Article

Habitat diversity in forest plantations reduces infestations of the pine stem borer Dioryctria sylvestrella

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Abstract

Summary • The risk of pest damage in forest monocultures is a growing concern as the area of plantation forest expands world-wide and sustainable management is becoming a general goal. Numerous studies have demonstrated that pest insects are less abundant in more diverse agroecosystems, but limited experimental evidence exists for a similar relationship in forestry. Because plantation forests are usually mosaics of single-species stands, the aim of this study was to test the effect of forest diversity at a landscape level on pest insect infestations. • Within a stand of maritime pine, trees attacked by the stem borer Dioryctria sylvestrella showed no spatial aggregation and clusters of 66 trees proved to be an optimal sampling unit for determining overall percentage infestation. • The spatial distribution of stem borer infestation levels was examined in three maritime pine stands bordered by mixed-species stands of broad-leaved trees, and overall infestation levels compared between four such maritime pine stands and four other maritime pine stands of the same structure but far from any broad-leaved stands. • The percentage of trees infested was significantly lower in the pine stands bordered by broad-leaved stands than in the pine stands surrounded by other pine stands, and in the former, stem borer infestation showed a significant logistic increase with distance from the stand edge. This could be due to effects of resource concentration or natural enemy attack, both of which are discussed. • These results suggest that the conservation or restoration of non-productive mixed-species stands adjacent to intensively managed plantations is a useful preventive method for pest management in forest monocultures.

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... 27 out of 72 seedlings (37.5%) in all four 50% mixture and 11 out of 36 seedlings (30.6%) in the 25% mixture (25%Nauclea/25%Pericopsis/25%Terminalia/25%Tetrapleura) plots survived ( Fig. 4.2). These results agree with some studies which showed decreases in insect herbivory on tree species in mixtures than in monocultures (Jactel and Brockerhoff, 2007;Kaitaniemi et al., 2007;Bosu et al., 2006;Jactel et al., 2006;Riihimäki et al., 2005;Ofori et al., 2004;Jactel et al., 2002;Nichols et al., 1999;Su et al., 1996). Nichols et al., (1999) found significant reduction in the number of Psyllid galls two months after planting in mixtures of Milicia excelsa and Terminalia superba than in monoculture Milicia excelsa stands. ...
... Results from Vehviläinen et al., (2006) also showed no significant difference in herbivore between Silver birch and paired mixtures with Scots pine and Norway spruce at the end of the vegetation period. It is however in contrast to some other studies which reported significant herbivory reduction between monocultures and mixtures (Sobek et al., 2009;Jactel and Brokerhoff, 2007;Kaitanienen et al., 2007;Jactel et al., 2006;Jactel et al., 2002). Kaitanienen et al., (2007) found that a significantly lower proportion of sawfly larvae and eggs survived on pines grown in mixtures with birch as compared with monoculture stands in western Finland. ...
... Moreover despite the relatively decreased mortality in the 50% mixture, the 25% mixture consisting of (25%Nauclea/25%Pericopsis/25%Terminalia/25%Tetrapleura) had the least survival rate after 60 months (Fig. 4.3). This shows the importance of considering species diversity threshold in insect herbivory-diversity relationship and possible influence of other factors which can potentially act to influence the benefits of mixed species in reducing pest damages in Nauclea diderrichii and Pericopsis elata (Healy et al., 2008;Jactel et al., 2002;Maron, 1997). ...
... La morphologie différente de ces arbres de bordure, notamment en termes de circonférence, peut expliquer la plus forte abondance des attaques Dioryctria sylvestrella. Ceci a précédemment été démontré par Jactel et al. (2002) à partir de l'étude exhaustive de tous les arbres d'une parcelle, au sein du même massif et pour des niveaux d'infestations moyens similaires (15,2 % d'arbres attaqués). L'effet de l'exposition de la ressource est encore plus flagrant en ce qui concerne le défoliateur Thaumetopoea pityocampa, qui est connu d'après Demolin (1969) pour préférer les arbres isolés ou ceux dont la silhouette se détache sur fond clair. ...
... Cependant, cette richesse en habitat s'avère plus importante à proximité des ripyslves, les formations d'essences feuillues sont majoritairement concentrées le long des cours d'eau, qui sont par nature elles-mêmes structurées dans le paysage. Aussi, il est difficile d'attribuer ce résultat au seul effet de la diversité d'essence, comme dans le cas d'autres ravageurs endémiques à ce paysage (Jactel et al., 2002). Par ailleurs, on notera que ces métriques paysagères sont souvent inter-dépendentes et que le choix de la taille du voisinage considéré pour les calculées affectera notre perception des composantes du paysage et de leur organisation (Cushman et al., 2008 ;Rossi et van Halder, 2009). ...
... L'intensité de la réponse aux effets de bords s'est avérée spécifique à chaque type de dommages. Ainsi, le pourcentage d'arbres endommagés par la Pyrale du tronc était sensiblement plus élevé en lisière sans doute à cause d'une taille différente des arbres (notamment en termes de diamètre, Cf.Jactel et al. 2002). Dans le cas de la Processionnaire, la démarcation de la silhouette des arbres ainsi que l'effet de l'exposition de la canopée à un plus fort ensoleillement sont certainement les facteurs qui induisent une concentration des nids d'hiver environ 2,5 fois plus importante en bordure qu'à l'intérieur des peuplements(Cf. ...
... Particularmente, la infestación por barrenadores ha sido positivamente asociada con el diámetro del árbol hospedante (Zhang et al. 1993, Cabrera 1994, Díaz 1999, Reid & Robb 1999, Carrasco 2000, Manqui 2001, Jactel et al. 2002. Los posibles mecanismos causales detrás de este patrón son variados y se pueden agrupar en dos: ...
... En el primer grupo están las características químicas del hospedante. Se han encontrado asociaciones positivas entre el diámetro de los árboles hospedantes y la presencia de compuestos químicos atractivos para el insecto dañador (Jactel et al. 2002). Por otra parte, Lawton (1983) sugirió que árboles de mayor tamaño son más fáciles de descubrir por su apariencia que los más pequeños ("per se size hypothesis"). ...
Article
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Infestation pattern,; of xylophagous insects were evaluated in second growth stands of Nothofagus obliqua and Nothofagus dombeyi in Valdivia, Osorno and Llanquihue provinces of Chile. The analysis addressed two scales. First, at the individual level, diameter at breast height (DBH) and canopy class (CC) of the host tree were used as predictor traits of xylophagous damage. Second, at the stand level, variables such as total tree density, host density, species richness and cover (arboreal, shrubby, herbaceous and epiphytic strata) and their asociation with infestation average were considered. The infestation mean was 9.35 % for N. obliqua and 15.89 % for N. dombeyi. At individual level both DBH and CC were positively associated with damage presence. However, the best predictor of tree infestation was DBH in both N. dombeyi and N. obliqua, greater DBH increasing the probability to find all infested tree. At the stand level, no relationship was found between insect infestation and evaluated traits in N. obliqua. whereas N. dombeyi stands with high species richness in the shrubby sstratum and/or with higher total tree density and host density showed the lowest infestation levels.
... Particularmente, la infestación por barrenadores ha sido positivamente asociada con el diámetro del árbol hospedante (Zhang et al. 1993, Cabrera 1994, Díaz 1999, Reid & Robb 1999, Carrasco 2000, Manqui 2001, Jactel et al. 2002. Los posibles mecanismos causales detrás de este patrón son variados y se pueden agrupar en dos: ...
... En el primer grupo están las características químicas del hospedante. Se han encontrado asociaciones positivas entre el diámetro de los árboles hospedantes y la presencia de compuestos químicos atractivos para el insecto dañador (Jactel et al. 2002). Por otra parte, Lawton (1983) sugirió que árboles de mayor tamaño son más fáciles de descubrir por su apariencia que los más pequeños ("per se size hypothesis"). ...
Article
Full-text available
Infestation patterns of xylophagous insects were evaluated in second growth stands of Nothofagus obliqua and Nothofagus dombeyi in Valdivia, Osorno and Llanquihue provinces of Chile. The analysis addressed two scales. First, at the individual level, diameter at breast height (DBH) and canopy class (CC) of the host tree were used as predictor traits of xylophagous damage. Second, at the stand level, variables such as total tree density, host density, species richness and cover (arboreal, shrubby, herbaceous and epiphytic strata) and their asociation with infestation average were considered. The infestation mean was 9.35 % for N. obliqua and 15.89 % for N. dombeyi. At individual level both DBH and CC were positively associated with damage presence. However, the best predictor of tree infestation was DBH in both N. dombeyi and N. obliqua, greater DBH increasing the probability to find an infested tree. At the stand level, no relationship was found between insect infestation and evaluated traits in N. obliqua, whereas N. dombeyi stands with high species richness in the shrubby stratum and/or with higher total tree density and host density showed the lowest infestation levels
... Moreover, as these plantations experience frequent outbreaks of pest insects, a functional role of biodiversity in ecosystem resistance to pest insects is expected. Experimental evidence for decreasing pest insect infestations in pine plantations with decreasing distance from deciduous woodlands remaining within the forest mosaic was obtained for two important lepidopteran pests in the area, namely Dioryctria sylvestrella and Thaumetopoea pityocampa (Jactel et al., 2002). This study suggests that deciduous patches may act as refuges or complementary food sources for natural enemies at the landscape scale. ...
... These patches may act as refuges and source habitats for predatory birds and arthropods, at least for some of their habitat requirements, for example for foraging, breeding, or wintering (Estades & Temple, 1999;Magura, Ködöböcz & Tothmérész, 2001;Griffis-Kyle & Beier, 2003). However, a negative influence of the proximity of deciduous patches was also found for several openhabitat spiders and carabids, possibly because they may suffer higher bird predation (van Wilgenburg, Mazerolle & Hobson, 2001;Jactel et al., 2002). ...
Article
Nous avons réalisé une étude avec plusieurs taxa pour analyser la réponse d'assemblages d'espèces aux variables stationnelles et paysagères dans les forêts de plantations de pin maritime des Landes de Gascogne (sudouest de la France). Nous avons échantillonné simultanément les oiseaux nicheurs, les coléoptères carabiques et les araignées épigées dans un échantillon de 27 parcelles différant selon leur composition en espèces d'arbres, leur âge et leur structure verticale. La composition et la structure du paysage environnant ont été quantifiées dans un rayon de 500 m autour des parcelles. La réponse des espèces à une combinaison de 12 variables stationnelles et paysagères a été analysée par régression multiple pas à pas. La relation entre les assemblages d'oiseaux, de carabiques et d'araignées et les mêmes variables environnementales a été étudiée par une série d'analyses de co-inertie. La hauteur moyenne des arbres est la meilleure variable explicative pour tous les taxa à la fois au niveau de la richesse spécifique, de la composition des assemblages et de l'espèce. Les variables paysagères constituent des facteurs secondaires importants, en particulier la fragmentation du paysage, l'hétérogénéité spatiale et la forme et la distribution spatiale des îlots de feuillus dans le paysage environnant. La présence d'îlots de feuillus et l'hétérogénéité du paysage sont favorables aux oiseaux et aux araignées des habitats forestiers, mais ne favorisent pas les carabiques, sans doute en raison de la moindre capacité de dispersion des carabiques forestiers. Nomenclature: Hänggi, Stöckli & Nentwig, 1995; Coulon et al., 2000.
... Most forest plantations are established as monocultures, but there is growing recognition that mixed-species forests have advantages over monocultures (Nichols et al. 2006;Kelty 2006;Knoke et al. 2008), including increased standlevel productivity (Binkley 2003;Forrester et al. 2006b), increased individual tree growth rate (Piotto 2008;Wang et al. 2014), improved potential to restore degraded lands (Parrotta and Knowles 1999), and reduced risk of tree diseases and pest damage (Jactel et al. 2002). In addition, mixed tree plantations provide ecological services, including potential to sequester CO 2 (Epron et al. 2013;Forrester et al. 2006a). ...
... Converting monoculture forest plantations into mixedspecies forests has both ecological and economic benefits, for example higher productivity and potential to sequester atmospheric carbon (Jactel et al. 2002;Binkley 2003;Piotto 2008). We measured changes in C stocks after conversion from pure Chinese fir plantations into mixed-species stands and compared two different conversion methods for Chinese fir monocultures. ...
