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1.
We used dung beetles as an indicator group to identify the most important habitats for biodiversity conservation in a Mediterranean traditional agroecosystem. The relationships between traditional grazing and farming activities and biodiversity were analysed by comparing species richness and temporal turnover across three different habitat types, defined according to vegetation structure and human land use. In this study, both spatial (landscape, among-habitats) and temporal (intra-annual, seasonal) analyses were contemplated at mesoscale.The measurement and use of temporal beta diversity (i.e. an index of temporal species turnover) in conservation biology showed that it is a simple method to characterize and compare different habitat species-assemblages, particularly when time seems to be a significant factor in explaining biodiversity features.Our results showed open mosaic areas as the richest and most temporally heterogeneous habitats. We suggest the maintenance of traditional human activities carried out in these areas, since they have been a significant diversification agent, to avoid the loss of the high Mediterranean biological diversity. 相似文献
2.
Urban and agricultural land uses have caused documented declines in diversity of many organisms. However, responses of stream- and riparian-dwelling amphibians and reptiles to anthropogenic land development are collectively understudied and, when studied, are often grouped together as though these two taxa respond in a similar fashion. We surveyed watersheds in four land use categories (reference, pasture, developing, and urban) for amphibian and reptile species richness over a two-year period in the southeastern United States. Total herpetofauna species richness was equivalent among all watershed types, but amphibians and reptiles responded differently to urbanization when analyzed separately. Urban watersheds had significantly fewer amphibian species than all other watershed types, but these losses were counterbalanced by significant increases in reptile species richness in these same watersheds. We also found that local, riparian-scale, habitat differences were strongly correlated with species composition differences between pasture and developing watersheds. While the difference in species composition between pasture and developing sites may have multiple, species-specific explanations, the dramatic differences between amphibian and reptile species richness in urban watersheds suggest broad trends that may be important to conservation planning. Specifically, our observations suggest that urbanization in the studied watersheds alters small streams from closed-canopy, shallow-water features of the forested landscape likely present before settlement by Europeans and favored by many salamanders and frogs to features associated with open vegetation and deeper, warmer waters favored by riverine turtles and snakes. We conclude that amphibians and reptiles, despite some physiological similarities, are not equivalent for monitoring purposes. Additionally, if future development in the Piedmont mirrors current urbanization, then significant faunal shifts seem assured. 相似文献
3.
It has been suggested that an increase in the area of low-intensity land-use on arable land (e.g. set-aside fields and short-rotation coppice), and high or increased farmland habitat heterogeneity, may halt or reverse the observed population decline of farmland birds. We tested these hypotheses by undertaking farmland bird censuses during two contrasting periods of agricultural policies and land-use (i.e. 1994 and 2004) in a farmland region covering a gradient of forest- to farmland-dominated landscapes in Sweden. Local species richness (i.e. at 3 hectare sites) declined significantly between 1994 and 2004. Local species richness was positively related to habitat heterogeneity in both years of study whereas temporal change in species richness was not. Local change in species richness was positively associated with a change in the proportion of non-rotational set aside and short-rotation coppice (i.e. low-intensity land-use forms), but also to changes in the amount of spring-sown crops. However, the effect of low-intensity land-use was significantly dependent on the amount of forest in the surrounding landscape. An increase in low-intensity land-use was linked to an increase (or less marked decrease) in species richness at sites located in open farmland surroundings but to a decrease in richness at sites located in forest surroundings. This interaction between amount of forest and low-intensity land-use could be interpreted as a “rare habitat effect”, where an increase in a farmland habitat only positively affects biodiversity when it was originally uncommon (i.e. open farmland areas). Our results suggest that conservation measures of farmland biodiversity have to be put in a landscape context. 相似文献
4.
In Europe, land use changes follow public policies, and particularly the Common Agricultural Policy. To predict the effect of policies on agricultural practices, landscape, and ultimately biodiversity, requires understanding of the interactions between social, economic and ecological dynamics at regional scale. We studied by means of prospective scenarios the possible effects of agricultural changes on biodiversity in a Mediterranean upland. This area is characterised by extensive grasslands that have been maintained for centuries by agriculture and are now threatened by tree and shrub encroachment. We built four scenarios that describe possible changes in agricultural EU policies by 2030. We selected 15 bird species on the basis of a high natural heritage responsibility of the study area for these species and 45 plant species on the same basis plus local rarity and habitat vulnerability. We analysed how these species were affected by the four scenarios by considering changes in their habitats. For each scenario, we analysed the driving forces that determine land use changes. Landscape dynamics was modelled with a Generalised Linear Model combining environmental and land use factors. Most of the 60 selected species depend on open habitats. Only the scenario where public support was only granted if it provided environmental services had a positive impact on open habitats and their associated biodiversity. This ‘natural heritage’ scenario was also rated positively by local stakeholders. This approach sheds light on the interest of inter/transdisciplinary studies, scenarios, and stakeholder involvement in the definition of public policies for biodiversity conservation. 相似文献
5.
