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Wilding of a post-industrial site provides a habitat refuge for an endangered woodland songbird, the British Willow Tit Poecile montanus kleinschmidti
Abstract
Capsule
Post-industrial sites that have become wilded by colonizing vegetation can represent important habitat refuges for Willow Tits Poecile montanus, which occupy large territories in early-successional wet woodland and scrub.
Aims
To quantify Willow Tit population density and territory characteristics on a habitat mosaic of wetland, grassland and woodland/scrub, which has developed on a 596 ha area of former coal mining activities in northwest England.
Methods
Field surveys located all 35–37 nests per year during 2017–2019. Territories were estimated using Thiessen polygons around nest sites. Remote sensing data (land cover mapping and lidar) characterized woody vegetation height and coverage across the site and within territories. Changes in coverage between 1990 and 2015 were assessed to estimate the age of woody vegetation. The relationship between territory size and woodland was tested to see if birds secure a similar area and volume of woody vegetation in each territory.
Results
Mean breeding density was 7.3 pairs/km² (excluding 103 ha of ponds/lakes). Estimated territories averaged 13.7 ha, or 6.9 ha in wooded habitat only. The woodland and scrub were a maximum of 25–30 years old and had a mean height of 3.7 m. Larger territories contained a greater coverage and volume of wooded habitat. The site held 1.3% of the national and global population of the British subspecies of Willow Tit.
Conclusion
Willow Tits occur at low density and require large areas of habitat. Wilded post-industrial sites appear to be important for Willow Tit conservation in Britain, but may require ongoing management to maintain the early-successional woodland and scrub associated with new wetlands in former mining areas. Such sites may have a broader conservation value for a range of species.
... Passive rewilding can occur when farmland, industrial or other land becomes abandoned due to economic or social changes [4,5]. Increasingly, however, land may be deliberately taken out of management and abandoned for passive rewilding in order to restore habitats and biodiversity, increase ecosystem services and resilience, and for scientific research [2,[6][7][8]. ...
... Landuse change from farmland to woodland can also result in loss of cultural landscape features, such as hedgerows, and associated traditions [4]. Nevertheless, expanding or restoring woody habitats in intensively farmed landscapes can provide important habitat refuges for some rare bird species [5] and may support a greater regional biodiversity [7,25,26]. However, there is little information for how passive rewilding may influence species communities in the long term. ...
... Rewilding of abandoned land that creates early successional shrubland and wetland mosaics can create refuges for regionally declining birds [5], and Noddle Hill was notable for the abundance of songbirds in this habitat, especially warblers. These included sedge warblers Acrocephalus schoenobaenus, common whitethroats Curruca communis and willow warblers Phylloscopus trochilus, which were scarce in the local farmland and are declining nationally [42,55]. ...
Passive rewilding is a potential tool for expanding woodland cover and restoring biodiversity by abandoning land management and allowing natural vegetation succession to occur. Land can be abandoned to passive rewilding deliberately or due to socio-economic change. Despite abandonment being a major driver of land use change, few have studied the long-term outcomes for vegetation and biodiversity in Western Europe. Studies are also biased towards sites that are close to seed sources and favourable to woodland colonisation. In this case-study, we reconstruct a time series of passive rewilding over 33 years on 25 ha of former farmland that had been subject to soil tipping, far from woodland seed sources. Natural colonisation by shrubs and trees was surveyed at three points during the time series, using field mapping and lidar. Breeding birds were surveyed at three time points, and compared with surveys from nearby farmland. Results showed that natural colonisation of woody vegetation was slow, with open grassland dominating the old fields for two decades, and small wetlands developing spontaneously. After 33 years, thorny shrub thickets covered 53% of the site and former hedgerows became subsumed or degraded, but trees remained scarce. However, the resulting habitat mosaic of shrubland, grassland and wetland supported a locally distinctive bird community. Farmland bird species declined as passive rewilding progressed, but this was countered by relatively more wetland birds and an increase in woodland birds, particularly songbirds, compared to nearby farmland. Alongside biodiversity benefits, shrubland establishment by passive rewilding could potentially provide ecosystem services via abundant blossom resources for pollinators, and recreation and berry-gathering opportunities for people. Although closed-canopy woodland remained a distant prospect even after 33 years, the habitat mosaic arising from passive rewilding could be considered a valuable outcome, which could contribute to nature recovery and provision of ecosystem services.