Article
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Mixed-species forests have potentially more benefits than monocultures particularly in terms of greater carbon sequestration. A 16-year-old Chinese fir (Cunninghamia lanceolata) monoculture in Zhejiang, China, was converted to a Chinese fir—broadleaved plantation by thinning from below (TFB) and crop tree release (CTR) methods coupled with planting of Chinese sweet gum (Liquidambar formosana) seedlings. Carbon pools in trees, snags, shrubs and herbs, seedlings, litterfall, forest floor, and mineral soil were measured for 5 years. The total tree biomass carbon increase in un-thinned control and CTR stands was approximately 15% higher than that in TFB. The average individual tree biomass C stock increased by 20.5% and 9.2% in CTR and TFB, respectively. Carbon flux through litterfall decreased after thinning but recovered, thereafter, to a level similar in the un-thinned control. Compared to the control, lower tree mortality and higher growth of seedlings in both converted stands resulted in no change in ecosystem C stocks. Carbon stocks in trees and seedlings increased more in CTR than in TFB stands, implying that CTR should be favored when converting pure plantations into mixed-species stands.
... Niemelä and Mattson (1996) suggested that diverse North American forest communities facilitate the establishment of European phytophagous insects by providing more potential hosts for invaders. Jactel et al. (2002) indicated that higher plant diversity may also impede invasion by non-native insects if it enhances mortality from natural enemies, observing that the percentage maritime pine (Pinus pinaster Aiton (Pinaceae)) colonised by pine stem borer (Dioryctria sylvestrella (Ratzeburg)) (Lepidoptera: Pyralidae) decreased as plant diversity increased because of higher parasitism rates. Also, high diversity of non-host plants may interfere with host location by insects, for example by masking host volatiles, and reducing host quality through interspecific resource competition (Zhang and Schlyter 2004;Jactel et al. 2011). ...
... Low-density ash stands were just as susceptible to EAB colonisation and ash mortality as highdensity ash stands, as also observed by Knight et al. (2013). This suggests that non-host trees do not hinder host location efforts by EAB, as observed for some other forest insects (Jactel et al. 2002), possibly because EAB is highly specialised on ash with well-developed chemosensory cues for locating hosts (Crook and Mastro 2010), even at low densities. ...
Article
Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a non-native, wood-boring beetle that has caused widespread mortality of ash (Fraxinus Linnaeus (Oleaceae)) in eastern North America. During 2004-2007, we determined whether forest community composition and structure of black (F. nigra Marshall), green (F. pennsylvanica Marshall), and white (F. americana Linnaeus) ash stands influenced their susceptibility to EAB invasion in southeast Michigan, United States of America. There was no relationship between EAB-induced ash decline or percentage mortality and any measure of community composition (tree species diversity, stand/ash density, total basal area, or relative dominance of ash). There was also no relationship between measures of EAB impact (density of EAB signs, ash decline rating, percentage ash mortality, or percentage infested ash) and forest attributes (ash/total stand density, basal area, ash importance, or stand diversity). Decline and mortality of black ash advanced more rapidly than that of white and green ash. Percentage mortality of ash increased from 51% to 93% during 2004-2007. Distance from the epicentre of the invasion was negatively correlated with ash mortality, but this relationship dissipated over time. Stand composition data suggests that ash will be replaced by Quercus Linnaeus (Fagaceae), Acer Linnaeus (Sapindaceae), and Tilia Linnaeus (Malvaceae); such vegetation changes will irreversibly alter the structure and function of these forests.
... However, among both the forester community and the general public, the belief that science can prevent and eliminate risks is still very prevalent, even if some foresters are beginning to depend more and more on nature to restore balance to ecosystems. Theses opinions can be found when interviewees expressed their interest in biodiversity (variable Biodiv) and in broadleaves (variable Intfeuil) as an efficient means of mitigating pest damage in maritime pine forests (Jactel et al. 2002). Foresters also have very different opinions about the benefits of deadwood conservation (variable IntBoisM) and slash harvesting in providing bioenergy (variable Remanent). ...
Article
Dead wood is a key element in forest biodiversity, which is used as one of the indicators for sustainable development of forests. A survey was conducted among foresters and users in the Landes de Gascogne and île-de-France areas so as to assess practises and social representations associated with dead wood. From the results of the survey, it appears that there is a diversity of practices and divergences about the implications connected with dead wood. The 64 respondents can be divided into roughly six groups (G1: "industrial foresters", G2: the "silvicultural foresters", G3: the "remote foresters", G4: the "environmentalist foresters", G5: the "naturalists" and G6: the "users"). Among other things, they can be differentiated by their management practises, their degree of knowledge about and concern with ecology, their social networks, their aesthetic judgment, their perception of risks and their economic requirements. While underscoring the scarce popularity on average of the biodiversity-related issues, this sociological survey also highlights: the need for a minimal regulatory framework to achieve integrated retention of dead wood, the serious concern of forest managers in the Landes with plant health risks associated with dead wood, and the need for a functional justification for keeping dead wood in the ecosystem.
... In addition, the conservation status of the forest fragments (WDInat) was also negatively correlated with the presence of colonies, suggesting that the establishment of conservation areas adjacent to intensively managed plantations can be a useful preventive method for pest management in forest monocultures (Jactel et al., 2002). This result corroborates with previous studies which found that cutting ants prefer native vegetation in the first stage of succession because there is predominance of pioneer species in contrast to the presence of shadetolerant species, which are present more frequently in conserved native vegetation (Farji-Brener, 2001). ...
Article
Leaf-cutting ants (Atta spp.) are the main Eucalyptus plantation pests that cause successive defoliation, and productivity losses might be significant. Thus, our objective was to evaluate the influence of vegetation composition and landscape structure on the occurrence of leaf-cutting ants in Eucalyptus spp. plantations neighboring areas of Atlantic Forest vegetation. We collected data on the occurrence of ants (Atta spp.) and the amount of loose soil in each ant colony. We calculated the landscape metrics for the area that we divided in landscape planning unit. We proceeded with information-theoretic approach to identify the best set of models with AICc criteria. We found that 81.1% of the ant colonies had an area of loose soil smaller than 1 m², and the diversity of Eucalyptus ages, edges of Eucalyptus plantation, and conservation of native fragments have influence on ant occurrence and reduce their effects. So, an increase in vegetation conservation status, decrease of roads that lead to edges in Eucalyptus plantations, and adoption of age mosaics in production areas disrupts ant occurrence. In addition, better functional and structural conditions favor ecosystem services, such as soil and water conservation, through a reduction in the use of formicidal baits.
... Isolated patches and patch areas at landscape scale in the natural forest system have positive effect for preventing certain insect herbivores from spreading and outbreak (Floater and Zalucki 2000;Jactel et al. 2002;Perkins and Matlack 2002;Ylioja et al. 2005). Establishing small polyclonal cultures of 10-20 ha islands of SRF in a matrix of other land uses is a safer alternative that will minimize the spread and impact of pests (Dickmann et al. 2001). ...
Article
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... Los insectos herbívoros (principalmente larvas de Lepidoptera) pueden considerarse como uno de los grupos de mayor representatividad e impacto en las comunidades ya que constituyen ca 90% de los defoliadores de bosques; dentro de este Orden, la familia Tortricidae se ubica entre las cuatro primeras en abundancia y diversidad (Marquis & Whelan 1994, Wold & Marquis 1997. Se estima que la intensidad y la ocurrencia del daño dependen de varios factores inherentes del hospedante, tales como el diámetro del tallo (Jactel et al. 1996(Jactel et al. y 2002, la edad (Maleque et al. 2010), la condición del vigor/estrés (Wenninger & Inouye 2008) y la presencia de compuestos volátiles químicos atrayentes o defensivos (Hanks 1999, Jactel et al. 2002. Estos compuestos, son producidos principalmente en las flores, pero también se encuentran en los frutos, tallos, hojas y raíces (Steeghs et al. 2004). ...
Article
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The present study aims to determine the damage intensity of the pinyon pitch nodule moth, Retinia arizonensis and their possible relationship to some structural parameters: stem diameter, height and coverage, as well as the natural regeneration of Pinus cembroides and P. nelsonii. For their evaluation, sites with 2,500 m² of each species were located. A total of 136 individuals of P. cembroides were recorded, with an average damage of 10.5% (±8.1 SD) in the terminal buds. In P. nelsonii, a total of 47 individuals were found, 46 exhibited damage from R. arizonensis, averaging 4.8% (±4.5 SD), twice less than P. cembroides. We used the Kruskal-Wallis (H-Chi²) to assess the damage of R. arizonensis between species, marked significant difference (p
... However, plantations are commonly even-aged monocultures of relatively narrow genetic stock, and are often planted in locations selected for economic rather than ecological factors, both of which can increase susceptibility to damage by insects and pathogens. In contrast, natural forests are more heterogeneous and tend to harbor more numerous and diverse predator communities, which confronts herbivores with difficult challenges in locating and colonizing suitable host trees (Jactel et al., 2002;Jakel and Roth, 2004). ...
... The same was true for light-trapped moths (Table 4) and malaise-collected beetles (Table 6), although the differences were smaller. Increasing density of herbivores in monoculture is a familiar phenomenon (for a plantation forestry example, see Jactel et al. 2002), which may be due to an increase in favourable resources or a decrease in population control by natural enemies (Root 1973). The resource concentration hypothesis (Kareiva 1983), predicts greater populations of herbivores in monocultures (such as the plantation) where there is great availability of one appropriate host (i.e. ...
Article
Abstract We examined the potential of forest plantations to support communities of forest-using insects when planted into an area with greatly reduced native forest cover. We surveyed the insect fauna of Eucalyptus globulus (Myrtaceae) plantations and native Eucalyptus marginata dominated remnant woodland in south-western Australia, comparing edge to interior habitats, and plantations surrounded by a pastoral matrix to plantations adjacent to native remnants. We also surveyed insects in open pasture. Analyses focused on three major insect orders: Coleoptera, Lepidoptera and Hymenoptera. Plantations were found to support many forest-using insect species, but the fauna had an overall composition that was distinct from the remnant forest. The pasture fauna had more in common with plantations than forest remnants. Insect communities of plantations were different from native forest both because fewer insect species were present, and because they had a few more abundant insect species. Some of the dominant species in plantations were known forestry pests. One pest species (Gonipterus scutellatus) was also very abundant in remnant forest, although it was only recently first recorded in Western Australia. It may be that plantation forestry provided an ecological bridge that facilitated invasion of the native forest by this nonendemic pest species. Plantation communities had more leaf-feeding moths and beetles than remnant forests. Plantations also had fewer ants, bees, evanioid wasps and predatory canopy beetles than remnants, but predatory beetles were more common in the understory of plantations than remnants. Use of broad spectrum insecticides in plantations might limit the ability of these natural enemies to regulate herbivore populations. There were only weak indications of differences in composition of the fauna at habitat edges and no consistent differences between the fauna of plantations adjacent to remnant vegetation and those surrounded by agriculture, suggesting that there is little scope for managing biodiversity outcomes by choosing different edge to interior ratios or by locating plantations near or far from remnants.
... Although not measured in this study, we observed that wood wasp capture may have been inßuenced by adjacent stands (Ϸ0.5Ð3 km) and pine slash left on the forest ßoor after precommercial thinning. Composition of adjacent forest stands has been correlated with severity of attack and abundance of pest species in other studies (i.e., Kouki et al. 1997, Jactel et al. 2002. Jactel and Brockerhoff 2007 determined that monoculture stands were affected by higher herbivory rates than the same species from diverse stands in a meta-analysis of 119 studies (see also Castagneyrol et al. 2013). ...
Conference Paper
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A field experiment was conducted to better understand what type of forest stand structure (un-managed pine plantation, managed pine plantation, mixed pine-hardwood forest, old growth forest) a native woodwasp (Sirex nigricornis) prefers in Mississippi. Lindgren funnels baited with mesh bags containing pine slash (changed every two weeks) were used to trap the woodwaps during the Fall of 2011. Fixed-plot forest measurements were also recorded in each stand. Analyses was conducted using the GLIMMIX procedure in SAS 9.2. Mean weekly woodwasp captures were significantly greater (p=0.0143,F3,569=3.93) in un-managed pine plantations (21.42 ­+ 7.74) than in managed pine plantations (11.42mixed pine-hardwood forests (10.58, and old growth forests (7.33. Sirex noctilio, a recently introduced pest to the northeastern United States, could pose a great threat to Southeastern pine forests. Further research might allow measurements of the abundance of S. nigricornis to serve as an indicator for land managers to determine if their stands are at high risk of S. noctilio attack.
... Mixed forests on the other hand have greater semiochemical diversity than pure host stands as non-host angiosperms would disturb olfaction-guided host selection and hence reduce the likelihood of outbreaks of coniferinfesting bark beetles (Huber and Borden, 2001;Zhang et al., 2001). Schowalter and Turchin (1993) showed that a mixed stand of deciduous species may decrease the spread of D. frontalis while homogenous stands experience outbreaks of forest insect pests more often than heterogeneous stands (Jactel et al., 2002). Research is required to explore whether such effects could be practicable in pine forests. ...