Ruben Limiñana Alvaro Soutullo Beatriz Arroyo Vicente Urios 《Biological conservation》2012,145(1):62-69
Populations of migratory birds can be affected by events happening at both breeding and wintering grounds. The Sahel is a vast region holding a large number of wintering trans-Saharan migratory European birds, and current land-use changes there may represent a threat for these species. We used satellite tracking data from the migratory Montagu’s harrier to evaluate habitat use of the species during the wintering season, and whether the current network of protected areas is effective to provide their habitat needs during that season. We also developed an ecological niche model for the species in Western-Central Sahel to check if the most suitable sites are included within current protected areas. Tracked harriers occupied a large region encompassing a total of eight countries. The most preferred habitats during winter were croplands and some natural vegetation habitats, especially grasslands. Protected areas only covered a small proportion of the overall wintering grounds of tracked harriers and the most suitable areas for the species in Western-Central Sahel. Increasing the extent of preferred natural habitats within protected areas should benefit the conservation of this and probably other insect-eating raptors. However, substantial increases in extent and number of protected areas in sub-Saharan Africa are very unlike to occur. Conservation actions in the region should therefore be mostly focused on improving land use planning and management outside protected areas, specially enhancing agricultural practices to make biodiversity conservation compatible with poverty alleviation. These can be chiefly targeted at an area of <20,000 km2 of very suitable habitat for these species. 相似文献
6.
The main role of conservation planning is to design reserve networks to protect biodiversity in situ. Research within the field of conservation planning has focused on the development of theories and tools to design reserve networks that protect biodiversity in an efficient and representative manner. Whilst much progress has been made in this regard, there has been limited assessment of the sensitivity of conservation planning outcomes to uncertainty associated with the datasets used for conservation planning. Predicted species distribution data are commonly used for conservation planning because the alternatives (e.g. survey data) are incomplete or biased spatially. However, there may be considerable uncertainty associated with the use of predicted species distribution data, particularly given the variety of approaches available to generate a dataset from such predictions for use in conservation planning. These approaches range from using the probabilistic data directly to using a threshold identified a priori or a posteriori to convert the probabilistic data to presence/absence data. We assess the sensitivity of conservation planning outcomes to different uses of predicted species distribution data. The resulting reserve networks differed, and had different expected species representation. The choice of approach will depend on how much risk a conservation planner is willing to tolerate and how much efficiency can be sacrificed. 相似文献
7.
Forest stands are the basic planning units of managed forest landscapes, and the structural composition of these units is important for conservation of biodiversity. We present a methodological approach for identification and mapping of important structural and environmental features of forest stands. Based on an analysis of habitats of red-listed species and a synthesis of results from research on spatial distribution of forest species, we developed a habitat inventory approach (Complementary Hotspot Inventory, CHI) that is currently used in forestry planning in Norway. The CHI maps fine-scale hotspots for 12 habitat types that are further classified according to positions along main environmental gradients (productivity and humidity). Consisting of different substrates in different environments, these habitats to a large degree support different species assemblages. By incorporating both the hotspot and the complementary approach, the CHI produces data tuned for later conservation measures. The high spatial resolution of data facilitates the use of conservation measures at different spatial scales, from single-tree retention to forest reserves. A validation test of habitats identified by CHI showed that the density of red-listed species was four times that of randomly selected old forests. 相似文献
8.
No-take reserves constitute one tool to improve conservation of marine ecosystems, yet criteria for their placement, size, and arrangement remain uncertain. Representation of biodiversity is necessary in reserve planning, but will ultimately fail for conservation unless factors affecting species’ persistence are also incorporated. This study presents an empirical example of the divergent relationships among multiple metrics used to quantify a site’s conservation value, including those that address representation (habitat type, species richness, species diversity), and others that address ecological processes and viability (density and reproductive capacity of a keystone species, in this case, the black chiton, Katharina tunicata). We characterized 10 rocky intertidal sites across two habitats in Barkley Sound, British Columbia, Canada, according to these site metrics. High-richness and high-production sites for K. tunicata were present in both habitat types, but high richness and high-production sites did not overlap. Across sites, species richness ranged from 29 to 46, and adult K. tunicata varied from 6 to 22 individuals m−2. Adult density was negatively correlated with species richness, a pattern that likely occurs due to post-recruitment growth and survival because no correlation was evident with non-reproductive juveniles. Sites with high adult density also contributed disproportionately greater potential reproductive output (PRO), defined by total gonad mass. PRO varied by a factor of five across sites and was also negatively correlated with species richness. Compromise or relative weighting would be necessary to select valuable sites for conservation because of inherent contradictions among some reserve selection criteria. We suspect that this inconsistency among site metrics will occur more generally in other ecosystems and emphasize the importance of population viability of strongly interacting species. 相似文献
9.