... Hard et al., 2019;Milbrandt et al., 2014). However, brownfield sites can, under some circumstances, have high ecological value (Beneš et al., 2003;Broughton et al., 2021;Eyre et al., 2003;Gardiner et al., 2013;Macadam and Bairner, 2012;Mathey et al., 2015;Small et al., 2002;Tropek et al., 2010;Woods, 2012). This value arises from features which can include low fertility and/or extreme soil characteristics (Ash et al., 1994) (providing niches for specialist species), earlysuccessional habitats (Broughton et al., 2021), and low levels of disturbance from both humans and predators (Kamp et al., 2015), which may otherwise be rare in the landscape. ...
... However, brownfield sites can, under some circumstances, have high ecological value (Beneš et al., 2003;Broughton et al., 2021;Eyre et al., 2003;Gardiner et al., 2013;Macadam and Bairner, 2012;Mathey et al., 2015;Small et al., 2002;Tropek et al., 2010;Woods, 2012). This value arises from features which can include low fertility and/or extreme soil characteristics (Ash et al., 1994) (providing niches for specialist species), earlysuccessional habitats (Broughton et al., 2021), and low levels of disturbance from both humans and predators (Kamp et al., 2015), which may otherwise be rare in the landscape. As a consequence, there are concerns that repurposing of brownfields may have unintended consequences for biodiversity (Broughton et al., 2021;Fletcher et al., 2011;Meehan et al., 2010), and so the ecological value of such sites should be a consideration during planning. ...
... This value arises from features which can include low fertility and/or extreme soil characteristics (Ash et al., 1994) (providing niches for specialist species), earlysuccessional habitats (Broughton et al., 2021), and low levels of disturbance from both humans and predators (Kamp et al., 2015), which may otherwise be rare in the landscape. As a consequence, there are concerns that repurposing of brownfields may have unintended consequences for biodiversity (Broughton et al., 2021;Fletcher et al., 2011;Meehan et al., 2010), and so the ecological value of such sites should be a consideration during planning. However, there is little direct evidence to suggest how ecological communities associated with brownfield sites compare directly to other land uses, or how brownfield sites contribute to biological richness at landscape scales. ...
Repurposing of brownfield sites is often promoted, because it is perceived that protecting the “green belt” limits damage to biodiversity; yet brownfield sites provide scarce habitats with limited disturbance, so conversely are also perceived to be ecologically valuable. Combining data from three national-scale UK biological monitoring schemes with location data on historical landfill sites, we show that species richness is positively associated with both the presence and increasing area of ex-landfill sites for birds, plants and several insect taxa. Assemblage rarity of birds is also positively associated with presence of ex-landfill sites. Species richness associated with ex-landfill sites declined over time for birds and insects but increased over time for plants. These findings suggest that development of brownfield sites may have unintended negative consequences for biodiversity, and imply that to minimise loss of biodiversity, brownfield site repurposing could be targeted towards smaller sites, or sites in areas with a high density of other brownfield sites.
... The limited information from Europe indicates that such processes have reduced important open habitats in mountainous regions [10], but can benefit some lowland bird, butterfly and plant communities [14,28,29]. Additionally, small patches of restored woodland or early successional shrubland can diversify landscapes dominated by agriculture, supporting a wider variety of species overall [30,31], and providing important habitat refuges for some [32]. Natural expansion of existing woodlands onto adjacent farmland can also buffer mature forest from edge effects and the influence of agriculture [33,34]. ...
