity of ungrazed calcareous grasslands in the uplands, coupled with their importance for various taxa warrants the continuation of this management practice.
Grasslands are among the most utilised habitat types for livestock production and the least protected ecosystems globally. Livestock grazing alters the abiotic and biotic features of a landscape and influences vegetation structure. In turn, these vegetation structural changes can adversely impact native animals that use these habitats, including reptiles. The endangered pygmy bluetongue lizard ( Tiliqua adelaidensis ) exclusively inhabits livestock‐grazed grasslands in South Australia. Using a before/after, control/impact design, we investigated the effects of short‐term grazing exclusion on vegetation structure and lizard abundance across two sites with natural vegetation and climate variation. We found vegetation structure differed between the two sites in “before” and “after” data but did not detect any effect of grazing treatment. We detected a negative association of lizard abundance with tussock cover in “before” data and a negative association with bare ground in the “after” data at the more arid site (Peterborough), although there was no significant overall grazing exclusion effect on lizard abundance at either site. Our survey techniques at a site scale may not have captured microhabitat‐scale changes that could have influenced pygmy bluetongue responses. This study indicates short‐term and small spatial scale grazing exclusion will have non‐significant effects on pygmy bluetongues. Sheep grazing management is an important component of pygmy bluetongue conservation, and we recommend further research to incorporate multiple spatial scales over a longer time prior to applying landscape management actions.
The greater one-horned rhino was a species in need of conservation in India and Nepal, where it is currently found in the wild. This rhino species has been threatened by well-organized groups of hunters, traders and smugglers, and the population in India and Nepal has suffered at times. Prolonged socio-political unrest around rhino range areas in India and Nepal has led to the total extirpation of rhino populations from the Laokhowa Wildlife Sanctuary in Assam, India in the 1980s and from Manas National Park in Assam in the late 1990s. Even Chitwan National Park and Bardia National Park suffered a decline in rhino population during the 2000s due to prolonged socio-political unrest in Nepal. However, due to proactive steps initiated by the Governments of India and Nepal, despite the threats posed to GOH rhinos by poachers and wildlife smugglers, the rhino population in India and Nepal has grown steadily to over 4000 individuals in the wild. Rhino range expansion through capture and reintroduction/translocation of rhinos in India and Nepal has further cemented rhino conservation efforts.
Species-rich grasslands of temperate Europe are threatened by the spread and increasing dominance of the rhizomatous grass Calamagrostis epigejos. Native hemiparasitic Rhinanthus species have been proposed as biocontrol to suppress C. epigejos, but experimental evidence is limited. We conducted a series of experiments at 21 grassland sites in Central Europe encroached by C. epigejos to test the effects of Rhinanthus on C. epigejos and on plant and arthropod communities and compare them to the effects of mowing applied once or twice a year. Rhinanthus suppressed Calamagrostis epigejos significantly more than mowing. Mowing frequency and Rhinanthus sowing had synergistic effects, leading to an average 75% reduction of C. epigejos biomass in Rhinanthus plots that were mown twice during the three-to four-year experimental period. The effect was more pronounced at sites in dry climates. Both Rhinanthus and mowing significantly increased plant diversity. Rhinanthus plots mown twice changed most rapidly towards the target grassland vegetation. The abundance and species richness of arachnids and Auchenorrhyncha were generally higher in abandoned plots than in plots with active management. Rhinanthus plots harboured fewer grass-feeding insects but more forb-associated herbivorous Auchenorrhyncha and Heteroptera species and several heliophilous spiders.
Our experiment showed that Rhinanthus spp., in combination with mowing, is an efficient and widely applicable method to reverse the encroachment of C. epigejos into grasslands and restore the diversity of infested plant communities. Active management measures also trigger a species turnover of arthropod communities, reflecting changes in grassland vegetation and arthropod guild species pools.
The extensive loss of carbon-rich, species-rich grasslands to agriculture and development has had detrimental impacts on wildflower abundance and diversity. Therefore, conversion of verges, lawns, and fields into wildflower meadows (WFMs) has gained prominence in recent years. However, a frequent recommendation for WFM establishment is to reduce soil fertility, raising concerns regarding the impact on carbon sequestration. To address the question of how WFM conversion might affect soil carbon retention, an experiment was conducted in Surrey, UK, converting grassland into WFM using different strategies: deturfing or scarifying, plus seed sowing. Measurements included earthworm abundance, live biomass, and microbial decomposition rates via a cotton strip assay (CSA), to provide insights into the initial phase of carbon sequestration: organic matter decomposition. The findings unveiled critical insights. In the short term, WFM conversion resulted in reduced earthworm populations relative to the control, especially when the conversion involved a high level of disturbance by removing turf. Conversely, mowing led to increased earthworm populations and accelerated CSA decomposition compared to the control. These findings suggest that the effects of disturbance and removal of biomass through deturfing or scarifying, and the energy supply provided by mowing and leaving the arisings, had more impact on the earthworm population and CSA decomposition than the increased diversity of the sown wildflowers. Successful WFM establishment can be achieved without turf removal, a practice that exerts adverse effects on soil life. These findings have broader implications for grassland resource management in the context of climate change mitigation through soil carbon storage.
kø b e n h av n s u n i v e r s i t e t i n s t i t u t f o r g e o v i d e n s k a b o g n at u r f o rva lt n i n g
Metodika zahrnuje všechny přírodní biotopy v České republice a věnuje se péči o ohrožené zástupce jak nočních, tak denních motýlů. Naopak všechny předchozí studie se omezovaly jen na stanoviště lesní nebo nelesní, případně motýly denní nebo noční.