Sabine Oertli Dominik Steiner Alexandra Breitenstein Silvia Dorn 《Biological conservation》2005,126(2):195-205
Surrogate taxa as indicators for biodiversity are widely used in conservation biology and ecology. However, available studies on the congruence of species diversity patterns in different taxa yielded inconsistent results, and correlations between taxa were few. To conserve or restore biodiversity in agricultural landscapes, knowledge on the response of different taxa to management regimes is crucial. In the present study we evaluated the congruence of diversity and similarity patterns among three insect taxa, i.e., bees, grasshoppers, and aculeate wasps, in a mosaic landscape in the Swiss Alps comprising extensively used grassland under different management regimes. In addition, we studied the influence of land use on the diversity and species composition of the three taxa. While species numbers were not significantly correlated between any pair of taxa, community similarities were positively correlated between bees and grasshoppers. The number of red-listed species was not correlated with the total number of species in bees and in grasshoppers. None of the investigated taxa reflected the species numbers or community similarities of the other taxa well enough to qualify as a general indicator for biodiversity. Remarkably, land use clearly influenced species composition, while its effect on species numbers was not significant. All management regimes of the grassland in the study area contribute substantially to the overall diversity of the three insect taxa. Conserving the variety of agricultural land uses will be the most promising step towards the conservation of biodiversity in the study area. 相似文献
10.
Biodiversity in Africa, Madagascar and smaller surrounding islands is both globally extraordinary and increasingly threatened. However, to date no analyses have effectively integrated species values (e.g., richness, endemism) ‘non-species’ values (e.g., migrations, intact assemblages), and threats into a single assessment of conservation priorities. We present such an analysis for the 119 ecoregions of Africa, Madagascar and smaller islands. Biodiversity is not evenly distributed across Africa and patterns vary somewhat among taxonomic groups. Analyses of most vertebrates (i.e., birds, mammals, amphibians) tend to identify one set of priority ecoregions, while plants, reptiles, and invertebrates highlight additional areas. ‘Non-species’ biological values are not correlated with species measures and thus indicate another set of ecoregions. Combining species and non-species values is therefore crucial for assembling a comprehensive portfolio of conservation priorities across Africa. Threats to biodiversity are also unevenly distributed across Africa. We calculate a synthetic threat index using remaining habitat, habitat block size, degree of habitat fragmentation, coverage within protected areas, human population density, and the extinction risk of species. This threat index is positively correlated with all three measures of biological value (i.e., richness, endemism, non-species values), indicating that threats tend to be focused on the region’s most important areas for biodiversity. Integrating biological values with threats allows identification of two distinct sets of ecoregion priority. First, highly imperilled ecoregions with many narrow endemic species that require focused actions to prevent the loss of further habitat leading to the extinction of narrowly distributed endemics. Second, less threatened ecoregions that require maintenance of large and well-connected habitats that will support large-scale habitat processes and associated area-demanding species. By bringing these data together we can be much more confident that our set of conservation recommendations serves the needs of biodiversity across Africa, and that the contribution of different agencies to achieving African conservation can be firmly measured against these priorities. 相似文献
11.
Xiongwen Chen Bai-Lian Li Thomas A. Scott John T. Rotenberry 《Biological conservation》2005,124(2):169-175
Analysis of the spatial distribution of all species of conservation importance within a region is necessary to augment reserve selection strategies and habitat management in biodiversity conservation. In this study, we analyzed the spatial aggregation, spatial association, and vegetation types of point occurrence data collected from museum and herbaria records for rare, special concern, threatened, and endangered species of plants, reptiles, mammals, and birds in western Riverside County in southern California, USA. All taxa showed clumped distributions, with aggregation evident below 14 km for plants, 12 km for reptiles, 2 km for mammals, and 10 km for birds. In addition, all combinations of the different species groups showed high positive spatial association. The Santa Rosa Plateau exhibited the highest number of rare, special concern, threatened, and endangered species, and shrubland (coastal sage and chaparral) was the vegetation type inhabited by the most species. Local land use planning, zoning and reserve design should consider the spatial aggregation within and between species to determine the appropriate scale for conservation planning. The higher spatial association between species groups in this study may indicate interdependence between different species groups or shared habitat requirements. It is important to maintain diverse communities due to potential interdependence. The results of the study indicate that concentrating preservation efforts on areas with the highest number of species of concern and the restoration of native shrublands are the most appropriate actions for multiple species habitat conservation in this area. 相似文献
12.