... The successional wooded habitats that develop during woodland restoration and passive rewilding can have significant conservation value in restoring biodiversity to degraded landscapes and damaged ecosystems [43,63,76]. In Western Europe, the shrub thicket stage in the initial decades after abandonment is a key habitat for several birds of conservation concern, including the willow warbler Phylloscopus trochilus, willow tit Poecile montanus, turtle dove Streptopelia turtur and common nightingale Luscinia megarhynchos [32,[77][78][79]. Later succession to closed-canopy, oak-dominated woodland favours other declining species, including the marsh tit Poecile palustris and wood warbler Phylloscopus sibilatrix, and largescale afforestation benefits woodland specialists that are sensitive to habitat fragmentation [7,48,49,80]. ...
Natural succession of vegetation on abandoned farmland provides opportunities for passive rewilding to re-establish native woodlands, but in Western Europe the patterns and outcomes of vegetation colonisation are poorly known. We combine time series of field surveys and remote sensing (lidar and photogrammetry) to study woodland development on two farmland fields in England over 24 and 59 years respectively: the New Wilderness (2.1 ha) abandoned in 1996, and the Old Wilderness (3.9 ha) abandoned in 1961, both adjacent to ancient woodland. Woody vegetation colonisation of the New Wilderness was rapid, with 86% vegetation cover averaging 2.9 m tall after 23 years post-abandonment. The Old Wilderness had 100% woody cover averaging 13.1 m tall after 53 years, with an overstorey tree-canopy (≥ 8 m tall) covering 91%. By this stage, the structural characteristics of the Old Wilderness were approaching those of neighbouring ancient woodlands. The woody species composition of both Wildernesses differed from ancient woodland, being dominated by animal-dispersed pedunculate oak Quercus robur and berry-bearing shrubs. Tree colonisation was spatially clustered, with wind-dispersed common ash Fraxinus excelsior mostly occurring near seed sources in adjacent woodland and hedgerows, and clusters of oaks probably resulting from acorn hoarding by birds and rodents. After 24 years the density of live trees in the New Wilderness was 132/ha (57% oak), with 390/ha (52% oak) in the Old Wilderness after 59 years; deadwood accounted for 8% of tree stems in the former and 14% in the latter. Passive rewilding of these ‘Wilderness’ sites shows that closed-canopy woodland readily re-established on abandoned farmland close to existing woodland, it was resilient to the presence of herbivores and variable weather, and approached the height structure of older woods within approximately 50 years. This study provides valuable long-term reference data in temperate Europe, helping to inform predictions of the potential outcomes of widespread abandonment of agricultural land in this region.
... Because of the demands of urban development, the future directions of these two types of unused lands may diverge significantly, although both have crucial conservation functions for urban biodiversity (e.g., increasing green infrastructure in urban landscapes) (Mathey et al., 2015). Thus, unused lands may have unintended positive effects on biodiversity (Broughton et al., 2020;Macgregor et al., 2022) and offer nature experiences for urban residents. Both the ecological value and social contribution of unused lands, including those in the time period at which land use changes, should be fully explored to improve urban biodiversity, increase the network of green spaces (Wolff et al., 2023), and enhance the quality of urban life (Mathey et al., 2018). ...
The worldwide urbanization has resulted in a massive loss of natural habitats, which is threatening biodiversity and socio-ecological sustainability. Urban rewilding is a strategy aiming to restore the complexity, autonomy and self-sustainability of urban ecosystems by interlinking ecological processes while minimizing or gradually reducing human disturbances. The benefits of urban rewilding are widely acknowledged; however, there remains a knowledge gap concerning the identification of suitable locations for urban rewilding and the methodologies for assessing the rewilding potential of urban areas. In this study, we proposed an approach that can be used to accurately identify urban rewilding opportunity spaces (UROS, the existing wildness areas and spaces offering ecological conditions conducive to the establishment of new urban wildness), by integrating data on spatial heterogeneity, biodiversity and human disturbance. UROS in Chongqing, China was evaluated and mapped at the city-wide scale, with a subsequent validation of the UROS results through an assessment of species richness of spontaneous herbaceous communities, which serve as the pioneer species in rewilding processes. The results revealed a positive correlation between high-scoring UROS and increased species richness of spontaneous herbs, thus confirming the feasibility of the UROS assessment method. Eleven primary types of UROS were identified, with the majority displaying scattered or linear distributions. Most very high-scoring UROS are characterized by expansive woodland expanses situated on the outskirts of high-density built-up areas and substantial water bodies within the built-up urban areas. Notably, nearly half of the UROS encompass areas of 900 m 2 or less, underscoring the importance of urban rewilding initiatives targeting not only the preservation of extensive UROS with robust connectivity but also the revitalization of fragmented UROS with limited areas situated within central urban regions. The methodology is applicable to offer insights and spatial guidance in the execution of urban rewilding initiatives and biodiversity conservation efforts, contributing to sustainable regional development in the context of rapid urbanization.