Vedle důkladné znalosti relevantní literatury používá Metodika údaje o početnosti, stanovištní vazbě a nárocích na péči jednotlivých druhů získané z obrovských objemů dat, shromážděných pro denní motýly, a pro tzv. „malé čeledi“ motýlů nočních, v databázi „Mapování motýlů České republiky“. Na sběru dat se podílejí ročně stovky amatérů i profesionálů. S nejaktivnějšími z nich autoři konzultovali stanovištní nároky druhů, navíc lokality prakticky všech ohrožených druhů byly navštíveny v roce zpracování Metodiky a nároky ohrožených druhů upřesněny. Novátorská je analýza příčin ohrožení, konfrontující moderní poznatky o ohrožení denních a nočních motýlů, stejně jako přístup k jednotlivým typům stanovišť, které jsou pojímány spíš podle celkové fysiognomie vegetačního krytu než podle druhového složení. Vedle standardních zemědělských (seč, pastva) a lesnických (prosvětlování korunového patra, pěstování nízkých a středních lesů) doporučení obsahuje metodika i diskusi k perspektivním přístupům – radikálnějšímu mechanickému managementu a volné pastvě velkých herbivorů, která je slibnou alternativou pro velká a různorodá území.
Grassland management practices, such as grazing, strongly affects the biodiversity of grassland arthropods; increasing grazing intensity causes a general decline in species richness (Morris, 2000). One of the aims of the Rural Environment Protection Scheme (REPS) is to conserve and enhance biodiversity within Irish agricultural land (Feehan et al ., 2002). In order to determine the effectiveness of this aspect of REPS, one must compare the relative biodiversity of grassland under REPS with that of conventionally managed grassland. Aiming to determine whether species richness was higher in REPS-compatible compared with a standard system of management, we measured the species richness of grassland arthropods within two contrasting grassland treatments within an experimental study of suckler beef production.
This is an updated version of the best selling first edition, Ecological Census Techniques, with updating, some new chapters and authors. Almost all ecological and conservation work involves carrying out a census or survey. This practically focussed book describes how to plan a census, the practical details and shows with worked examples how to analyse the results. The first three chapters describe planning, sampling and the basic theory necessary for carrying out a census. In the subsequent chapters international experts describe the appropriate methods for counting plants, insects, fish, amphibians, reptiles, mammals and birds. As many censuses also relate the results to environmental variability, there is a chapter explaining the main methods. Finally, there is a list of the most common mistakes encountered when carrying out a census.
Auchenorrhynchan (leafhopper) faunas were monitored by vacuum sampling in each treatment of a controlled sheep grazing experiment on ex-arable land on limestone and in two nearby older calcicolous grasslands. The effects of foodplant architecture and species composition on leafhopper abundances and species composition (leafhopper "assemblies") were investigated by comparing the fauna with matched vegetation samples. The variability of assemblies over time was examined within three years of study and by comparison with older (1964-5) leafhopper studies of the same areas. Leafhopper assemblies were strongly affected by plant architecture as determined by grazing treatment. Plant species composition had relatively little effect, except that some species only found in older grasslands were restricted by their foodplants' distributions. Other species only found on old grasslands were probably restricted by their poor dispersal ability. Despite the deterministic effects of vegetation structure and composition, and leafhopper life-history traits, a substantial part of the variability in leafhopper assemblies could not be so explained. This variation occurred between younger and older grasslands sampled at the same time, within the study period from 1985-9, and between 1964-5 and the 1980s. Possible reasons for this variability in leafhopper composition are discussed.
Habitat structure can have a major influence on the organization of plant and animal communities (Bell et al. 1991). Specifically for herbivorous insects, several components of vegetation structure (vegetation texture and architectural complexity) are important contributors to variation in their abundance and diversity (Kareiva 1983; Denno and Roderick 1991). Vegetation texture includes several attributes: plant density (the distance between individuals of the same species), patch size (the geographical extent of the stand), and vegetation diversity (the frequency and identity of nonhost plant individuals (see Kareiva 1983; Denno and Roderick 1991). Also, individual host plants can vary in architectural complexity, which consists of two components: plant size (the spread of plant tissue through different positions in space) and plant part diversity (the number of different plant parts, both in form and persistence) (see South-wood et al. 1979; Lawton 1983; Denno and Roderick 1991). Together, these components of vegetation structure define the habitats of phytophagous insects. Variation in these host plant factors and interactions among them result in an array of habitat contingencies, each with different consequences for herbivore abundance and diversity.
Insects are the most diverse and abundant animals that share our world, and conservation initiatives are increasingly needed and being implemented globally, to safe guard the wealth of individual species. This book provides sufficient background information, illustrated by examples from many parts of the world, to enable more confident and efficient progress towards the conservation of these ecologically indispensable animals. Writing for graduate students, academic researchers and professionals, Tim New describes the major ingredients for insect species management and conservation, and how these may be integrated into effective practical management and recovery plans.
Insect herbivores can attack both the vegetative and reproductive structures of plants in a variety of ways such as defoliating, sap feeding, stem boring, leaf mining, gall forming, flower and seed feeding, and root feeding. This chapter discusses insect herbivory below ground. The organisms feeding on below-ground plant structures are either different species, or different stages in the life-history of species, to those feeding above ground. Below-ground herbivory is mainly found in the rodents, nematodes, molluscs, and insects. Of these groups, herbivory by nematodes is most widely documented. Nematodes exhibit very similar adaptations to insects for life in the soil and there are parallels among them in terms of their effects on plant physiology and growth. The paucity of ecological studies of below-ground herbivory most likely stems from difficulties with sampling and taxonomy of the causal agents and in assessing the extent of damage. Below-ground herbivory can influence the full complement of parameters affected by the feeding activities of herbivores above ground.