... Pathways that are not described in this study may, among other things, be linked to the dominance of Pteridium aquilinum (bracken) (Den Ouden 2000), grazing and browsing (Engelmark et al. 1998;Blatt et al. 2001), exotic species (Maddelein et al. 1990), changing resources (Emmer 1995) and/or pests (Jactel et al. 2002). These factors can substantially change the trajectories of stand development, especially in those pathways where Quercus and Fagus potentially play an important role. ...
Article
Question: What are the main pathways of long-term stand development in forest ecosystems on oligotrophic and acidic sandy soils? Location: Nine forest reserves at different locations in The Netherlands; all ageing Pinus sylvestris forests that are no longer managed and where massive regeneration of broad-leaved species is often reported. Methods: Agglomerative cluster analysis was used to define structural classes from forest reserve data. Sequences of structural classes, representing different trajectories of stand development, were constructed with the aid of a process based gap model. Results: Four main pathways of stand development could be distinguished. Three pathways are linked to gap dynamics, and lead towards dominance of Betula, Quercus or Fagus. They differ in light availability for regeneration and/or seed tree availability. The fourth pathway comprises of development patterns after major disturbances. Conclusions: The new methodological approach, combining the empirical strength of forest reserve data with the predictive ability of a process based model, made it possible to detail and quantify insights into structure and dynamics of forests on poor sandy soils. Some factors not included in the study can substantially influence pathways, especially those where Quercus and Fagus potentially play an important role.
... In addition to stand size, forest diversity at the landscape level is likely to be an important modifier of the effects of stand diversity on pests and pathogens. Several recent studies have shown that the more isolated stands of host trees are within a forest mosaic of non-host species, the less susceptible they are to insect pests (Cappuccino et al. 1998;Floater and Zalucki 2000;Jactel et al. 2002). This indicates that the effectiveness of stand diversification as a means of pest and pathogen control may depend on the diversity of surrounding stands, meaning that the effects of forest diversity have to be considered simultaneously at both the stand and the landscape level. ...
Article
Pure forest stands are widely believed to be more prone to pest outbreaks and disease epidemics than mixed stands, leading to recommendations of using stand diversification as a means of controlling forest pests and pathogens. We review the existing evidence concerning the effects of stand tree-species diversity on pests and pathogens in forests of the boreal zone. Experimental data from published studies provide no overall support for the hypothesis that diversification of tree stands can prevent pest outbreaks and disease epidemics. Although beneficial effects of tree-species diversity on stand vulnerability are observed in some cases, in terms of reductions in damage, these effects are not consistent over time and space and seem to depend more on tree-species composition than on tree-species diversity per se. In addition, while mixed stands may reduce the densities of some specialized herbivores, they may be more attractive to generalist herbivores. Given that generalist mammalian herbivores cause considerable tree mortality during the early stages of stand establishment in boreal forests, the net effect of stand diversification on stand damage is unlikely to be positive.
... On the other hand, the REL treatment and the NV conditions drastically increased the incidence of attack by white pine weevil ( Figure 2) compared with that in the control conditions, in which planted seedlings were growing within a high density of broadleaf competitors (ϳ4,000 stems/ha). This response supports the fact that insect herbivory is reduced in tree mixtures (a condition found in our control plots) compared with that in single-species stands (a condition found in REL and NV plots), especially when the mixed forests are composed of taxonomically distant tree species (Jactel et al. 2002, Jactel andBrockerhoff 2007). Nonhost volatiles, alteration of soil composition, and overstory shade are proposed as potential factors to explain the relative protection offered by competing vegetation against white pine weevil attacks on conifers (Koopmans et al. 2009). ...
Article
In Canada, Norway spruce (Picea abies [L.] Karst.) is an exotic species mainly used as a fast-growing tree in intensive silviculture. However, this species is sensitive to attacks by white pine weevil (Pissodes strobi Peck [Coleoptera: Curculionidae]) (WPW), a pest that girdles and kills leader shoots, targeting open-growing individuals with fully sunlit terminals. We hypothesized that there is a compromise when releasing planted Norway spruce between growth interference by competing vegetation and avoiding creation of favorable conditions for attacks and growth reduction by WPW. We evaluated the effects of stock type, scarification, and vegetation management on WPW incidence and early Norway spruce growth in southeastern Québec (Canada). Our study confirmed that after 11 growing seasons, the growth of Norway spruce seedlings was driven by the presence of competing species, a factor that can be managed through vegetation control. Although released seedlings were at a higher risk of WPW attack, the trees were ultimately taller than those growing in control conditions. Although significant in some treatment combinations, stock type effects were limited and marginal compared with vegetation effects. Scarification did not improve seedling establishment on this site characterized by a thin humus layer.
... Nevertheless, little is known about the breeding ecology of woodland birds in conifer plantations compared with natural woodlands (Gibb & Betts 1963;van Balen 1973;Jactel et al. 2002). In general, the primary food resource of tits, the most common insectivorous woodland birds in Japanese forests, is caterpillars, mostly Lepidoptera and Hymenoptera (e.g. ...
Article
Conifer plantations generally provide less food for woodland birds such as tit species than do broadleaf or mixed forests. We examined whether small patches of broadleaf (thus, caterpillar-rich) trees in a Japanese cedar (Cryptomeria japonica) plantation could improve the breeding success of coal tits (Periparus ater) and varied tits (Poecile varius) using nest boxes in the plantation. We evaluated the relationships between the distribution of the broadleaf trees (the minimum distance from each nest box to the nearest patch and the total area of broadleaf patches within 25, 50, 100, and 200 m from each nest box) and breeding performance (clutch size, number, and body mass of fledglings, fledging success, fledge rate, and nestling period). Coal tits selected nest boxes regardless of the distribution of broadleaf patches. By contrast, varied tits nested preferentially within 50 m of broadleaf patches and, within 50 m, favored boxes near a larger total area of broadleaf patches than coal tits. The breeding performance of both species was not affected by the distribution of patches; however, the clutch size of varied tits (but not coal tits) tended to decline in nests ≥50 m from broadleaf patches, and there were no large clutches in such positions. The broadleaf trees might have improved the habitat quality, particularly for varied tits, by providing food resources. Thus, broadleaf patches as foraging sites and nest boxes as breeding sites could both be critical to the breeding success of woodland birds in conifer plantations.
... Composition of adjacent forest stands has been correlated with severity of attack and abundance of pest species in other studies (i.e. Kouki et al. 1997, Jactel et al. 2002. In this study, we observed that funnel traps in mixed and old growth stands that were closer to adjacent stands, consisting of pine monocultures, had increased captures of S. nigricornis. ...
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The Eurasian wood wasp, Sirex noctilio, is considered a secondary pest in its native range; however, it has caused significant economic damage when introduced to pine plantations in the Southern Hemisphere. Sirex noctilio was recently introduced to the northeastern U.S., which has raised concerns about its potential impact on Southeastern pine plantations. This research was conducted to understand how silvicultural management affects populations of a native wood wasp, Sirex nigricornis, a wood wasp with similar ecosystem functions as S. noctilio. Sirex nigricornis abundance was higher in un-managed pine plantations than in managed plantations, mixed, and old growth forests. Additionally, geospatial models were built displaying S. noctilio hazard for the Southeastern U.S. based on oviposition host preference assays and historical outbreak information. Sirex noctilio hazard models will inform land managers about areas of greatest concern under various scenarios and should be used to decrease susceptibility of pine forests to this pest.
... For example, a study on spruce budworm, Choristoneura fumiferana, reported lower balsam fir mortality in stands surrounded by nonhost deciduous forest than in stands within large coniferdominated forest (Cappucino et al. 1998). Similarly, Jactel et al. (2002) showed that pure stands of maritime pine bordered by a mixed woodland of broad-leaved species suffered fewer attacks by the stem borer Dioryctria sylvestrella than pure stands situated within a monoculture of pine trees. These findings indicate that the preservation or restoration of mixed-species woodlands, e.g., in gaps where site conditions or stand accessibility make timber production less profit-able, could provide the basis for a more sustainable management of plantation forests. ...
... 10,11 Surveys revealed that as a result of KPCP infestation, some woodlands do not even harvest KP seeds in the Changbai Mountain Reserve, Jilin Province, one of the main planting areas of KP. 12,13 KPCPs have seriously affected the growth of local forests and economic development. 14 Compared to biological control 15 and silvicultural control, 16 which are green and nonpolluting but have a long control cycle, chemical control, which is fast and efficient, is more suitable for pine pest control. 17 Aerial spraying by aircraft has been a popular method of chemical control in recent years, with the advantages of flexibility, low cost and high operational efficiency, and is particularly appropriate for large-scale forestry operations in mountainous areas. ...
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Background: Aerial application, a spraying method with aircraft as the application platform, is one of the most important contents of pest control in pine forests. This work aimed to investigate the movement and distribution patterns of droplets and the pest control effectiveness of helicopter spraying on Masson pine (MP) and Korean pine (KP) trees. In particular, three nozzle types (CP02, CP03 and CP04) were evaluated and compared at the same spray volume rate (15 L·ha-1 ) in both wind tunnel and field trials. Results: The CP04 nozzle with a larger orifice size showed significantly better deposition and penetration, but the precision of flight operation parameters must be strictly controlled when using this type of nozzle. The majority (at least 48%) of the droplets produced by the three nozzle types were concentrated in the range of less than 200 μm, and the spray performance of each nozzle type was more stable in the range of 201-300 μm. The final pest correction control rate (CR) of MP was in the range of 59.24%-95.74% and that of KP was 45.41%-54.39% by helicopter spraying. Conclusion: This study confirmed that it is necessary to select the appropriate nozzle type and ensure accurate flight parameters for aerial application in mountain pine forests. Meanwhile, it also confirms the importance of the timing of operation due to incorrect implementation resulting in poor control effectiveness. This article is protected by copyright. All rights reserved.
... For example, forests increase plantation productivity by increasing pollinator abundance (Taki et al., 2011). The increased vegetation diversity of forests also reduce insect pests in the agricultural landscape (Jactel et al., 2002). Moreover, forest habitats support bat activity in the landscape, which in turn might control insect pests (Riccucci and Lanza, 2014) and economically benefit humans in agricultural landscapes (Boyles et al., 2011). ...
Article
Biodiversity conservation outside protected areas reduces the impacts of anthropogenic activity and improves the benefits of ecosystem services. However, conservation also requires identification and preservation of habitats used by organisms in human-modified landscapes. Since such landscapes are heterogeneous, with fragmented habitats, space use decisions of species are expected to be non-random and dependent on resource distribution. We examined habitat selection by an insectivorous bat, Megaderma spasma in a human-modified landscape, and tested whether insect resources in the habitat drive its selection. Using high-resolution satellite imagery, we classified a 36 km2 area of a biodiversity hotspot in Western Ghats, India, into three major habitat categories: forest, plantation, and open habitat. We then tracked 18 bats across an average of 7.33 ± 3 days using radio telemetry and sampled insect resources in forests and plantations. Compositional analysis suggested that Megaderma spasma showed selection for forest habitats. Mixed-effects conditional logistic regression showed that the odds of bats using forest habitats was on average 5.87 times higher than open habitats. Apportionment analysis of insects trapped in forests and plantations showed that habitat type contributed only 0.4% of the difference in diversity at the insect order level, suggesting that insect resources did not differ between the two habitats. However, the relative abundance of one of the bat's prey (katydids of the genus Mecopoda) was significantly higher in forest habitats than in plantations, suggesting that prey abundance in forests may drive the bat's habitat selection. Remnant forest habitats are important resources for insectivorous bats and need to be preserved for maintaining ecosystem functions in human-modified landscapes.
... For example, forests increase plantation productivity by increasing pollinator abundance (Taki et al., 2011). The increased vegetation diversity of forests also reduce insect pests in the agricultural landscape (Jactel et al., 2002). Moreover, forest habitats support bat activity in the landscape, which in turn might control insect pests (Riccucci and Lanza, 2014) and economically benefit humans in agricultural landscapes (Boyles et al., 2011). ...