... Due to the scattered and low density of urban residential developments, Vitoria-Gasteiz has a considerable share of vacant and abandoned land, which has been included in the municipal Green Strategy. Yet, previous research warns that the repurposing of such areas may have undesired consequences for biodiversity (Macgregor et al., 2022;Broughton et al., 2020). Therefore, the ecological value of vacant land and brownfields along with its potential for urban wildness for increasing both, local biodiversity and recreational purposes, should be carefully considered (Macgregor et al., 2022;Kabisch & Haase, 2013). ...
Urban green and blue spaces (UGBS) are key for biodiversity conservation. Many studies focus on UGBS benefits for well-being, but how UGBS ecological and quality influence urban biodiversity is still poorly understood. We analysed the predictive accuracy of urban wildness (UW) and habitat quality (HQ) spatial patterns to biodiversity in the city of Vitoria-Gasteiz, Basque Country. Using GIS techniques, we mapped relative UW as a landscape quality, considering remoteness, challenging terrain, and perceived naturalness. We further evaluated HQ using the InVEST habitat quality module, including data on habitat sensitivity to threats (e.g. population density, light and noise pollution, accessibility) and suitability for biodiversity support, based on a parametrization by expert consultation. We compared UW and HQ to observed species richness obtained from crowd-sourced databases as a biodiversity proxy. UW and HQ models predicted general biodiversity urban patterns, being particularly adequate in UGBS. Peripheral UGBS were associated with higher UW and HQ and positively correlated to biodiversity, as opposed to the smaller-sized centrally located UGBS, more exposed to threats. Both predictors significantly explained biodiversity, and HQ better accounted for threat susceptibility in UGBS. Our findings suggest that small-sized UGBS, such as parks and squares, fail to effectively support urban biodiversity, due to their high exposure and vulnerability to threats, particularly in centric areas. Emphasizing efforts in larger centric UGBS with rewilding strategies (e.g. lowering management frequency) and reducing exposure to threats is essential to increase the habitat quality of UGBS and thus support urban biodiversity.
Brownfield sites (e.g., wastelands, disused industrial grounds and power stations) are valuable refuges for urban birds during the breeding season. This owes to the presence of vegetation in different stages of succession, which provide a high diversity of food and breeding resources. However, insufficient research has explored their winter value, when temperatures are lower and food is scarcer. Accordingly, 342 bird and habitat surveys were conducted in brownfield sites, and other land-uses, across Greater Manchester. Bird density estimates were then calculated using Distance software and bird-habitat associations were analysed using Canonical Correspondence Analysis (CCA). Moreover, the impact of brownfield site development on winter bird density from 2000 to 2009 in Greater Manchester was explored using the bird density estimates, and historical image function in Google Earth. In brownfield sites, Pica pica had the highest density estimate (142 per km²), although four species had estimated densities >100 per km² (Turdus merula; Cyanistes caeruleus; Passer domesticus; Aegithalos caudatus). The CCA indicated that Aegithalos caudatus, Cyanistes caeruleus, Parus major, Prunella modularis were associated with Fagus sylvatica, Betula pendula, and Buddleja davidii on brownfield sites, which during the winter 1) produce seeds 2) support overwintering insects, providing a valuable food source. Nevertheless, across land-uses, most species favoured green space and pre-2000 housing. Brownfield sites were most replaced between 2000 and 2009, with 17.8 km², 14.9 km², and 12 km² replaced by commercial, industrial, and post-2000 housing respectively. This is likely to have had a negative impact on the winter density of most bird species, owing to 1) the removal of brownfield site vegetation 2) increases in impervious land cover. Future declines in winter bird abundance could be mitigated by retaining brownfield site vegetation and setting aside brownfield sites in close proximity to green space and pre-2000 housing.