Describes and quantifies the following features of a secondary succession: 1) Changes in the habitat in terms of temporal and spatial dimensions and the relation of the former to the vertical axis of the habitat templet. 2) Successional patterns in the plants, their associated fauna and pathogens. 3) Adaptive strategies of the organisms characteristic of different stages in succession and an assessment of whether they follow a consistent pattern. Results are used from intensive field study of the characters and attributes of the macro-organisms (mainly green plants and insects) of a secondary succession on sandy soil at Silwood Park, Berkshire. -from Authors
This chapter reviews the ecology of fire in grasslands. It describes several generalizations such as environmental alterations, effects on species of plants, effects on vegetation, and associated animals. The grassland essentially includes any herb-dominated vegetation, herb dominated layers of savanna or open forests. Lightning is considered a universal natural cause of vegetation fires. A wide variety of other non-anthropeic causes of fire include volcanic eruptions, spontaneous combustion, and the occurrence of sparks when boulders roll down a slope. It is noted that these natural fires have been occurring from the earliest appearance of land vegetation. Their effect is to injure a plant community to a greater or lesser degree, after which the community escapes similar disturbance for sufficient time to allow a restoration of its former structure and composition. Grass fires are characterized by a rather narrow zone of flames advancing across a finely divided and homogeneously dispersed fuel. The fine texture of fuel makes it more sensitive to weather change than is true of woody aerial stems.
Pitfall trapping is reviewed as a sampling method for Carabidae. Catches are determined primarily by the size of the population at risk and the level of locomotor activity but species may show differential susceptibility to trapping according to size, behaviour, and the strata in which they are active in the ground vegetation. Catches of a single species may vary in different types of ground cover depending on the resistance they present to horizontal movement. These observations severely restrict the number of cases in which it is permissible to make quantitative comparisons between the catches of different pitfall traps.
1. Samples of turves from grazed and ungrazed chalk grassland at the Barton Hills, Bedfordshire were taken at about 26-day intervals over a period of 1 year, 1966-67, and the invertebrate animals extracted from them by heat treatment in Berlese funnels. 2. 3.7 times as many animals of the groups recorded were extracted from ungrazed grassland as from grazed. Most groups were recorded at higher density on the ungrazed grassland, and only a very few were more numerous on the grazed land. 3. The occurrence of the animals is discussed in relation to the management of chalk grassland nature reserves, rotational grazing regimes being recommended to maintain and increase diversity of the invertebrate fauna. 4. The results are compared with those obtained from a similar study made at Silwood Park, Berkshire, and discussed in relation to the type of grassland studied, the different treatments applied, and the different methods of recording.
(1) The increases in numbers of Auchenorhyncha following cutting of an Arrhenatherum grassland were recorded in a field experiment at Castor Hanglands NNR. Management by cutting in May, July, May and July, and Control (uncut) was replicated in four blocks of the four treatments and the fauna sampled regularly with a vacuum net from 1973 to 1975. (2) Six species increased in abundance on at least one of the treatments, and the response, not statistically significant, of two other species is examined. (3) Neophilaenus campestris, Euscelis incisus and Macrosteles laevis responded more to the single cut in July than to the double cut in May and July. Possible reasons for this are discussed. (4) Adarrus ocellaris increased clearly and progressively to cutting in July and appeared to become slightly more numerous by the end of the experiment on the grassland cut in both May and July rather than on that cut in July only. (5) The proportion of numbers of Paluda adumbrata recorded on the plots cut in May increased significantly over the controls from 1973 to 1975. Although few Psammotettix confinis were recorded, none at all occurred on the uncut grassland. Macrosteles sexnotatus and Recilia coronifera may also have increased following cutting. (6) The responses of the species are considered in relation to their life-histories and overwintering stages. Not every species is double-brooded and the multi-brooded Zyginidia scutellaris does not clearly increase in numbers following management. (7) The data are discussed together with other results from the experiment in relation to the management of grassland for nature conservation. Management options for nature reserves are considered. Some comparisons and contrasts are drawn with other types of grassland management in achieving stated objectives.
(1) Samples of Heteroptera and Auchenorhyncha were taken from replicated plots grazed by sheep in spring, summer, autumn and winter and from ungrazed areas of chalk grassland at Aston Rowant National Nature Reserve in August 1968 and from May 1969 to August 1971. (2) Thirty-five species of Heteroptera and forty-nine of Auchenorhyncha were recorded. There was no marked aggregation of individuals on any plot. (3) Fewer larvae of both groups were taken in July on the plots grazed in spring compared with the others. (4) Numbers of both groups, and the numbers of species represented, tended to be higher on the autumn- and winter-grazed plots than on those managed in spring and summer. The ungrazed grassland supported greater numbers of individuals and more species than the managed plots. (5) Species diversity of the Auchenorhyncha samples did not differ markedly between treatments, but was greater than expected on the grazed plots. (6) The results are discussed in relation to the practical management of chalk grassland nature reserves. Autumn or winter grazing is preferred to spring or summer grazing when other considerations permit. Annual grazing is inferior to rotational grazing for maintenance of species richness of Hemiptera.