Article
Biodiversity conservation outside protected areas reduces the impacts of anthropogenic activity and improves the benefits of ecosystem services. However, conservation also requires identification and preservation of habitats used by organisms in human-modified landscapes. Since such landscapes are heterogeneous, with fragmented habitats, space use decisions of species are expected to be non-random and dependent on resource distribution. We examined habitat selection by an insectivorous bat, Megaderma spasma in a human-modified landscape, and tested whether insect resources in the habitat drive its selection. Using high-resolution satellite imagery, we classified a 36 km² area of a biodiversity hotspot in Western Ghats, India, into three major habitat categories: forest, plantation, and open habitat. We then tracked 18 bats across an average of 7.33 ± 3 days using radio telemetry and sampled insect resources in forests and plantations. Compositional analysis suggested that Megaderma spasma showed selection for forest habitats. Mixed-effects conditional logistic regression showed that the odds of bats using forest habitats was on average 5.87 times higher than open habitats. Apportionment analysis of insects trapped in forests and plantations showed that habitat type contributed only 0.4% of the difference in diversity at the insect order level, suggesting that insect resources did not differ between the two habitats. However, the relative abundance of one of the bat's prey (katydids of the genus Mecopoda) was significantly higher in forest habitats than in plantations, suggesting that prey abundance in forests may drive the bat's habitat selection. Remnant forest habitats are important resources for insectivorous bats and need to be preserved for maintaining ecosystem functions in human-modified landscapes.
... Both the plantations and natural forests have advantages and disadvantages. However, there is a growing concern on the sustainability of planted forests (Powers, 1999), and some of the issues associated with the stands of pure and mixed species have been still undetermined (Jactel et al., 2002). ...
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Large-scale plantations of pine species were done in the bare hills of the Middle Mountain region of Nepal during the early 1980s. There is a growing concern on the sustainability of the planted pine forests in the country due to the presence of invasive alien plant species (IAPS). Invasive alien plant species are considered as one of the drivers of forest degradation and deforestation. Ageratina adenophora is one of the problematic IAPS found in the planted pine forests throughout the country. In this study, we employed different treatments to control the invasion of A. adenophora in the planted pine (Pinus patula) forest. The research design included four different treatments, viz., (i) control, (ii) stem felling, (iii) floor clearance, and (iv) stem felling cum floor clearance in one block (Block I), which was replicated in another block (Block II). The data were collected using circular sample plots with 2m radius. The ANOVA and TukeyHSD Tests were applied during the analysis process so as to determine the effects of treatments on invasion of A. adenophora. The "floor clearance treatment" was found to be significantly effective to reduce the presence of A. adenophora in the planted pine forest. On the contrary, the "opening of forest cover treatment" was found to be conducive to this invasive species to invade the area. The "stem felling cum floor clearance treatment" could be an effective strategy to control invasion of A. adenophora in planted forest, but as it demands a high cost, it is likely to be appropriate for small forest areas where promotion of regeneration is of high priority.
... The abundance of insects generally increases with the density of host plants, and insects have a tendency to migrate to patches of host plants (Underwood, Inouye, & Hambäck, 2014). The evidence is also increasing that with high tree diversity associational resistance can form against pests and reduce their damage Harri, Koricheva, & Kai, 2007;Jactel, Goulard, Menassieu, & Goujon, 2002;Jactel & Brockerhoff, 2007;Jacte et al., 2015). Especially in mixed stands with hosts and nonhosts, the nonhosts can reduce the proportion of hosts available to the pest, and the natural enemies of pests are also typically more abundant, both of which increase the resistance to forest pests (Barbosa et al., 2009;Quayle, Regniere, Cappuccino, & Dupont, 2003). ...
... For example, a study on spruce budworm, Choristoneura fumiferana, reported lower balsam fir mortality in stands surrounded by nonhost deciduous forest than in stands within large coniferdominated forest (Cappucino et al. 1998). Similarly, Jactel et al. (2002) showed that pure stands of maritime pine bordered by a mixed woodland of broad-leaved species suffered fewer attacks by the stem borer Dioryctria sylvestrella than pure stands situated within a monoculture of pine trees. These findings indicate that the preservation or restoration of mixed-species woodlands, e.g., in gaps where site conditions or stand accessibility make timber production less profit-able, could provide the basis for a more sustainable management of plantation forests. ...
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Expansion of planted forests and intensification of their management has raised concerns among forest managers and the public over the implications of these trends for sustainable production and conservation of forest biological diversity. We review the current state of knowledge on the impacts of plantation forestry on genetic and species diversity at different spatial scales and discuss the economic and ecological implications of biodiversity management within plantation stands and landscapes. Managing plantations to produce goods such as timber while also enhancing ecological services such as biodiversity involves tradeoffs, which can be made only with a clear understanding of the ecological context of plantations in the broader landscape and agreement among stakeholders on the desired balance of goods and ecological services from plantations
... Plantations or natural regeneration can act as corridors along streams or hedgerows, connecting plantations with natural or unmanaged forests (Carnus et al. 2006). The diversity of the surrounding landscape has demonstrable effects in both natural (Cappuccino et al. 1998) and planted (Jactel et al. 2002) single-species stands. In summary, managers should maintain or enhance structural and functional complexity at all scales, both within and between plantations, because complexity is an impor tant determinant of biodiversity and resilience (Parrotta et al. 1997). ...
Article
The public view of tree plantations is somewhat ambiguous. While planting a single tree is generally considered good for the environment, planting a million trees raises concerns in some circles. Although plantations are often used to compensate for bad forestry practices, to willingly simplify otherwise complex forest ecosystems, or as a strategy for allowing the current petroleum-based economy to continue on its course, we believe plantations have a legitimate place in the sustainable management of forests. Multi-purpose plantations, designed to meet a wide variety of social, economic, and environmental objectives, can provide key ecosystem services, help preserve the world's remaining primary forests, and sequester an important proportion of the atmospheric carbon released by humans over the past 300 years.
... The girdling of the stem by the larval gallery causes an interruption of the sap flow, resulting in trunk malformation and increased risk of windbreak [(Baronio Defense reactions of wood tissues around larval galleries, impregnated with resin, also greatly reduce wood quality. It has been shown that the percentage of attacked trees by D. sylvestrella was significantly lower in pine stands bordered by broadleaved forests than in pine stands surrounded by other pine stands, suggesting associational resistance at the landscape level (Jactel et al., 2002). However, the effect of intimate mixing of pine and broadleaved trees has not been yet investigated. ...
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Climate change and biodiversity erosion are two major threats to the vitality of the world's forests. However, it is difficult to predict the extent to which tree diversity and environmental conditions interact to modify forest health, and in particular resistance and/or tolerance to insect pests. We used a tree diversity experiment with an irrigation treatment to investigate the effect of mixing and diluting host pines (Pinus pinaster) amongst broadleaved trees on pine stem borer (Dioryctria sylvestrella) infestations under contrasting drought conditions. We further tested whether the attack patterns of this primary pest resulted from direct effects of tree diversity and drought, or was indirectly mediated by their combined effects on pine vigor. The total number of stem borer attacks per plot significantly decreased with tree species richness, i.e., increased with the density of pines, being maximum in pure plots. There were more attacks in irrigated plots. Mixing pines with birches resulted in lower plot infestations but only in irrigated plots. The probability of individual tree being attacked was higher in irrigated plots and decreased with increasing pine density. More vigorous trees, i.e., with higher radial growth, were more likely to be attacked. We suggest that the pine stem borer is attracted by the volatile organic compounds released by the resin exuding from bark cracks. Bark fissuring increases with radial growth, which is enhanced by irrigation and reduced intraspecific competition in low-density pine plots. The presence of birch limits plot infestation, probably because it disrupts host-finding behavior through repellence by non-host volatiles. This phenomenon is mainly observed when pines are vigorous, i.e., when they are irrigated, and particularly attractive to the stem borer. Our results confirm that more severe droughts decrease the attacks by primary pests feeding on tree trunks, by reducing host tree vigor, and that focal tree species can obtain protection against specialized insect pests when mixed with non-host species. The functional characteristics of herbivorous insects are therefore to be taken into account in predicting the interactive effects of climate change and loss of diversity on forest health.
... Higher habitat diversity can support alternative hosts of indigenous parasitoids and provide a variety of microhabitats for improving chances of successful parasitism and egg-laying. A higher parasitism rate has been recorded in other systems with higher habitat diversity (Marino and Landis 1996;Jactel et al. 2002;Kruess 2003) and more specialized parasitoids were found in modified habitats, with reduced attack rates on alternative hosts (Tylianakis et al. 2007). ...
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The chestnut gall wasp (CGW), Dryocosmus kuriphilus, an invasive pest native to China, has caused severe yield and economic losses to chestnut production in Europe since its arrival in 2002. In Southern Italy, the complex of indigenous parasitoids colonizing CGW was monitored between 2013 and 2015, with the aim of estimating the composition of the indigenous parasitoid complex, its ability to control CGW populations, and the interactions of both factors with several measured environmental parameters. We compared results among three differently managed field types. Results showed an increase in the rate of parasitism both when the host population density was lower and in unmanaged chestnut stands with more natural conditions. The percentage of parasitism in galls was related to morphological traits of the galls and to higher seasonal temperatures, which reduced the parasitism intensity because CGW develops earlier under such conditions. The host–parasitoid mortality inside galls varied among sites and was associated mostly with rot fungi during wet spring and summer months. Parasitoid species richness was similar among the study sites, but the proportion of parasitoid species differed between orchards and unmanaged coppice stands. The timing of attack by parasitoids followed a species-specific successional sequence throughout the larva-to-adult life cycle of the CGW. These interactions should be considered in future research on trophic relationships and when modeling invasive scenarios for new pest species.
... However, among both the forester community and the general public, the belief that science can prevent and eliminate risks is still very prevalent, even if some foresters are beginning to depend more and more on nature to restore balance to ecosystems. Theses opinions can be found when interviewees expressed their interest in biodiversity (variable Biodiv) and in broadleaves (variable Intfeuil) as an efficient means of mitigating pest damage in maritime pine forests (Jactel et al. 2002). Foresters also have very different opinions about the benefits of deadwood conservation (variable IntBoisM) and slash harvesting in providing bioenergy (variable Remanent). ...
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Forest owners are confronted with contradictory views on the importance of deadwood. Environmentalists argue that it should be left in the forest to conserve biodiversity, provide a habitat for specific fauna and flora, and maintain soil quality through wood decay. Conversely, industrial stakeholders, and some public decision makers, advocate harvesting deadwood. Based on a sociological survey and qualitative interviews, we first analyzed the detailed environmental opinions and values of four groups of French foresters as well as their attitudes towards biodiversity, in particular regarding deadwood conservation. We identified various types of attitudes towards deadwood, which could be seen as waste, an unprofitable by-product, a meaningless entity, or a key part of the ecosystem. We then studied the arguments leading them to choose between deadwood conservation and deadwood harvesting for bioenergy production. On one hand, foresters are interested in short-term profitability and pest control, while others fear potential loss of fertility. Finally, the article shows that specific approaches to deadwood conservation ought to be negotiated at a local scale, pending further scientific investigation into the impact of deadwood on biodiversity and the development of more positive attitudes toward ecological concerns in the forest owners’ community.
... Enriching the understorey plant community would favour upper consumer trophic levels as well, because bottom-up effects, such as the availability of host species across habitats, can have strong impacts on upper trophic levels. This could promote natural enemies of herbivore pests (Jactel, Brockerhoff, & Duelli, 2005;Jactel, Goulard, Menassieu, & Goujon, 2002;Quayle, Regniere, Cappuccino, & Dupont, 2003), which is one of the potential reasons why there tend to be lower population densities of damaging insects in mixed plantations than in monocultures (Guyot, Castagneyrol, Vialatte, Deconchat, & Jactel, 2016;Jactel & Brockerhoff, 2007). Besides these factors, the public largely prefers diverse stands over monocultures (Hartley, 2002). ...
Article
Converting natural areas into land used for production causes dramatic changes in the configuration of landscapes. Both the loss and fragmentation of native habitats contribute to biodiversity loss worldwide and the consequent creation of artificial edges can have a significant influence on community assembly. The conservation value of plantation forests has been identified for specific species, but it is not clear whether exotic pine plantations can also be used for the preservation of native communities in general. 2.We studied whether community composition of different trophic levels (plants, herbivorous caterpillars, parasitoids) changed across native Nothofagaceae forests to exotic pine plantations, and whether habitat edges affected communities differently depending on the forest type considered. To accomplish this, we sampled plants, herbivorous caterpillars and parasitoids in native Nothofagaceae and exotic pine plantation forests and compared community composition of each trophic level across habitats. 3.We found that community composition of plants, herbivorous caterpillars and parasitoids differed significantly between native and exotic plantation forests, and that variation in the composition of the upper trophic levels was strongly dependent on variation in the composition of the lower trophic level. Moreover, differences in community composition were mostly the result of species turnover, suggesting that plantations are complementary habitats for some species, but cannot be a substitute habitat for all native forest species. Furthermore, edge effects had a strong impact on the composition of native communities, such that certain species were only present in the interior of the native habitat. 4.Synthesis and applications. Large areas of native vegetation, where the interior remains intact, are essential to preserve species that are susceptible to edge effects and that cannot occupy other habitat types. Creating straight instead of winding edges could decrease the impact that plantations have on native forests. Furthermore, increasing the representativeness of native plant communities in exotic plantation forests would cascade up to higher consumer trophic levels, considerably increasing the conservation value of these commercial stands. This article is protected by copyright. All rights reserved.