The drivers of animal settlement are core topics in ecology. Studies from primaeval habitats provide valuable but rare insights into natural settlement behaviour, where species are unconstrained by habitat fragmentation and modification. We examined whether territorial male songbirds (wood warblers Phylloscopus sibilatrix) exhibited clustered distributions when settling in extensive primaeval forest. We tested whether settlement patterns were consistent between years, the influence of habitat preference and the spatial extent of these processes. Remote sensing (airborne LiDAR and satellite multi-spectral) and field survey data were combined to investigate settlement at the landscape (tens of km²), plot (46–200 ha) and microhabitat (20 m diameter) scales, by sampling across 5.9 × 4.5 km of the Białowieża National Park (Poland) during 2018–2019. We assessed bird distribution patterns using nearest neighbour analyses, and habitat preference with generalized linear mixed models. Variation in bird density between plots and years was suggestive of large-scale clustering at the landscape scale. At the local plot scale, any clustering was masked by territoriality, with birds appearing dispersed or randomly distributed. At the microhabitat scale within territories, birds preferred a tall, closed canopy forest structure and avoided a dense herb layer of wild garlic patches. Settlement appeared unconstrained by the availability of preferred habitat at the plot scale, which remained unsaturated. Wood warbler settlement apparently involved hierarchical decisions at multiple spatial scales, compatible with potential social attraction, territoriality, habitat preference or predator avoidance. Selecting an appropriate scale of analysis is an important consideration when assessing the clustering of territorial species.
Significance statement
Many songbirds settle in clusters of breeding territories, possibly reflecting patchy habitat quality and/or social attraction. Studies of territory clustering generally come from fragmented, modified habitats, such as secondary forest, which might bias or limit bird distribution. We studied settlement patterns of male wood warblers in an extensive, primaeval forest, where they could exhibit natural behaviour. Spatial analyses of satellite, airborne and field survey data revealed a series of settlement decisions at multiple spatial scales. We found evidence supporting large-scale clustering across the forest, but at the local scale any such clusters were masked by the spacing of birds within territories. A tall forest structure was preferred within the territories, but at larger scales, some birds seemed to compromise habitat quality to settle within a cluster. The results highlight that settlement decisions of animals must be considered at appropriate spatial scales.
N-Mixture models and Distance Sampling are popular and reliable techniques for estimating abundance and density of animals. However, few studies have applied these abundance modelling techniques to bioacoustic data. Only one previous study has employed distance sampling to acoustic data, which found training observers in estimating distances to vocal contacts was critical for estimating reliable densities. In this study I use pre-recorded vocalisations of Willow Tits (Poecile montanus kleinschmidti) - one of the UK’s most threatened bird species with the fastest declining population trend. This species is poorly studied in the UK with no standardised monitoring scheme in place. A new national survey (2019) has been introduced, which advocates using playback methods in February- April, when Willow Tit vocal activity is thought to be at its peak. However, empirical evidence supporting this pattern is scant. Using acoustic data collected in wet woodland habitat in Cheshire, I show that both N-mixture models and distance sampling protocols can reliably estimate abundance and density of Willow Tits in UK wet woodland reserves using acoustic data. Furthermore, training observers through playback trials that use known distances to Willow Tit calls – specifically the furthest known distance to vocalisations - greatly improves distance estimation and in turn reliability of distance sampling density estimates. At the 26 ha Bagmere SSSI local nature reserve study site, N-Mixture models generated a population estimate of only 2.4 individuals whereas distance sampling generated a density estimate of ~7.7 individuals per km2 of wet woodland habitat. These results demonstrate how acoustic recording units can be applied to estimate density and/or abundance of similar declining passerine species, providing implications for future population monitoring studies. Additionally, the peak in Willow Tit vocalisations at Bagmere in 2018 occurred between February and April, providing validity for current methodology proposed in the new 2019 national surveys. The findings of this study offer suggestions for improving use of bioacoustics in surveying Willow Tits and their continued use to calculate reliable population abundance and density estimates.