1. A description and vegetation analysis is given for a small area of limestone grassland by Wytham Wood, Berkshire. Three sampling areas are distinguished whose spider fauna was studied: (1) a Brachypodium pinnatum sward; (2) an area consisting mainly of Festuca rubra; and (3) a sparse and diverse vegetation on loose Coral Rag limestone. 2. Collecting and sampling methods are described including a platform temperature-gradient apparatus designed to extract the spider fauna from vegetation quadrat samples. 3. The dense Festuca turf supported more spiders (up to 841.9/m2) than Brachypodium, and both recorded higher population densities than the more varied vegetation on the Coral Rag limestone. The most uniform vegetation (Brachypodium) recorded the lowest mean number of species; the highest number was recorded on the Coral Rag where floristic diversity was greatest. 4. The proportion of adults in the spider population was never more than 48% during the year, being highest in the winter and lowest in late summer (
1. The beetle fauna of grass tussocks in Silwood Park, Berkshire, was studied for 3 years. Both species and individuals were most numerous in winter. Most of the species were temporary inhabitants which occurred in small numbers, but a few, which were all either predatory, saprophagous or mycetophagous, were common. 2. Similar numbers of individuals and species of beetles were found in tussocks of Dactylis glomerata L. and Deschampsia caespitosa (L.), but Deschampsia contained exclusive species associated with the marshy habitat in which it chiefly occurred, as well as some species which were more common in Dactylis. 3. The number of genera of beetles found in Dactylis tussocks was similar to that caught in pitfall traps between the tussocks, but the common species in each were different. The commonest species in pitfalls were large predatory Carabidae, which were found only very occasionally in tussocks. 4. The density of beetles was higher in tussocks than outside, but since the tussocks covered only a small proportion of the area studied, they contained less than half its total beetle population, even in winter. 5. The biology of four common beetles inhabiting tussocks was studied. These were the staphylinids Stenus clavicornis (Scop.) and S. impressus Germ., and the carabids Dromius melanocephalus Dej. and D. linearis (Ol.). 6. In view of the differences between these species in the details of their associations with the tussocks, the need for a detailed classification of microhabitats is stressed, and a definition of microhabitat is proposed.
(1) Samples of the Auchenorhyncha of ungrazed exclosures and grazed control plots at the Barton Hills, Bedfordshire, were taken in summer 1967 and April 1968 to March 1969. (2) Forty-five species were recorded, of which fifteen were in small numbers, six showed no consistent pattern of occurrence related to management, two occurred more frequently on the grazed grassland and twenty-two were more numerous in the exclosures. Larvae were taken in greater numbers in the ungrazed grassland. (3) Marked increases in numbers in the exclosures from 1967 to 1968 were recorded for several species. (4) The relevance of measurements of diversity to conservation is discussed and the mean diversity of the leafhopper samples from the grazed and ungrazed plots compared. In both cases diversity increases during the summer to reach a maximum in late summer or early autumn. Mean diversity in the exclosures is greater than that on the grazed land at all times of the year. (5) The samples are compared with similar ones taken by Whittaker (1969) at Wytham, Berkshire, in relation to diversity and habitat preferences of the species. (6) The relevance of the results to the management of grassland for conservation is discussed. Some features of the measurement of diversity and its use in management research are considered.
(1) Adult Heteroptera were sampled regularly for 3 years, 1973-75, from experimental plots of Arrhenatherum-dominated calcareous grassland at Castor Hanglands N.N.R., Cambridgeshire. The experiment, in four replicates of four randomized block treatments, compared grassland cut in May (M), cut in July (J) and cut in both months (B), with untreated grassland (C). (2) Eighteen species were sufficiently abundant for statistical analysis. The data were pooled for three periods of the year: before the May cut (January to May), between cuts (May to July) and after the July cut (July to December). Fourteen species showed statistically significant effects of the cutting treatments in at least one period of the year; only once were numbers greater on a treatment than on the controls: in 1974, before the May cut, there were significantly more (P
1. Samples of Auchenorrhyncha were collected from fertilized plots between April 1978 and November 1979. 2. Twenty-nine species were recorded of which twenty-six probably breed regularly on the experimental area. 3. NPK fertilizer addition reduced leafhopper species diversity by disproportionately increasing the total number of individuals which effectively reduced the equitability index. 4. Delphacids were more abundant on plots receiving nitrogen fertilizer whereas cicadellids were more abundant on control (unfertilized) areas. 5. The major effect of nitrogen addition was to increase the food quality and the living area (plant architecture) available to leafhoppers. Both increased food quality and increased living area were beneficial to the leafhopper complex allowing the community to rapidly increase in numbers (i.e. the total captured in 1978 was 4122 whilst in 1979 the total captured was 17 964). 6. Leafhoppers were more abundant on plots with a 'preferred' leaf nitrogen level. Adult aggregation and female reproductive success were greater at the 'preferred' leaf nitrogen level.
(1) The Auchenorhyncha faunas of two contrasting types of grasslands seeded on chalk at Royston, Herts., were compared with those from a range of semi-natural and agricultural grasslands. (2) Among intensively studied sites, the Royston fauna was most similar to that of Castor Hanglands, on oolitic limestone grassland, and less closely related to those of three established chalk grassland sites. The similarity of the Royston and Castor Hanglands faunas lay mainly in the predominance of Arthaldeus pascuellus at both sites. On the established chalk grassland sites other species, particularly Turrutus socialis, predominated. (3) The species richness of the Royston fauna was not markedly lower than the richness of established sites, but resident species were fewer. All sites had similar numbers of multi-and bivoltine breeding species, but significantly fewer univoltine species bred at Royston. (4) Comparisons of annual totals of Auchenorhyncha recorded showed grouping strictly by site. (5) The Royston fauna was significantly richer than that of ryegrass leys on neutral soil, but not richer than the fauna of Park Grass, Rothamsted, though more individuals were recorded at Royston. (6) The Royston fauna was similar to the faunas of flood meadow grassland and 8-year-old seeded grassland on calcareous boulder clay in Cambridgeshire, particularly in the predominance of A. pascuellus. (7) An extensive survey of calcareous grassland sites for the Nature Conservation Review revealed few sites with faunas similar to that of Royston, mainly because A. pascuellus was not abundant on these sites. Sites surveyed more recently in Yorkshire and the East Midlands were similar to Royston, with A. pascuellus abundant on many of them. (8) The results are discussed in relation to the establishment of grasslands for wildlife conservation. Interactions with plant species composition, soil type, availability of nitrogen, and management are considered.