... Although not measured in this study, we observed that wood wasp capture may have been inßuenced by adjacent stands (Ϸ0.5Ð3 km) and pine slash left on the forest ßoor after precommercial thinning. Composition of adjacent forest stands has been correlated with severity of attack and abundance of pest species in other studies (i.e., Kouki et al. 1997, Jactel et al. 2002. Jactel and Brockerhoff 2007 determined that monoculture stands were affected by higher herbivory rates than the same species from diverse stands in a meta-analysis of 119 studies (see also Castagneyrol et al. 2013). ...
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The United States has a rich fauna of native Siricidae (wood wasps), but they are rarely studied because they have limited economic impact. In 2004, a non-native wood-boring pest, Sirex noctilio F., was found established in North America. Because S. noctilio is an economically important pest in pine plantations throughout the Southern Hemisphere, interest in the ecology of American native wood wasp populations has increased. A study was conducted during fall 2011 to investigate the effects of forest stand type and characteristics on native wood wasp abundance, and to describe their right phenology in northeastern Mississippi. In total, 609 native wood wasps were captured, consisting of 608 Sirex nigricornis F. and one Urocerus cressoni Norton. There were significant treatment and location effects that influenced wood wasp abundance. The right period of wood wasps captured in our study (October-December) was similar to studies in the southeastern United States, but differed from results in Minnesota and the northeastern United States (June-October). Woodwasp abundance was significantly correlated with higher basal area, smaller tree diameter at breast height, and shorter trees, all indicators of forest stand stress. It appears proper silvicultural management of pine plantations may reduce native wood wasp population abundance in the southeastern United States, as it does to S. noctilio in the Southern Hemisphere. We propose implementing management models used for the southern pine beetle to reduce stand hazard of future infestations of native and invasive wood wasps.
Article
The brown planthopper (BPH), Nilaparvata lugens (Stål), which periodically erupted in tropical Asian rice before the 1960s, became a major threat after farmers adopted green revolution technologies in the 1960s. Management and policy changes in the 1980s and 1990s emphasized non-insecticidal tactics to avert BPH outbreaks. However, insecticides have resurfaced as the primary means for controlling rice insect pests and tropical Asian countries have recently experienced planthopper outbreaks in record numbers. Our review of factors that have contributed to the outbreaks points to insecticides as the most tangible outbreak factor primarily because of their harmful effects on natural enemies. BPH resistance to insecticides and especially imidacloprid has increased the probability of outbreaks as farmers have applied increasing quantities of insecticide in an attempt to combat resistant populations. Similarly, heavy use of nitrogen fertilizer, especially on hybrid rice, has increased the potential for outbreaks. Other factors triggering outbreaks are less documented, but we discuss the possibility that the high outbreak synchrony in geographically separated populations of BPH may suggest a “Moran effect” such as climate that promotes an environment favoring above-average increases in BPH populations. Also, we hypothesize that BPH functions as a metapopulation and, as such, periodic outbreaks could be a natural phenomenon requiring resupply of planthoppers into vacant areas to ensure genetic linkage among subpopulations. We conclude with a series of recommendations for research and policy changes aimed at better understanding the cause of BPH outbreaks and for developing sustainable management practices to prevent future outbreaks.
Article
The western pine beetle, Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae, Scolytinae), is a major cause of ponderosa pine, Pinus ponderosa Douglas ex Lawson, mortality in much of western North America. We review several years of research that led to the identification of Verbenone Plus, a novel four-component semiochemcial blend [acetophenone, (E)-2-hexen-1-ol + (Z)-2-hexen-1-ol, and (-)-verbenone] that inhibits the response of D. brevicomis to attractant-baited traps, and examine the efficacy of Verbenone Plus for protecting individual trees and forest stands from D. brevicomis infestations in British Columbia and California. In all experiments, semiochemicals were stapled around the bole of treated trees at approximately equal to 2 m in height. (-)-Verbenone alone had no effect on the density of total attacks and successful attacks by D. brevicomis on attractant-baited P. ponderosa, but significantly increased the percentage of pitchouts (unsuccessful D. brevicomis attacks). Verbenone Plus significantly reduced the density of D. brevicomis total attacks and D. brevicomis successful attacks on individual trees. A significantly higher percentage of pitchouts occurred on Verbenone Plus-treated trees. The application of Verbenone Plus to attractant-baited P. ponderosa significantly reduced levels of tree mortality. In stand protection studies, Verbenone Plus significantly reduced the percentage of trees mass attacked by D. brevicomis in one study, but in a second study no significant treatment effect was observed. Future research should concentrate on determining optimal release rates and spacings of release devices in stand protection studies, and expansion of Verbenone Plus into other systems where verbenone alone has not provided adequate levels of tree protection.
Article
Forest monocultures with tree species outside their native range are assumed to be more prone to insect outbreaks than mixed forests. The present study examined this thesis by observing two lepidopteran pests with different dietary spectra. Lymantria monacha L. (Nun moth) is a pest of the Norway spruce [Picea abies (L.) Karst.] that feeds polyphagously on coniferous and deciduous tree species. The second target species, Calliteara pudibunda L. (Pale tussock moth), is a monophagous pest of European beech (Fagus sylvatica L.). We investigated the relative abundances of these two pests in six forest types: pure spruce, pure beech and four mixed stands with different ratios of both tree species. The moths were caught with light traps.The relative abundances of C. pudibunda appeared to be linked to the tree species composition of the investigated forests. The number of individuals and the values of species dominance of C. pudibunda decreased with rising spruce ratio. Beech forests with a small portion of spruce (25%) showed a remarkably strong decrease in the number of C. pudibunda individuals compared to pure beech forests. No significant effects were observed concerning L. monacha and the beech/spruce ratio of the forests, though there was a trend for the dominance of this pest to decrease with rising beech ratio in the forests.
Thesis
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Anthropogenic global change may affect different compartments of the biosphere, atmosphere, or hydrosphere. In particular, increasing atmospheric concentrations of carbon dioxide, anthropogenic changes to biogeochemical cycles, or land-use changes have been identified as particularly important components of global change. In this thesis, we study the effects of human-caused environmental change on ecosystems. In particular, the effects of climatic and land-use changes are addressed. In addition, we address the loss of biological diversity, and the subsequent effects of biodiversity loss on ecosystem processes, such as biological invasions or trophic interactions. The thesis is structured into four subsections. Section 1 covers biodiversity effects on invasion resistance, herbivore performance, and multitrophic interactions. Section 2 investigates effects of climate change on plant-herbivore and above-belowground interactions. Section 3 is about landscape structure, multitrophic interactions and biological control. Finally, Section 4 covers effects of tree biodiversity on multitrophic interactions. While all results are presented as individual chapters, some unifying experimental approaches were followed; we experimentally manipulated (i) plant species and functional richness and composition (The Jena Experiment); (ii) atmospheric Carbon dioxide concentration, drought, warming and herbivory (Climaite Experiment);(iii)Landscape composition and habitat identity and(iv) tree species richness along a natural gradient in the Hainich National Park. We found that (i) plant biodiversity consistently affected ecosystem processes, (ii) multitrophic interactions were bottom-up controlled by plant species richness, (iii) Herbivores reacted more strongly than carnivores, parasitoids or omnivores to changes in plant biodiversity, (iv) global climate change drivers interactively affect herbivore performance and above-belowground interactions and (v) landscape composition and habitat identity can be important predictors of herbivore performance and biological control. Our findings show that protecting plant species richness (and plant biodiversity in the wider sense) can be a good basis for conservation of other organisms and their interactions. Our climate change studies also show that we need a better understanding of global change effects on above-belowground interactions and terrestrial nutrient cycling in order to improve the predictions of predictive climatic models. Overall, future research should aim at experimentally manipulating organism species richness or abundance at multiple trophic levels, combined with manipulations of multiple drivers of anthropogenic environmental change.
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RESUMO Durante o cultivo de shiitake em toros de madeira estabelece-se uma diversidade de insetos, em decorrência das condições locais, da fase de desenvolvimento da cultura e/ou do sistema de cultivo. Objetivando-se avaliar a diversidade de insetos associada ao cultivo deste cogumelo cultivado em toros de Eucalyptus spp. foram realizadas avaliações durante a fase de colonização, situado na Cidade de Arroio do Padre, RS. Para isto utilizou-se armadilha luminosa modelo INTRAL AL 012 (12 volts) na captura dos espécimes. Neste período foram detectadas 9 ordens, sobressaindo-se a ordem diptera com maior predominância, apresentando freqüência relativa de 80,57% e absoluta de 1.393. Nesta mesma ordem, a família Sciaridae foi representada com maior freqüência absoluta, com 1.085 espécimes. PALAVRAS-CHAVE: Cultivo de shiitake, armadilha luminosa, Diptera, Sciaridae. ABSTRACT INSECTS ASSOCIATED WITH THE SHIITAKE [LENTINULA EDODES (BERK.) PEGLER] CROP IN THE CITY OF ARROIO DO PADRE, RS, BRAZIL. The growing of shiitake on wooden logs attracts a variety of insects depending on the local conditions, the phase of development and the growing system. This study was designed to evaluate the diversity of insects associated to the growing of this mushroom on Eucalyptus spp. logs in the county of Arroio do Padre, RS, by way of evaluations during the colonization phase. A model INTRAL AL 012 (12 volts) luminous trap was used to capture specimens. In this period 9 orders of insects were detected, the order Diptera predominating, presenting a relative frequency of 80.57% and absolute frequency of 1,393. In this order, the family Sciaridae was found in the greatest absolute frequently, there being 1,085 specimens.
Technical Report
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Les plantations représentent un outil sylvicole reconnu pour assurer un approvisionnement en matière ligneuse qui répond aux attentes sociétales sur l’aménagement durable des forêts. Toutefois, elles font aussi partie du scénario sylvicole intensif qui a le plus grand potentiel d’artificialisation de la forêt naturelle. Les objectifs du nouveau régime forestier sous‐jacents à l’aménagement écosystémique peuvent alors paraître, de prime abord, en contradiction avec ceux de la sylviculture intensive de plantations, notamment parce que l’aménagement écosystémique s’applique à l’ensemble du territoire. Considérant cela, un groupe d’experts a été mis sur pied pour réfléchir à la manière dont la sylviculture intensive de plantations peut être pratiquée dans un contexte d’aménagement écosystémique. Utilisant une approche par enjeux et solutions dans le cadre d’un processus diagnostique (figure 1), le groupe d’experts a défini et documenté les enjeux associés aux plantations (figure 2; tableau 2), élaboré des solutions pour répondre à ces enjeux (figure 3) et formulé onze recommandations pour que la sylviculture intensive de plantations puisse s’inscrire dans un aménagement écosystémique. Les enjeux concernent notamment l’ampleur, l’emplacement et l’agencement spatial des plantations dans le paysage, les attributs clés de la forêt naturelle et sa résilience, l’acceptabilité sociale ainsi que la productivité et la rentabilité des plantations. Le groupe d’experts a élaboré des solutions à l’échelle du peuplement telles que la mise en place de plantations plurispécifiques intégrant des espèces de la forêt naturelle, la modulation des traitements de préparation de terrain, de gestion des débris de coupe, d’éducation et de coupe finale pour mitiger les impacts ainsi que la réalisation des bons traitements au bon moment pour obtenir la production attendue. Les solutions à l’échelle du paysage concernent notamment l’intégration des préoccupations des parties prenantes, le maintien de la qualité de l’eau et la construction du réseau routier selon les saines pratiques. Les solutions à l’échelle du paysage abordent également la naturalité des plantations (tableau 1) et celle de la matrice forestière. À cet effet, le groupe d’experts recommande que les bonnes pratiques, établies pour chacune des étapes du scénario de plantation, soient appliquées pour augmenter la naturalité des plantations tout en tenant compte des objectifs de production. Il recommande aussi de limiter dans le paysage la proportion des peuplements jugés altérés et artificiels, selon le gradient de naturalité, et de faire une analyse locale et régionale pour définir une stratégie de localisation et d’agencement spatial des plantations.