The British Willow Tit Poecile montanus has undergone a substantial decline in abundance and a severe contraction in range since the 1970s, for reasons that are poorly understood. Breeding failure, due to nest-site competition and predation, has been suggested as a potential factor in the decline, but limited data exist for the nesting ecology and breeding productivity of the species in Britain. We studied a sample of 128 Willow Tit nests in a habitat mosaic of early successional woodland, scrub and wetland in a post-industrial landscape in north-west England, which is increasingly becoming a key refuge for the species in Britain. Results showed that nesting began in April, with standing deadwood of silver birch Betula pendula, common elder Sambucus nigra and black alder Alnus glutinosa being the most frequent nest sites, and the characteristics of nest sites are described. Daily survival rates and overall probability of nest survival are calculated, and details are given for the timing of breeding, clutch size, nestling survival and number of fledglings produced. Overall, 55% of nesting attempts were successful, although many first breeding attempts failed due to Willow Tits being evicted from their nest cavity by Blue Tits Cyanistes caeruleus, or nests being predated by Great Spotted Woodpeckers Dendrocopos major and, potentially, grey squirrels Sciurus carolinensis. Repeat breeding attempts were relatively more successful, but produced fewer fledglings on average. The results are discussed in the context of other studies of Willow Tits and some related species, and also the implications for the conservation of Willow Tits in Britain.
Coal resources play a strategic role in the long-term development of China. Large-scale mining has a considerable impact on the landscape, and it is a long-term heritage of industrialization unique to the Anthropocene. We investigated the macrozoobenthos and water in nine mining subsidence wetlands at different developmental stages (3–20 years) in North China. A total of 68 species were found, and the macrozoobenthos community in the newly formed wetlands showed high diversity. We believe that this high diversity is not random; rather, the high diversity was because of the special origin and development of the wetland. We used three time slices from the timeline of the development of the newly formed wetlands and compared them. It was found that the macrozoobenthos community was significantly affected by the change in the subsidence history. We emphasize that coal mining subsidence should not be merely identified as secondary man-made disasters, as they are often secondary habitats with high conservation value, and their conservation potential lies in the fact that these secondary habitats can replace rapidly decreasing natural wetlands.
Underground coal mining in the North China Plain has created large-scale subsidence wetlands that may attract waterbirds that use them as complementary habitats. However, no study has been conducted to understand avian use of these created wetlands, inhibiting the formulation of effective management plans. Here, we carried out 12 semi-monthly surveys in 55 subsidence wetlands during the 2016–2017 migration and wintering period and performed direct multivariate analyses, combined with variance partitioning, to test the effects of multi-scale habitat variables on the waterbird assemblages. A total of 89 349 waterbirds representing 60 species were recorded, with seasonal fluctuations in species richness and bird abundance. Waterbird community structures were shaped by four groups of variables at local, landscape and human levels with different effects among seasons. Anthropogenic disturbance was the most important factor group, negatively affecting most guilds. Waterbirds in this human-dominated environment are under a variety of potential threats that should be further studied. The subsidence wetlands are still expanding, and if managed effectively, may provide important complementary habitats for a wide array of waterbird species, particularly for those migrating along the East Asian–Australasian Flyway. Our study provides key baseline data regarding the waterbird communities and may help with the designing of effective management and conservation plans.