Niche and habitat differentiation are studied in seven sap-feeding insects (mostly leafhoppers and planthoppers) that inhabit the salt marsh grass Spartina patens. The microhabitat niche dimension is well partitioned. Four species of sap-feeders occur primarily in the upper stratum of the grass system, while three others are abundant in and beneath the lower thatch layer. Conversely, the seasonal niche dimension is poorly partitioned and most species show similar phenologies. The elevational habitat dimension is also poorly partitioned where most of the sap-feeders occur most abundantly on patches of grass within 10 cm of mean high water level. There are sufficient differences in resource utilization along niche and habitat dimensions as well as body size to explain the coexistence of all sap-feeders but two. The niches and body sizes of Amplicephalus simplex and Aphelonema simplex are very similar. One of these species, the leafhopper, Am. simplex, is the only species that fully retains the ability to fly. Populations of the other seven species are composed mostly of flightless brachypterous wing-morphs. It is hypothesized that Am. simplex is able to coexist in the guild because it is able to efficiently colonize relatively empty (competitor-free) patches of grass created by the catastrophic effects of storm tides.
(1) The effects of cutting calcareous grassland on its invertebrate fauna were examined in an experiment on Arrhenatherum-dominated grassland. Four treatments, cutting in May, in July, in both May and July and control (untreated) were applied annually to four randomized blocks of plots, each of which was sampled regularly with a vacuum insect net. Adult Hemiptera (Heteroptera and Auchenorhyncha) were identified to species and the effects of cutting on their numbers, abundance and diversity determined. (2) Simpson's and Brillouin's indices of species-diversity were preferred, for statistical and practical reasons, and to maintain continuity with previous work. Simpson's index proved to be rather insensitive to changes brought about by cutting. (3) Cutting in May slightly reduced the abundance and diversity of Heteroptera and the effects were short-lived. The effects on the abundance and species-richness of Auchenorhyncha were more marked and more persistent but diversity was scarcely reduced. Abundance, richness and diversity of both groups were consistently reduced by cutting in July. The effects on Heteroptera persisted until about January but those on Auchenorhyncha until shortly before the May cut. There was little difference between the effects of cutting in both May and July and cutting in July only, and generally the treatments grouped themselves into the two pairs May + Control and July + Both. (4) The results show that cutting in May only can maintain a high richness and diversity of Hemiptera on areas of grassland, including nature reserves, where management is necessary or imposed. Rotational management by cutting is advocated as a system of managing grassland nature reserves and is easier to establish than rotational grazing.
1. The numbers of some phytophagous insects were recorded in exclosures and on grazed plots measuring 40 x 25 m on an area of intensively grazed chalk grassland at the Barton Hills, Bedfordshire; in 1965 and 1966. 2. Populations of the weevils Apion loti and Miarus campanulae increased markedly in the exclosures in response to increased numbers of fruits of Lotus corniculatus and Campanula rotundifolia, the respective larval foodplants. 3. Production of Miarus campanulae in the exclosures in 1966 was estimated at 5-8 weevils/m2 of grassland. 4. Numbers of adult Neophilaenus exclamationis taken in a sweepnet were always higher on the ungrazed plots, but N. campestris, although taken more frequently in the exclosures at the beginning of its season, was recorded in larger numbers on the grazed plots later in the year. 5. Greater numbers of both larvae and adults of Leptopterna ferrugata were taken in the exclosures by sweeping in 1966. 6. More bumblebees visited flowers in the exclosures than on the grazed plots. 7. More Chorthippus parallelus were taken in the exclosures than on the grazed plots, but the reverse was true of C. brunneus. 8. These results are discussed in relation to the management of chalk grassland nature reserves. It is concluded that rotational grazing is likely to be a successful method of maintaining the grazed and ungrazed grassland biotopes in reserves and of conserving the characteristic faunas of both.