Article
Setting an object within the frame of Natural Heritage implies stressing on its being natural while at the same time valuable. This paper will study how this is managed by the forest owners in Gascony, starting with their own traditional concept of forest heritage and next whether they are affected or not by the calling into question of this concept. Finally, we will analyse their reactions towards the "ecologization" of forest management. To understand this move, we will rely on three seminal concepts: ecologization (Kalaora), heritage-making (Heinich, 2009), and the setting of mere bones of contention as overall problems (Trom & Zimmerman).
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As the notion of sustainable forest management has developed, a broad range of criteria and indicators for assessing the status of forests has been established. Many of these criteria and indicators relate to the capacity of forest habitats to accommodate and maintain considerable biodiversity while others relate directly to the presence of species or groups of species. As a result of the work done on the latter, there has been growing interest in the significance of biodiversity for forest sustainability, largely echoing the theoretical developments in ecology. Are there key species, umbrella species that guarantee the sustainability of the overall forest ecosystem ? Is maximum biodiversity the appropriate goal ? What state should be used as a baseline to assess the ecological sustainability of a forest ? How is ecological sustainability defined ? This article presents the major indicators relating to the biodiversity of plant and animal species. We discuss their ecological significance and operativity for management purposes.
Technical Report
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Characterising, assessing and valuing ecosystem services from forests and woodlands may be used to examine if forests are sufficiently resilient to meet both the future demands from society, and projected changes in climate. The effects of climate change on the provision of ecosystem services are expected to vary spatially and temporally. Impacts are likely to be most severe in the south and south-east of the UK because of: extreme seasonal shifts in rainfall, especially more extreme wet winter weather and more extreme warm dry summer weather; increasing biotic threats due partly to the proximity to mainland Europe and volume of trade to/from ports in the south. The main impacts of climate change on ecosystem services from trees, woodlands and forests in the UK will be: • Recent increases in tree growth have occurred in Europe, and this is thought partly to be a result of a warmer climate and higher atmospheric CO2 concentrations compared to 50 years ago (Likelihood: very likely / Confidence: high). • The continued ability of trees, woodlands and forests to provide specific ecosystem services determined by management objectives is very much dependent on where they are located, how they are managed into the future, their species and genetic diversity, and the interaction with changes in site condition caused by climate change (Likelihood: likely / Confidence: high). • Impacts on species will vary due to differences in site types. Tree species which are more centrally situated in the core region of their site niche will be less affected by changes in the climate - species at the edge of their niche will be impacted more severely (Likelihood: very likely / Confidence: high). • Damage to drought sensitive species will occur in the medium term in the south of the UK, leading to reductions in growth (Likelihood: very likely / Confidence: High), reduced timber quality (Likelihood: likely / Confidence: medium), and a reduced rate of carbon sequestration (Likelihood: very likely / Confidence: high). • In the medium term (next 35 years) tree growth/yield in the lowlands is likely to decrease by approximately 40% for oak, and decrease by approximately 20% for spruce and pine. In the uplands, over the same period the growth of oak is predicted to increase by 20% and spruce and pine to decrease by 20% and 10% respectively, (Petr et al., 2014b) on average across Britain (Likelihood: very likely / Confidence: high). However, towards the end of the century more frequent extreme events may cause greater reductions in growth/yield (Likelihood: likely / Confidence: medium). • More frequent and more extreme storm events, leading to flooding and water quality issues (Likelihood: very likely/ Confidence: high). There is unlikely to be sufficient woodland creation to reduce the risk of flooding in large catchments where the proportion of forest and woodland is small (Likelihood: likely / Confidence: medium). In smaller catchments, where the proportion of forest or woodland is high, natural flood management is expected to be more successful in attenuating flood hydrographs of medium/high magnitude, but not very high magnitude (Likelihood: likely / Confidence: medium). • Climate change will lead to more mild winters and warm spring temperatures, advancing the date of flushing of many tree species (Likelihood: very likely / Confidence: High). This will increase the risk of frost damage in broadleaved and some coniferous trees (Likelihood: very likely / Confidence: high), and may reduce natural regeneration success (Likelihood: likely / Confidence: high). • Biodiversity in semi-natural and managed woodlands, and associated ecosystem services, are expected to reduce due to climate change (Likelihood: likely / Confidence: medium). Prioritised adaptation action to form ‘bigger, better, more joined up’ woodland habitat will be required to counteract this trend (Likelihood: very likely / Confidence: high). • Under climate change, deer and squirrel numbers will increase through milder winters (Likelihood: very likely / Confidence: high) leading to reduced natural regeneration success, more bark stripping, and reduced timber quality in sycamore, beech and oak woodlands (Likelihood: likely / Confidence: high). • In a warmer and drier climate, the public attitude to forests and woodlands as places for recreation and relaxation will strengthen (Likelihood: very likely / Confidence: very high). • People will increasingly value green space with trees as being an important part of urban infrastructure which helps maintain lower ambient peak summer temperatures (Likelihood: very likely / Confidence: high), and improves the quality of air in towns and cities (Likelihood: very likely / Confidence: high). • Climate change projections will continue to drive forest and land use policy objectives for woodland expansion (Likelihood: likely / Confidence: high). Native and ancient woodland will be managed with thinning interventions to stimulate a sequence of tree cohorts regenerated from seed which may be better adapted to changing site and climate conditions (Likelihood: likely / Confidence: medium)
Technical Report
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Au lendemain de la tempête Klaus qui détruisit 200 000 ha de forêt dans le Massif des Landes de Gascogne en janvier 2009, le Centre Régional de la Propriété Forestière d'Aquitaine fournit une approche analytique sur la gestion forestière particulière de ce massif. Le souhait des auteurs est que ce travail nourrisse la réflexion de tous ceux qui s'intéressent au devenir de la forêt landaise. Actualisation 2015 à partir du document "Eléments de réflexion pour la reconstitution du massif des Landes de Gascogne" CRPF Aquitaine, juin 2009.
Article
Les plantations occupent une place de plus en plus prépondérante dans l'économie forestière mondiale mais ces monocultures apparaissent comme plus sensibles aux attaques d'insectes ravageurs. Les résultats de méta-analyses de la littérature scientifique montrent une augmentation d'environ 30% des dommages sur les essences forestières gérées en peuplements purs par rapport à une gestion en peuplements mélangés. Deux mécanismes écologiques permettent de comprendre la plus grande résistance des forêts mixtes: 1) la présence d'essences non-hôtes réduit la disponibilité en arbres hôtes pour les insectes ravageurs et perturbe les stimuli visuels et olfactifs qu'ils utilisent pour identifier et coloniser ces arbres; 2) la diversité des essences forestières s'accompagne d'une plus grande abondance de ressources et habitats favorables aux ennemis naturels des insectes ravageurs, permettant une meilleure régulation biologique. Ces processus expliquent que la résistance des forêts mélangées est plus grande vis-à-vis des insectes spécialistes que généralistes et augmente avec la diversité fonctionnelle ou phylogénétique des essences associées dans le mélange. La relation entre diversité et résistance des forêts permet d'envisager la conception de plantations plurispécifiques assurant une production plus durable de biens et de services.
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RESUMO O objetivo deste trabalho foi conhecer a diversidade de artrópodes associada ao cultivo de Pleurotus sajor-caju em palha de arroz pasteurizada em ambiente semicontrolado, localizado no sul do Rio Grande do Sul. A captura dos espécimes foi realizada no período de abril a maio de 2007, durante a fase de frutificação da cultura, compreendendo 45 dias. Foram realizadas nove coletas com intervalos de 5 dias, utilizando armadilhas INTRAL AL 012 (12 volts). Capturou-se um total de 3.129 indivíduos divididos em cinco ordens com predominância de Diptera (2.874), Hymenoptera (152), Ortoptera (69), Colembola (59) e Coleoptera (38). A ordem Diptera foi a que apresentou o maior número de famílias, sendo Mycetophilidae (2.530), Sciaridae (264), Cecidomyiidae (10), Phoridae (46), Muscidae (4), Calliphoridae (1) e Culicidae (19).
Chapter
This chapter discusses the significant role agroforestry systems (AFS) play in realizing ecosystem services other than soil productivity improvement, climate change mitigation, and biodiversity conservation. Such “other” services include the improvement of hydrological characteristics and water quality, socio-cultural and recreational services, and facilitation for the development of biodiversity hotspots and ecotourism. The tree–crop interaction effects of AFS that can influence the hydrological processes include improvement of soil water storage through enhanced infiltration rates and reduced runoff losses and increase in biomass productivity per unit of water used. The positive role of agroforestry practices such as the establishment of riparian buffer strips in ameliorating the non-point source pollution of water bodies especially in commercial agricultural systems has been well demonstrated. Results of meta-analyses linking ecosystem services of agroforestry practices to overall soil health are also becoming available to show that agroforestry, compared with crop monocultures, provides higher levels of soil-related ecosystem services. Cultural ecosystem services include the non-material (non-monetary) benefits that ecosystems provide to humans, such as spiritual enrichment, intellectual development, and societal and community benefits including recreational, cultural, and aesthetic values. The homegardens are well known for the array of cultural ecosystem services they provide in many indigenous societies. Plant health issues, including the whole array of pests, diseases, and weeds, are one of the relatively under-investigated aspects of ecosystem services of AFS. Contrary to “over-tourism” that harms communities by overuse and destruction of resources through overcrowding and commercialization, well-planned ecotourism and ecodevelopment operations centered around agroforestry have excellent potential for economic gains and promoting ecosystem health.
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A new species of the genus Macrocentrus Curtis, 1833 (Hymenoptera: Braconidae: Macrocentrinae) described and illustrated: M. sylvestrellae spec. nov. from France and Italy. It is a gregarious koinobiont endoparasitoid of the pine stem borer Dioryctria sylvestrella (Ratzeburg, 1840) (Lepidoptera; Pyraloidea: Pyralidae: Phycitinae), a noxious pest in Pinus plantations in southern Europe.
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The infestation dynamics of Dioryctria sylvestrella was studied in relation to fertilisation and pruning of the Maritime pine. The percentage of infested trees was recorded by comparing three levels of fertilisation doses and four levels of pruning severity. Fertilised trees exhibited significantly greater tree growth and higher infestation rates than controls. The removal of live branches resulted in an increase in D. sylvestrella infestation, demonstrating a significant positive correlation with the number of pruning wounds. A model of infestation behaviour was hypothesised which involved primary attraction mediated by oleoresin components exuding from the pruning wounds. Gas chromatographic analysis of volatile terpenes of the wood resin of Maritime pines showed that infested trees contained a significantly higher percentage of terpinolene. The rate of infestation of ten full-sib families showed a significant positive correlation with the mean percentage of terpinolene. In a cross-table analysis of the interaction between tree diameter and terpinolene richness, the distribution of infested trees frequencies indicated that both tree pruning, which creates bark wounds, and tree vigour, which increases bark cracking, could simultaneously increase wood resin flow, thus enhancing tree attractiveness. Modifications of forestry practices are proposed to reduce stem borer damage .
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Recent criticism of the theory that increased diversity leads to increased stability has led to widespread skepticism about the value of using ecological theory to suggest strategies of agricultural diversification to better control insect pests. A total of 150 published studies which examine the effect of diversifying an agroecosystem on insect pest abundance are summarized; 198 total herbivore species were examined in these studies: 53% of these species were found to be less abundant in the more diversified system, 18% were more abundant in the diversified system, 9% showed no difference, and 20% showed a variable response. Two major problems with the studies were: (I) proper experiments were not conducted to show that differences in pest abundance between more and less diverse systems resulted in yield differences; (2) the ecological mechanisms accounting for the differences in pest abundance were carefully examined in only a few of the studies. A fundamental understanding of these ecological mechanisms is critical to the development of a predictive theory of how agricultural diversification affects insect pests. Empirical data and several theoretical arguments are presented which suggest that differences in pest abundance between diverse and simple systems can frequently be accounted for by the response of herbivore host-finding behavior to the patterns of resource availability, rather than the activities of natural enemies. The development of ecologically sound agroecosystems may well utilize within-field plant diversity, both in developing and in developed regions.
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1. The patterns of arthropod diversity were investigated in 24 montane wetlands in Switzerland. These differed in altitude, management regime (cattle-grazing vs. mowing), vegetation structure (index combining vegetation height and density) and degree of habitat fragmentation. 2. The general arthropod diversity was determined by net sampling at 10 sampling points per site. The diversity of grasshoppers and butterflies was measured by counting species richness at the site and species density (species richness per unit area) on transects. The species richness of grasshoppers and butterflies was found to be more sensitive to the geographical attributes of the site whereas species density was more affected by the habitat quality. 3. Grasshopper diversity decreased within the observed altitudinal range (800–1400 m) and was higher at grazed sites, whereas butterfly diversity was higher at mown sites. Arthropod diversity but not abundance of arthropods was positively related to the vegetation structure. 4. The species richness of butterflies was negatively influenced by the degree of habitat fragmentation: both the size of habitat as well as the area of wetland habitats within 4 km were related positively to the number of specialist wetland butterflies. 5. Late mowing as well as low-density cattle-grazing are appropriate management actions to maintain arthropod diversity in montane wetlands. In order to establish site-specific management plans, the biology of the present target species as well as the historical context should be considered. 6. We suggest that the best protection for the species examined in this study would be a network of wetland sites managed using a variety of traditional, non-intensive methods. This can only be achieved by coordinated planning of conservation measures among sites.