Analysis of the impacts of social structure on the behaviour and life history of birds is a rapidly developing area of ornithology. Such studies commonly focus on the Paridae (tits and chickadees) as a model group, but detailed assessment of the basic social structure is lacking for many parids, particularly in the non-breeding season. Such baseline information is essential for understanding the organisation of bird populations, including associations between individuals within social and spatial networks. We assessed the non-breeding (autumn–winter) social structure and that during spring (i.e. the breeding season) for Coal Tits Periparus ater in broadleaved forest in southern Britain. Coal Tits were found to be resident and sedentary in this habitat, with birds remaining close to their spring territories during the non-breeding season and associating in small groups averaging 3–4 individuals. Associations were variable, however, with no evidence of stable flock membership, group territoriality or strong pair bonds during autumn–winter. The non-breeding social structure during a year of high population density did not differ from that during a year of low population density, being most similar to a ‘basic flock’ organisation. This contrasted with that predicted for a food-hoarding parid, highlighting the potential differences in social behaviour between different populations of bird species. Such variation in social behaviour can inform our understanding of the evolution of avian social structures and associated behavioural traits, such as food hoarding, and aid the interpretation of intra- and interspecific differences in behaviour.
Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world's largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km(2), a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics.
Climate change and habitat degradation due to land use are the key factors threatening biodiversity. It is important to study both the separate and joined effects of climate warming and land use on biodiversity. In this work long-term population changes of southern boreal forest birds were studied in relation to climate change and direct habitat alteration due to forestry. The study was based on annually repeated bird censuses in 23 consecutive years (1993–2015) in a managed forest landscape. Results were compared with population changes in protected areas where logging is not allowed. During the study period, total bird density declined by 18% with a change in the bird community composition. Out of the 12 most abundant species seven showed a significant negative trend and only one species a positive trend. Population declines could be connected with the direct alteration of habitat as a consequence of forestry or with the effect of climate change in the case of those species which declined also in protected areas. The increased species are abundant across Europe in human-modified habitats. Due to habitat alteration and climate warming, specific characteristics of southern boreal forest bird communities are changing with communities representing a pattern towards global homogenization. Thus, habitat alteration strengthens the negative effects of climate change.
Population estimates of birds have a wide range of practical conservation uses, as well as being of enduring interest to many birdwatchers. Following previous reports by the Avian Population Estimates Panel, in 1997 and 2006, we present the third collation of population estimates of birds in Great Britain and the United Kingdom. There are now thought to be about 84 million breeding pairs of birds in the UK. The ten commonest species contribute 57% of this total, with Wren Troglodytes troglodytes alone providing one in ten of our breeding birds. In all, 23 species exceed one million breeding pairs. The individual population estimates come from a wide variety of sources, many from extrapolation of previous estimates by recognised trend measures, others from new surveys and novel analytical approaches developed since the last report. Despite the exceptional level of detail available for some species, many gaps in our knowledge remain. Recommendations are made to allow a continuing improvement in our understanding of the numbers of birds in GB and the UK. There are many opportunities for volunteer and amateur birdwatchers to make a significant contribution.
There is increasing recognition of the importance for local biodiversity of post-mining sites, many of which lie near communities that have suffered significant social and economic deprivation as the result of mine closures. However, no studies to date have actively used the knowledge of local communities to relate the history and treatment of post-mining sites to their current ecological status. We report a study of two post-mining sites in the Yorkshire coalfield of the UK in which the local community were involved in developing site histories and assessing plant and invertebrate species composition. Site histories developed using participatory GIS revealed that the sites had a mixture of areas of spontaneous succession and technical reclamation, and identified that both planned management interventions and informal activities influenced habitat heterogeneity and ecological diversity. Two groups of informal activity were identified as being of particular importance. Firstly, there has been active protection by the community of flower-rich habitats of conservation value (e.g. calcareous grassland) and distinctive plant species (e.g. orchids) which has also provided important foraging resources for butterfly and bumblebee species. Secondly, disturbance by activities such as use of motorbikes, informal camping, and cutting of trees and shrubs for fuel, as well as planned management interventions such as spreading of brick rubble, has provided habitat for plant species of open waste ground and locally uncommon invertebrate species which require patches of bare ground. This study demonstrates the importance of informal, and often unrecorded, activities by the local community in providing diverse habitats and increased biodiversity within a post-mining site, and shows that active engagement with the local community and use of local knowledge can enhance ecological interpretation of such sites and provide a stronger basis for successful future management.