Coleoptera were sampled from plots in 4 replicates of 4 cutting treatments: May, July, both May and July (referred to as Both), and Control, established on oolitic limestone grassland dominated by Arrhenatherum elatius. Significant differences were recorded in the number of species represented (S), diversity (D, Brillouin) and evenness (E, Brillouin) of the fauna summed over the year; values were higher on the control plots and, though less clearly, on the July plots. D and E were greatly affected by the numbers of the small staphylinid Amischa analis, which was especially abundant on the May and Both plots. Significantly more species and individuals of predacious and saprophagous families were recorded on Control plots and, though less clearly, on May plots. No significant differences were recorded for phytophagous groups. Significant differences between treatments for S and D were recorded for some sampling periods, particularly in August after application of all treatments, but there were no differences in the abundance of individuals. Little similarity between the effects of the May and Control treatments, such as occurred for Hemiptera, was found in Coleoptera. This was partly attributed to a lack of vertical stratification of the beetle fauna in grassland. The results are discussed in relation to the management of nature reserves and the achievement of apparently conflicting objectives in conservation management. Rotational management offers a relatively simple means of doing this.-from Authors
(1) Hemiptera were sampled from two contrasting grasslands sown in April 1973 on a chalk soil which had previously grown cereals. Four replicates of the treatments were arranged in a randomized block design. Pitfall traps were used for 4 months after sowing, and vacuum net sampling late in 1973 and throughout 1974 and 1975. (2) The first colonists included typical opportunistic leafhoppers, seventeen species being recorded in 1973. The Heteroptera were varied and included many species not characteristic of calcareous grassland. (3) The most abundant Heteroptera during the whole sampling period were Nabis ferus, Notostira elongata, Trigonotylus ruficornis and Lygus rugulipennis. The last species declined in abundance from 1973 to 1975 and is not a typical grassland species. (4) The most numerous Auchenorhyncha were Arthaldeus pascuellus, which accounted for nearly half the individuals recorded, Javesella pellucida, Psammotettix cephalotes, Cicadula persimilis and Zyginidia scutellaris. A. pascuellus, Javesella pellucida and three other species declined in abundance from 1974 to 1975. (5) Although fifty species of Auchenorhyncha and forty of Heteroptera were recorded, many occurred as single specimens and equitability of both faunas was low. More species of Auchenorhyncha were recorded in 1975 than in 1974 and diversity of the faunal samples was consistently higher. Similar trends were not noted in the Heteroptera. (6) The results are discussed with reference to the establishment and management of species-rich grasslands for nature conservation.
(1) The responses of Auchenorhyncha to management by cutting of calcareous, Arrhenatherum-dommated grassland were examined in a field experiment. Four replicates of each of four cutting treatments, in May (M), July (J), both May and July (B), and Control (C) (uncut), were sampled regularly with a vacuum net for 3 years (1973-75). (2) Twenty-three species showed a significant difference in their abundance between treatments, though not all were consistent in time. The method of analysis (Tukey's T) allowed multiple comparisons to be made. (3) Cutting in May reduced adult populations of few Auchenorhyncha, single-brooded species with an early summer emergence of adults being most affected. Most species were not significantly reduced on the May-cut plots compared with the controls, but some effects were observed on the most abundant species. (4) The July cut severely reduced numbers of most species. Differences between the effects of the single July cut and cutting in both May and July were few, but when they did occur the combination cut reduced numbers more. The effects recorded clearly grouped the treatments into the two pairs M + C and J + B for most species. (5) Effects of the May cut were generally short-lived. Those of the July cut persisted, often through the winter into spring. Most of the species which overwintered as adults were affected during the winter by the previous summer's cut. (6) Progressive declines were recorded in many species from 1973 to 1975. Although these occurred particularly on the plots cut in July, populations of some species also declined on the uncut grasslands. Possible reasons for this are suggested. (7) The interaction of the timing of treatment with the phenology of Auchenorhyncha explains many of the findings. Most species become adult in late summer (July-September) and are particularly affected by cutting in July Stratification of species in tall grass is an important factor in determining the fauna of grasslands. (8) The findings support earlier recommendations for the management of grassland nature reserves, but the positive responses of other species of Auchenorhyncha, not reported here, to cutting need also to be considered.
Land disturbed or destroyed by mining and similar activities is an inevitable part of civilization. We inherit a large area from the past and the destruction continues to the present. The product is destroyed soils and vegetation. The natural colonization provides an insight into natural processes of primary succession. Colonization is both deterministic and stochastic. Ecosystem development involves a large measure of facilitation. Many sites left to colonize naturally are of considerable ecological value. But natural colonization is slow and ecosystem development must usually be assisted. It is now relatively easy to treat most of the factors limiting development. However, these factors must be handled with ecological understanding. Nitrogen in particular has to be built up to total levels of at least 1000 kg ha-1. Soils may have unexpectedly high phosphorus binding capacities. Treatment of toxicities may involve a number of different strategies. It is relatively easy to reintroduce agricultural and forest tree species. Wild species are more difficult, yet if their reproductive biologies are properly understood they can be handled with ease and reliability. Most animals will return on their own, but recolonization is assisted by careful habitat reconstruction and some important species may sometimes require reintroduction. Despite the readiness with which some people promulgate pessimism, here is an environmental problem for which solutions are available and one to which ecologists have an important contribution to make.
Species richness of grassland Heteroptera at Royston, Hertfordshire, was low and few differences between treatments were observed. Significantly more plant bugs overwintered in the coarse grassland than in the fine, with consistent, significant differences between treatments for Notostira elongata and Nabis ferus. Auchenorhyncha were more abundant on the coarse grassland in 1974, but on the fine grassland in 1975. Species richness, equitability, and especially diversity, were higher on the coarse sward. The fauna of the coarse grassland tended to be more diverse at any one time, but cumulatively the fauna of the fine sward was slightly more diverse. Species predominant on the coarse grassland were Neophilaenus lineatus, Conosanus obsoletus, Mocydia crocea, Cicadula persimilis, Stenocranus minutus, Zyginidia scutellaris and Javesella pellucida (in the 2nd generation only). The last 4 species were abundant. Species predominant on the fine grassland were Deltocephalus pulicaris, Turrutus socialis, Euscelis incisus, Paluda adumbrata, Mocydiopsis attenuata, Dikraneura variata and Criomorphus albomarginatus. None of these species was abundant. Arthaldeus pascuellus was significantly more numerous on the coarse sward in summer 1974, but much more abundant on the fine sward in summer 1975. Mixtures of many grass species should be used to establish patches of grassland of variable structure and composition. -from Author
The importance of early-successional stages for the conservation of threatened butterflies of calcareous grassland, and reasons for their decline, are outlined.The opportunity to re-establish chalk on a site made available through construction of a motorway (the Bar End to Compton section of the M3, Hampshire) is described. The characteristics of the site are compared with present-day and historical conditions on the adjacent St Catherine's Hill Site of Special Scientific Interest.Details of proposals to modify the topography of the site by ecological engineering are given. This modification is based upon a detailed knowledge of the ecological requirements of a range of scarce butterfly species, microclimatic observations and an assessment of available resources for re-vegetating the site.The reason for the failure to implement the proposals are discussed. It is suggested that conservationists need to give greater emphasis to dynamic aspects of conservation and re-creation of early-successional communities.