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A synthetic mixture of nine green leaf volatiles (GLVs) including linalool was tested on antennae of Ips typographus (L.) with coupled gas chromatographic–electroantennographic detection (GC-EAD). Strong responses were found to 1-hexanol, (Z)-3-hexen-1-ol, and (E)-2-hexen-1-ol. Weak responses were recorded to (E)-3-hexen-1-ol, (Z)-2-hexen-1-ol and linalool, while hexanal, (E)-2-hexenal and (E)-3-hexenyl acetate elicited no EAD responses. In a laboratory walking bioassay, the attraction of I. typographus females to a synthetic pheromone source was significantly reduced when a mixture of the three most EAD-active GLV alcohols was added to the source. Further reduction in response was obtained when these three alcohols were combined with verbenone (Vn). In field trapping experiments, a blend of 1-hexanol, (Z)-3-hexen-1-ol, and (E)-2-hexen-1-ol reduced I. typographus trap catches by 85%, while ca. 70% reduction of trap catch was achieved by Vn or a blend of (E)-3-hexen-1-ol, (Z)-2-hexen-1-ol, and linalool. The strongest disruptive effect was found when Vn plus a blend of the three most EAD active GLV alcohols was added to the pheromone trap (95% catch reduction). Adding the blend of the three most EAD active alcohols to pheromone-baited traps significantly reduced the proportion of males captured. These three GLV alcohols were also disruptive in the laboratory and in the field when tested individually. Hexanal, (E)-2-hexenal, and (Z)-3-hexenyl acetate were inactive both in the lab and in the field. Our results suggest that these nonhost green leaf alcohols may explain part of the host selection behavior of conifer-attacking bark beetles and may offer a source of inhibitory signals for alternative management strategy for forest protection.
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Planted forests have more than a millennium of history and represent the world''s best hope for meeting global wood requirements in the twenty-first century. Advances in genetic improvement, nursery practices, stand establishment, and tending, harvesting, and manufacturing have boosted plantation yields to a higher level than at any point in history. Despite this, forest managers face a mounting challenge to demonstrate that plantation productivity is sustainable. Tackling this challenge requires a sound understanding of the principles of forest productivity, how they apply to a developing plantation, and how they are influenced by management. In this paper criticisms of plantation forestry are discussed from the basis of world experience, and examples of productivity decline are described. Obvious declines are rare, and can be attributed to poor soil management. However, ambiguities exist and controversy will continue until sustainable productivity can be demonstrated conclusively. Proposed programs aim to provide the technical base needed for sound soil management and sustainable plantation productivity.
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Capillary GC analysis was used to determine the proportion and quantity of terpenes in wood resin, pentane extracts from needles and liber, and headspace samples of needles and pruning wounds in 24 thirteen-year-old maritime pine. Fifteen different terpenes were identified in the samples. Germacrene D and -pinene were the dominant terpenic compounds in the needles, while -pinene and -pinene were dominant in the liber and wood resin. Headspace samples of both needles and pruning wounds contained essentially monoterpenes. Only trace amounts of sesquiterpenes were found in pruning wound emissions. The presence of an oxygenated compound, linalool, in the pruning wound emissions is discussed, although this compound is not found in Maritime pine essential oil. Twelve of the 24 trees studied were infested by Dioryctria sylvestrella. Maritime pine susceptibility to this insect was related to the terpene composition of the different samples.
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‘Edge permeability’ between habitat patches in a mosaic landscape of mixed intense agriculture and semi-natural areas was investigated with directional trap devices along field borders and in a 300-m long transect through crap fields, pasture, wetland and a dry meadow.Almost all identified arthropod species performaned population exchanges over the field borders. Species abundances clearly depend on habitat quality rather than area or distance to related habitat islands. Most insect species collected in sticky traps over crop fields were never or rarely encountered in the vegetation layer. Surface-dwelling flightless species showed gradual transitions over the field borders. ‘Hard edge’-species tended to be specialists for undisturbed perennial habitats, while ‘soft-edge’-species with a diffuse distribution were mainly associated with annual crops.It is concluded that in cultivated areas a mosaic landscape of small-sized crop fields and semi-natural habitats maximizes arthropod diversity and decreases the probability for overall extinction even of rare species.
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Evaluating biodiversity in agricultural areas requires two steps: (i) adequate measurement and (ii) pertinent interpretation. Since the whole spectrum of biodiversity in the sense of the Rio Convention cannot possibly be measured as such, adequate measurable correlates or surrogates have to be found. One possibility are standardized inventories to assess species diversity in specious groups of arthropods. They can provide reproducible and comparable values for estimates of site-specific biodiversity in the form of averaged rarefaction functions for the relationship between numbers of individuals and numbers of species in different habitats. Examples of ‘rapid biodiversity assessment’ are presented and their possibilities and limitations are discussed.At a higher integrative level, biodiversity evaluation can be based on landscape parameters. According to a proposed conceptual model, the ‘mosaic concept’, regional biodiversity mainly depends on structural parameters such as habitat diversity and landscape heterogeneity, and functionally on metacommunity dynamics.Approaches with a combination of both site-specific biodiversity measures and assessments of habitat diversity and heterogeneity are not yet established, but in the near future may lead to a scientifically based evaluation of the potential for increasing biodiversity by appropriate landscape management. In the light of scenarios for global change, maintaining high levels of overall biodiversity in agroecosystems may become as important for ecological sustainability as keeping up high abundances of presently well-adapted beneficial organisms.
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Geostatistics brings to ecology novel tools for the interpretation of spatial patterns of organisms, of the numerous environmental components with which they in- teract, and of the joint spatial dependence between organisms and their environment. The purpose of this paper is to use data from the ecological literature as well as from original research to provide a comprehensive and easily understood analysis ofgeostatistics' manner of modeling and methods. The traditional geostatistical tool, the variogram, a tool that is beginning to be used in ecology, is shown to provide an incomplete and misleading summary of spatial pattern when local means and variances change. Use of the non-ergodic covariance and correlogram provides a more effective description of lag-to-lag spatial dependence because the changing local means and variances are accounted for. Indicator transforma- tions capture the spatial patterns of nominal ecological variables like gene frequencies and the presence/absence of an organism and of subgroups of a population like large or small individuals. Robust variogram measures are shown to be useful in data sets that contain many data outliers. Appropriate removal of outliers reveals latent spatial dependence and patterns. Cross-variograms, cross-covariances, and cross-correlograms define the joint spa- tial dependence between co-occurring organisms. The results of all of these analyses bring new insights into the spatial relations of organisms in their environment.
Book
The book provides the applied scientist, engineer or statistician with an introduction to geostatistics stressing the multivariate aspects. Geostatistics offers a variety of models, methods and techniques for the analysis, estimation and display of multivariate data distributed in space or time. The book presents a brief review of statistical concepts, a detailed introduction to linear geostatistics, and an account of three basic methods of multivariate analysis. Moreover, it presents an advanced presentation of linear models for multivariate spatial or temporal data, including the recent bilinear model of coregionalization, and an introduction to non stationary geostatistics with a special focus on the external drift method.
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The evidence to support the view that insect pest outbreaks occur more frequently in forest monocultures than in mixed-species stands is inconclusive, partly because of the lack of evidence and partly because factors other than stand-species composition strongly affect insect pest status. Several factors may make monocultures more or less prone to insect attack; these include lack of natural enemies, greater concentration of host plants, absence of alternative hosts and the development of closer coincidence between insect and plant phenologies. -from Author
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Planted forests have more than a millennium of history and represent the world's best hope for meeting global wood requirements in the twenty-first century. Advances in genetic improvement, nursery practices, stand establishment, and tending, harvesting, and manufacturing have boosted plantation yields to a higher level than at any point in history. Despite this, forest managers face a mounting challenge to demonstrate that plantation productivity is sustainable. Tackling this challenge requires a sound understanding of the principles of forest productivity, how they apply to a developing plantation, and how they are influenced by management. In this paper criticisms of plantation forestry are discussed from the basis of world experience, and examples of productivity decline are described. Obvious declines are rare, and can be attributed to poor soil management. However, ambiguities exist and controversy will continue until sustainable productivity can be demonstrated conclusively. Proposed programs aim to provide the technical base needed for sound soil management and sustainable plantation productivity.
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Gas chromatographic analysis of the volatile terpenes of the wood oleoresin of maritime pines showed that the relative proportions of terpenes within the same tree did not vary according to sampling height and date. Pruning and tree vigor did not affect terpene profiles, but oleoresin composition varied widely from tree to tree. The trees attacked byDioryctria sylvestrella contained a significantly higher percentage of limonene, longipinene, and copaene, and a discriminant analysis, using the relative percentage of six terpenes, significantly separated infested and uninfested trees. The olfactory sensitivity of adult moths to a series of 20 volatile chemicals, including maritime pine oleoresin components, was evaluated with the electroantennogram method. Both sexes were sensitive to monoterpenes, oxygenated terpenoid compounds, and oleoresin samples. The use of terpenes as host attractants and biochemical markers for resistance toD. sylvestrella is discussed.
Article
Adoption of within-field monocultures of annual crops in modern farming systems is known to discriminate against and reduce the activity of predatory insects. In Australia, cotton fields are strictly monoculture and lack ecological diversity which could be the major cause of pest problems in the cotton agroecosystem. The utility of crops such as sunflower (Helianthus annuus), safflower (Carthamus tinctorius), sorghum (Sorghum bicolor), lucerne (Medicago sativa) and tomato (Lycopersicon esculentum) as refugia for predatory insects of Helicoverpa spp., when they were planted as strips in cotton fields, was evaluated from 1993 to 1995. Densities of beneficial insects, mainly predatory beetles, bugs and lacewings, were higher in lucerne crops than any other crop tested. In an experiment where lucerne was planted in strips within commercial cotton, the number of predators was highest in the lucerne strip and declined with increasing distance from the lucerne strip to reach their lowestlevel300 m away in the cotton crop. At the end of the study, 7.1, 6.1, 5.8 and 1.5 times more predatory beetles, bugs, lacewings and spiders per metre row respectively were recorded on the lucerne strips than on cotton. When lucerne was interplanted with commercial cotton to compare densities of predators on cotton with and without lucerne strips, 2.1, 2.5 and 1.2 times more predators were recorded on cotton with lucerne strips than cotton without lucerne strips. This indicated that the lucerne strips can serve as a refugium for predators which can then be moved into cotton fields. This study supports the findings of previous researchers that increased habitat diversity in monocultural crops by strip-cropping can increase population density of indigenous predators.
Article
The infestation dynamics of Dioryctria sylvestrella were studied for 2 consecutive years, in both pruned and unpruned maritime pine. In comparing four levels of pruning severity, the percentage of attacked trees and the location of attacks on the trunks were recorded. The level of attack of pruned trees strongly increased with the intensity of pruning, showing a significant positive correlation with the number of pruning wounds. The removal of dead branches did not result in any increase of infestation. The infestation of pruned trees had no contagious effect towards neighbouring unpruned trees. The location of attacks did not differ between either unpruned or any pruned tree treatments. The majority of the attacks were located in the vicinity of the branch insertion, and in 2-to 3-year-old internodes. In the second year, the percentage of pruned re-attacked trees continued to show a significant positive correlation with the severity of pruning. A model of infestation behaviour was hypothesised which involved two distinct phases. First, a primary attraction, mediated by components of oleoresin exuding from the pruning wounds, might allow the selection of an individual host tree. This attraction would be also quantitative and occur for at least 2 years. Second, female moths would select oviposition sites which would improve brood survival, providing easier access to suitable food resources.
Article
Much as Rachel Carson's "Silent Spring" was a call to action against the pesticides that were devastating bird populations, Charles S. Elton's classic "The Ecology of Invasions by Animals and Plants" sounded an early warning about an environmental catastrophe that has become all too familiar today-the invasion of nonnative species. From kudzu to zebra mussels to Asian long-horned beetles, nonnative species are colonizing new habitats around the world at an alarming rate thanks to accidental and intentional human intervention. One of the leading causes of extinctions of native animals and plants, invasive species also wreak severe economic havoc, causing $79 billion worth of damage in the United States alone. Elton explains the devastating effects that invasive species can have on local ecosystems in clear, concise language and with numerous examples. The first book on invasion biology, and still the most cited, Elton's masterpiece provides an accessible, engaging introduction to one of the most important environmental crises of our time. Charles S. Elton was one of the founders of ecology, who also established and led Oxford University's Bureau of Animal Population. His work has influenced generations of ecologists and zoologists, and his publications remain central to the literature in modern biology. "History has caught up with Charles Elton's foresight, and "The Ecology of Invasions" can now be seen as one of the central scientific books of our century."-David Quammen, from the Foreword to "Killer Algae: The True Tale of a Biological Invasion"
Article
Loblolly pine (Pinus taeda L.) seedlings were grown in a greenhouse under conditions of variable water and nutrient availability and then exposed to natural populations of the Nantucket pine tip moth (Rhyacionia frustrana [Comstock]). Seedling growth was directly related to water and nutrient availability. Tip moth oviposition was highest on the most vigorous seedlings, even after accounting for differences in seedling size among treatments. The ratios of mean number of pupae per seedling to mean number of eggs per seedling for each treatment indicated percent tip moth survival may have been lower on vigorous seedlings than on stressed seedlings, but differences may have been due to factors other than the suitability of seedlings as larval food. Larger numbers of heavier pupae developed on vigorous seedlings than on stressed seedlings. Pupal weights were directly related to total nitrogen concentration and inversely related to total phenolic and condensed tannin concentrations of pine shoot tissues. Total phenolic and condensed tannin concentrations were inversely related to seedling growth. These results suggest that tip moth populations will increase rapidly following silvicultural treatments that increase water and nutrients available to young loblolly pines. For. Sci. 36(3):719-733.
Article
The enemies hypothesis holds that predatory insects and parasitoids are more effective at controlling populations of herbivores in diverse systems of vegetation than in simple ones. Eighteen studies that tested the enemies hypothesis are reviewed. Of those studies reporting mortality from predation or parasitism, nine found higher mortality rates in diverse systems; two found a lower mortality rate; and two found no difference. The mechanisms that are thought to underlie the enemies hypothesis and directions for future research are discussed. Evidence suggests that the enemies hypothesis and the resource concentration hypothesis (which predicts that herbivores more easily find, stay in, and reproduce in monocultures of host plants than in polycultures) are complementary mechanisms in reducing numbers of herbivores in diverse agricultural systems.
Article
Biological studies on Dioryctria sylvestrella (Ratz.) (Lep., Pyralidae), a pest of Pinus pinaster Ait in south-west France The moth Dioryctria sylvestrella (Lep., Pyralidae), one of the main pests of the maritime pine (P. pinaster), breeds only once a year in the Massif of the Landes (South-West of France). The 11-month-long larval development takes place in the inner-bark. Pupation, in resin accumulated on the trunk, lasts about 3 weeks. The reproductive flight occurs at night at foliage height (6–9 m above the ground) between June 15th and the end of July, with a peak around July 7th-15th. Neither mating nor the details of oviposition have ever been observed in nature. The females mate and lay several times, 90% of them harbouring 1 to 3 spermatophores. The largish eggs are deposited on the trunks near drops of resin. Each batch contains approximately 10 eggs. A special effort remains to be made to control the breeding of this Pyralidae. La Pyrale des troncs D. sylvestrella Ratz. présente une seule génération annuelle dans le Massif Landais. Le développement larvaire, étalé sur 11 mois, s'effectue dans le liber du Pin maritime. La nymphose dans un amas de résine sur le tronc dure 3 semaines environ. Le vol reproducteur, effectué de nuit au niveau du feuillage (6–9 m) prend place du 15 juin à fin juillet avec un maximum vers le 7–15 juillet. L'accouplement comme les détails de la ponte n'ont jamais été observés dans la nature. Les femelles s'accouplent et pondent plusieurs fois, 90% d'entre elles recélant de 1 à 3 spermatophores. Les oeufs, assez gros, sont disposés sur les troncs à proximité de gouttelettes de résine. Une ponte compte une dizaine d'oeufs. Un effort particulier reste à faire pour maitriser l'élevage de cette Pyrale. Zur Biologie von Dioryctria sylvestrella (Ratz.) (Lep., Pyralidae) an Pinus pinaster Ait in Südwestfrankreich Dioryctria sylvestrella ist einer der wichtigsten Schädlinge an Pinus pinaster. Der Zünsler hat im Massif Landais, Südwestfrankreich, eine einjährige Generation. Die elfmonatige Larvenentwicklung vollzieht sich unter der Rinde, das ca. dreiwöchige Puppenstadium in Harzansammlungen am Stamm. Der Falterflug liegt zwischen dem 15. Juni und Ende Juli, mit einem Höhepunkt vom 7. 7. bis 15. 7. Die Falter schwärmen nachts im Kronenbereich (6–9 m Höhe). Weder die Paarung noch die Eiablage konnte bisher im Freiland beobachtet werden. Die Weibchen kopulieren mehrmals und kommen auch mehrmals zur Eiablage; 80% enthielten 1–3 Spermatophoren. Die verhältnismäßig großen Eier werden am Stamm in der Nähe von Harztropfen abgelegt. Ein Eigelege enthält ca. zehn Eier. Die Errichtung einer Zucht von D. sylvestrella erfordert noch weitere Untersuchungen.
Article
Losses through reduced growth or mortality attributable to pests, diseases, and abiotic disturbances are generally less in intensively managed, planted forests than in natural forests. Among plantation forests, the most healthy forests are those of exotic species growing a long way from their native range (e.g., Pinus radiata D. Don in New Zealand) and the least healthy ones are those of indigenous species (e.g., Eucalyptus nitens (Deane & Maiden) Maiden in Tasmania). The better health of plantations is a reflection of the generally good growing conditions, the proper matching of site to species that is possible in artificial culture and in the case of exotic species, the freedom from the many pests and diseases present in the native habitat of exotics.
Article
The application of diversity/stability considerations in theoretical ecology has led to the emergence of testable hypotheses with implications for biological control and agroecosystem management. The object of applied research in this area has been to achiece predictably stable pest populations (below an economic threshold level) in crop systems. The exacerbation of most insect-pest problems has been associated with increases in crop monocultures at the expense of the natural vegetation, thereby decreasing local habitat diversity. This can seriously affect the abundance and efficiency of natural enemies, which depend on habitat complexity for sources of alternate prey/hosts, pollen and nectar, shelter, nesting and overwintering sites. Plant diversification of agroecosystems can result in increased environmental opportunities for natural enemies and, consequently, improved biological pest control. Agronomically, there are several ways to design plsnt-diverse cropping systems. One way is by manipulating the vegetation of field margins, and managing the species composition and density of plants in ditchbanks, hedgerows, windbreaks and other types of shelter belts. Within-field plant diversity can be manipulated by designing polycultures of various temporal and spatial crop arrangements. The effects of some of these systems on the dynamics of insect populations are discussed, as well as the effects of cover-crop management on pest insects in orchards. Another way to enrich the vegetational structure of cropping systems is through weed management. Weed diversity in the form of weed borders, alternate rows, or by providing weeds in certain periods of the crop growth can have a major impact on insect dynamics.
Article
The interactions of predatory arthropods between natural habitats and arable land were explored. Three questions were asked: (1) Does habitat quality in field margins determine the density of natural enemies overwintering in field margins? (2) Are good sites for natural enemies also habitats which support greater general arthropod diversity? (3) Does the density of predators overwintering in field margins determine their distribution and abundance in adjacent cereal fields in spring? The value of field margins to agriculture was assessed as the density of arthropods overwintering in these habitats. The arthropod groups used for the assessment were known aphid predators which moved out into cereal crops in the spring. This assessment was compared with general arthropod diversity at each site to test whether field margins supporting high densities of predators were also of value to nature conservation in supporting greater arthropod biodiversity. In spring, the spatial dynamics of predatory arthropod species were investigated in cereal crops adjacent to field-margin overwintering sites. The influence of field-margin habitats on natural enemy populations within adjacent crops was evaluated. The enhancement of natural enemies and general arthropod conservation are discussed as components of overall biological diversity at the farm scale.
Article
A methodological approach to the identification of biodiversity indicators in commercial forest stands is illustrated by analysis of the relationships between syrphid (hoverflies) and carabid (ground beetles) community composition and diversity, and stand structure and field layer vegetation. Data were collected from 12 commercial forest sites encompassing a range of climatic conditions and different crop types (Scots pine, Sitka spruce, Norway spruce and Corsican pine) across the UK. Comparisons were also made between unmanaged semi-natural Scots pine woods and Scots pine plantations. For both syrphids and carabids, no differences in species richness and diversity were recorded between semi-natural stands and plantations; one rare syrphid considered to be restricted to semi-natural pine stands was also found in spruce. Syrphid species diversity and richness was higher in southern spruce sites than in the northern sites. Northern sites had distinctive carabid communities, as did sites in the New Forest, a large ancient woodland in southern England. Of the measured habitat variables, vertical stand structure showed the best correlation with species richness and diversity of both carabids and syrphids. Richness and diversity were less in stands with high vertical cover values for canopy layers. Stands with higher field layer cover supported greater syrphid diversity, but lower carabid diversity. Measures of stand structure could be used as potential indicators of syrphid and carabid diversity, but additional habitat parameters also need to be tested.
Article
Increasingly research suggests that the level of internal regulation of function in agroecosystems is largely dependent on the level of plant and animal biodiversity present. In agroecosystems, biodiversity performs a variety of ecological services beyond the production of food, including recycling of nutrients, regulation of microclimate and local hydrological processes, suppression of undesirable organisms and detoxification of noxious chemicals. In this paper the role of biodiversity in securing crop protection and soil fertility is explored in detail. It is argued that because biodiversity mediated renewal processes and ecological services are largely biological, their persistence depends upon the maintenance of biological integrity and diversity in agroecosystems. Various options of agroecosystem management and design that enhance functional biodiversity in crop fields are described.
Article
Collards were grown at Ithaca, New York, in two experimental habitats: pure stands and single rows that were bounded on each side by diverse, meadow vegetation. The arthropods associated with these plants were sampled on 20 dates over a 3-year period. The status of the herbivore species was measured by their rank in biomass in each sample. The two most prominent species, Phyllotreta cruciferae and Pieris rapae, maintained high status throughout the investigation, but another important species, Brevicoryne brassicae, was absent for an entire season. Pit feeders usually formed the most important herbivore guild. Nevertheless, the guild spectrum, which describes the functional structure of the fauna, varied widely in time and space. The size distributions of species and of individuals were both highly skewed toward the smaller sizes. Herbivore loads, the mean biomass of herbivores per 100 g of consumable foliage, were consistently higher in the pure stands. Moreover, herbivore loads varied significantly with season in each experimental habitat. Both the number of herbivore species and the diversity of the herbivore load were greater in the diverse habitat. Biomass was more heavily concentrated among the prominent herbivores in the pure stands; increased dominance, rather than differences in species richness, appeared to be the major cause for the lower herbivore diversity in this habitat. The diversity of predators and parasitoids was higher in the pure stands. Most of the abundant species found on collards shared a similar narrow range of hosts. As a result the species in this core group of herbivores and parasitoids were regularly associated with each other. Predators and the less abundant herbivores tended to be less specialized and served to link the collard association with the surrounding community. Plant-arthropod associations are representative of component communities, well-integrated systems that form portions of larger compound communities. This distinction facilitates the analysis of community structure. Microclimates and the effectiveness of @'enemies@' did not appear to differ sufficiently in the two experimental habitats to account for the observed differences in the herbivore load. The results suggest a new proposition, the resource concentration hypothesis, which states that herbivores are more likely to find and remain on hosts that are growing in dense or nearly pure stands; that the most specialized species frequently attain higher relative densities in simple environments; and that, as a result, biomass tends to become concentrated in a few species, causing a decrease in the diversity of herbivores in pure stands.
Chapter
The third edition of this very successful text book provides an introduction to geostatistics stressing the multivariate aspects for scientists, engineers or statisticians. Geostatistics offers a variety of models, methods and techniques for the analysis, estimation and display of multivariate data distributed in space or time. This book presents a brief review of statistical concepts, a detailed introduction to linear geostatistics, and an account of three methods of multivariate analysis. Moreover, it contains an advanced presentation of linear models for mulitvariate spatial or temporal data, of nonlinear models and methods for selection problems with change of support, as well as an introduction to non-stationary geostatistics with special focus on the external drift method. Applications from very different areas of science as well as exercices with solutions are provided to help convey the general ideas.