Analyses of their habitats indicate that 18% of British butterfly species are restricted to the earliest seral stages of ecosystems, whereas the same species occupy later seral stages in central Europe, where spring and summer temperatures are warmer. The microclimates of their British habitats are exceptionally warm, compensating for the cooler climate. Most of these British habitats are also ephemeral, and have long depended on man for their creation and regeneration This poses the question of where these species lived before man created their habitats, roughly 6000 BP, I suggest that they are relics from a period when British summers were warmer than today, and that they avoided extinction when the climate cooled by moving into warm refugia created by prehistoric man within three types of ecosystem If summer temperatures become warmer, these species should return to later seral stages that are commoner and less dependent on man.
Of the six species of wild geese which winter in Britain in large numbers, five are increasing in number and cause agricultural damage on a local scale. The management of grassland as feeding areas, to attract geese off agricultural land, is widely acknowledged as a potential solution to the problem. Similarly, grassland refuges are commonly established as a means of conserving rare or localised species of geese in Britain. Both require precise management guidelines if grassland areas are to be managed effectively. This paper summarises the information available concerning the management of grassland for wild geese wintering in Britain. We consider criteria for the location of feeding areas and the size of feeding areas required to support given populations of geese on local and national scales. Sward management is considered in terms of species composition and height, the value of fertiliser application and the relative merits of management through livestock grazing or mechanical cutting of grass pastures over the summer. The greatest potential for maximising goose numbers within an area appears to be through manipulation of sward height and fertiliser application. We discuss potential conflicts between managing grassland for geese and for other species and highlight possible directions for future research.
The effects of cutting in May or July, and in both May and July, on the invertebrate fauna of a calcareous grassland were examined from 1972 to 1975 in a field experiment of four replicates of four treatments laid out as randomised blocks. Coleoptera were sampled at five different periods in one year by extracting standard turves in Berlese-type funnels. Additional species were taken by vacuum netting. Two hundred and seventeen species were recorded, with Staphylinidae the predominant family in numbers of species and individuals. Carabidae, Chrysomelidae and Curculionidae were also well represented. The effects of cutting were varied. Significant deleterious effects were recorded for 17 species. Twelve species responded positively to one or more of the cutting treatments. Cutting tended to benefit phytophagous species. Saprophagous, detritivorous, fungivorous and some predacious species were favoured by lack of management. The implications for management of nature reserves are discussed. The importance of both long and short grass in maintaining species richness, and the timing and frequency of management, are emphasised. Rotational management is recommended as a means of achieving management aims.
Samples of Hemiptera were taken in September 1972, from areas of carboniferous limestone grassland which were burnt in April and May 1972, and from adjacent unburnt areas. Significantly larger numbers of species, of both Heteroptera and Auchenorhyncha, were recorded from the unburnt areas, and the species-diversity of the samples was significantly greater. The effects of burning on individual species are considered in relation to their biology and the effects of other kinds of management. The results are discussed in relation to the management of grassland for the conservation of wildlife, and a short review of the effects of burning on populations of invertebrate animals is made.
1. Native species are translocated for conservation, commercial, amenity and research purposes. These activities are related, and need to be considered and planned in terms of their effects on biodiversity. 2. Procedures for assessing, implementing and regulating translocations have, however, been subject to largely uncoordinated development; recommendations or guidelines being produced separately for each area of expertise. There is a need to pull together the profuse information concerning specific translocations in order to present a broad approach to the general problems and concerns. 3. Here, the extent and nature of translocations of native species within the UK are reviewed, and recommendations for policy and legislation are made in the context of those currently in use in the UK. The recommendations include the following: (i) improvement of the ways in which relevant information is disseminated; (ii) ease of implementation should be a prime consideration; and (iii) formation of new policy and guidelines should include all UK and international organizations involved in carrying out, advising on, or licensing translocations.
Leafhoppers were sampled from 13 piots receiving different fertiliser treatments in the classical Park Grass Experiment, Rothamsted. Samples were taken, on five summer dates in both 1977 and 1978, from near-neutral and more acid subplots, maintained by differential liming. Of 47 species recorded, Psammotettix confinis was the most abundant. The fauna was characterised by species of acidic, not calcareous, grassland. Few univoltine species were recorded.Species richness was greater on the near-neutral subplots, on which four species were significantly more numerous. Psammotettix confinis was more abundant on the more acid subplots. More species were taken from the plots receiving no nitrogen fertiliser than from fertilised plots, and the abundance of eight species was significantly correlated with the amounts applied. Positive and negative correlations were recorded, with most effects on either the near-neutral or more acid subplots, but not both.The numbers of the two species were negatively correlated with application of minerals. Abundance of total Auchenorhyncha and of Psammotettix confinis was negatively correlated with yield of hay. The faunas of the neutral subplots were less similar in both 1977 and 1978 than those of the more acidic subplots. Yearly differences in abundance of some species are tentatively ascribed to the greater summer rainfall in 1978 compared with 1977.The mediation of treatment through vegetational changes is considered. The distribution and abundance of some species correlated with increased abundance of their food plants through acidification of the grassland by ammonium sulphate. The ecology of species associated with Holcus lanatus is discussed.A principal components analysis was made using the covariance matrix of 1n (n+1) abundances. The first two axes broadly expressed amounts of nitrogen applied and pH, and accounted for 29% and 21% of the total variation, respectively.The results are compared with other zoological work on Park Grass. The responses of Auchnorhyncha are clear, despite their potential for movement between subplots.
Invertebrate communities were monitored in a controlled sheep grazing experiment on ex-arable land on limestone and in nearby older calcicolous grasslands Results for vacuum sampling of Heteroptera and herbivorous Coleoptera are presented and compared with the responses of spiders, leafhoppers and leaf-miners
Invertebrate groups differed in their responses to grazing and grassland age in terms of species diversity, abundance, variability over time and the development of a specific fauna on short turf Leaf-miner assemblies were most strongly determined by the effects of grazing on plant species composition, while spiders' responses could largely be explained by the effects of grazing on plant architecture Spider species simply accumulated over time, whilst leaf-miners were the most labile group Spiders, leaf-miners and leafhoppers all contained some common species restricted to old grasslands, whilst herbivorous Coleoptera and Heteroptera did not
No single group demonstrated the full range of invertebrate responses Spiders, leafhoppers and leaf-miners each showed useful features as “indicator groups'”, but more than one group should be chosen for study in the context of particular research projects
Heavily grazed assemblages were dominated by a group of Linyphiidae, also characteristic of disturbed land. Large web-spinners were most sensitive to grazing, preferring ungrazed controls because of their dependence on rigid plant structures. Only heavy grazing (in spring and autumn) produced a distinct assemblage. The dominant successional trend was a gradual accumulation of species, especially in ungrazed controls. Old grasslands contained many species, including some characteristic of calcareous grassland, which had failed to colonize the ex-arable field seven yr after abandonment. Most features of the assemblages could be explained by the effects of grazing on plant architecture. -from Authors
From 1973-1975 the effects of cutting on the invertebrates of Arrhenatherum-dominated grassland were studied. Reversion of the plots was studied from 1976-1978. Adult Hemiptera (Heteroptera and Auchenorhyncha) were identified and counted. The host dry summer of 1976 had effects which were assessed on control (C) plots which were not cut. In general, species of damp grasslands declined in abundance whereas those of dry, and of short, swards increased. Heteroptera increased progressively in abundance from 1976-1978 on the previously-managed plots. No differences between treatments were recorded in the abundance of individual species, or for N and S (total number of individuals and species, respectively), but the rates of increase from 1975-1978 were significantly different. The rates of increase in Auchenorhyncha N and S were similarly grouped, but the rate of increase in diversity was greater on every treatment than on the controls. Auchenorhyncha species displayed various responses to cessation of management.-from Authors
British colonies of Hesperia comma have declined to 49 populations, most of which were small. Adult H. comma proved to be very particular when egg-laying. They preferred small Festuca ovina plants that were largely surrounded by bare ground or scree, and which also grew in sheltered sunspots. Most F. ovina growing on most sites were rejected as unsuitable, and the adult population density of H. comma was correlated with how closely the sward approached the ideal structure for egg-laying. Most sites that had lost H. comma still contained abundant F. ovina, but were too overgrown to be suitable for breeding. Most extinctions of H. comma occurred during a 20-yr period, when many unfertilized downs in Britain became overgrown after rabbits Oryctolagus cuniculus were killed by myxomatosis. The habitat on several former sites has improved for H. comma since the late 1970s, due to a recovery by rabbits and some sheep stocking on abandoned downs. To date, H. comma has only spread to re-occupy sites that were within 4 km of existing colonies. Conservationists could dramatically improve the status of H. comma by making artificial introductions to unoccupied sites.-from Authors
The ecology of the declining butterfly Aricia agestis was studied in southern England by measuring oviposition preferences, and from population estimates and habitat analyses of colonies on seven sites. The adults live in small, predominantly closed populations, although movement is not as restricted as in most other lycaenid butterflies studied. Butterfly collectors pose little threat to this species; population size is instead restricted by the precise ecological requirements of the egg site, and hence the larval stage. A. agestis chooses 'lush', sheltered growths of the larval food plant, Helianthemum chamaecistus. The organic nitrogen content and mesophyll thickness of plants selected for oviposition on study sites were significantly higher than in randomly selected plants. Structural features of the foodplant and its surroundings were less important than for other lycaenids; although the presence of bare ground influenced oviposition, turf height - at least at the study sites did not. A survey of seven sites showed no correlation between the densities of A. agestis and H. chamaecistus, but there was a strong correlation between butterfly density and the number of the lush foodplants that were growing in the form chosen for oviposition. Priorities for the management of sites are suggested.
21 species of butterfly went extinct in Suffolk between 1850 and 1980, depite the food plants of all but 4 remaining common. Reviews the ecology of several British species.
Grass nutrient levels differed considerably between the grass species and with time.
Most species of leafhopper (Homoptera, Auchenorrhyncha) were present on all the grasses sampled but each grass had a different dominant leaf‐hopper fauna.
The leafhopper—plant association varied depending on the leafhopper species. Species that were strongly associated with one host were rare. Other more oligophagous species were associated with a particular nitrogen level in the grass. These species were found on grasses that had nitrogen concentrations within a narrow range. As the plant nitrogen levels altered (associated with flowering, seed setting, and senescence) leafhoppers switched onto other food plants that had a suitable nitrogen level. An intermediate group of leafhoppers showed little specificity and little association with plant nitrogen levels.