中国的农业生物多样性保护及持续利用 总被引:16,自引:0,他引:16
中国农区内分布有丰富的野生珍稀濒危物种、生境和遗传基因资源,是农业生物多样性保护的重点。中国农业栽培、繁殖及野生生物物种种类繁多,其物种和生境类型都具特有性,由于农业土地的过度开发和不合理利用,以及农业生态环境污染、过量采集等因素,造成我国农业生物多样性品种和分布面积缩小或消失。我国从50 年代开始保护生态系统的工作,特别是在改革开放以来,我国政府在就地保护、迁地保护、保护规划、法制建设、机构建设、宣传培训等方面,采取了一系列的保护措施,农业生物多样性保护和持续利用取得了显著成效。 相似文献
13.
Sergey Venevsky 《Biological conservation》2005,124(2):235-251
National conservation planning should operate with measures of biodiversity similar to those applied globally in order to harmonize national and international conservation strategies. Here we suggest quantitative measures which enable two criteria of the global biodiversity hotspots to be applied on a national level for 74 large countries, and show how these measures can be applied to map national biodiversity hotspots. The plant endemism criteria of global hotspots are captured by quantitative measures of endemism, which are approximately scale-independent and can be corrected to account for a country’s environmental conditions and conservation priorities. The flexible land use criteria for national biodiversity hotspots are defined from percentage of natural vegetation remaining in the global hotspots. The minimum-area-required approach is applied to define the borders of national biodiversity hotspots using data on vascular plants species richness. We show how national biodiversity hotspots can be mapped from the species-energy relationship for vascular plants using climate, topographical and land use data when spatial pattern of species richness is not known. This methodology to map national biodiversity hotspots from abiotic factors is applied to Russia as a case study. Three Russian biodiversity hotspots, North Caucasus, South Siberia and Far East were identified. The resulting hotspot maps cover national-scale environmental gradients across Russia and although they are also identified by Russian experts their actual geographical locations were hitherto unspecified. The large-scale national hotspots, identified for Russia, can be used for further fine scale and more detailed conservation planning. 相似文献
14.
Caroline A. Sullivan David Bourke Micheline Sheehy Skeffington John A. Finn Stuart Green Stephen Kelly Mike J. Gormally 《Biological conservation》2011,(3):1089-1099
A significant policy objective is the need for protection of biodiversity not just within designated Natura 2000 sites, but also in areas that occur outside of these sites. However there is a lack of information on existing semi-natural habitat cover on EU farms, making it difficult to assess whether targets for halting the loss of agricultural biodiversity are being met. To achieve these targets, reliable yet easy-to-use methods are needed for accurately identifying priority areas for conservation actions and monitoring biodiversity on a large spatial scale.Remote sensing, farmland statistics and species data have been used in some EU countries to create maps to estimate the extent of semi-natural habitat cover but these are acknowledged as being too broad scale. In this study, we examined a method of fine-scale prediction of the spatial coverage of semi-natural habitats in lowland farms. A generalized additive model (GAM) was used to investigate the relationships between landscape and farm management variables and the lowland farmland habitat biodiversity on 32 farms outside of conservation designations, in a region of western Ireland. Semi-natural habitat cover on lowland farms could be predicted with a model using stocking density, soil diversity and river and stream length. It is proposed that this model could be used to predict the coverage of semi-natural habitats on farms in other regions of Ireland with similar land-use and landscape. A similar modelling approach could be adapted for application in other regions of Ireland and across Europe with different landscapes to predict semi-natural habitat coverage. 相似文献
15.
Quick biodiversity studies on poorly studied taxa and areas are increasingly popular for setting conservation priorities over a wide range of spatial scales. However, the implementation of such studies is complicated by the variable extent to which the different criteria used in prioritisation are correlated to each other. Using methods of constrained ordination, we examined the species-habitat relationships of carabid beetles based on ground beetle assemblages from 22 sites in the Picos de Europa National Park, northern Spain. We found characteristic species assemblages for subalpine meadows, Genista shrublands, and pastures, whereas mown meadows, heathlands, beech and riparian woodlands were occupied by more habitat generalist species. Species associated with subalpine meadows and Genista shrublands tended to be mostly brachypterous and to have geographic ranges restricted to northern Spain. In contrast, we found no relationship between the degree of species' association with pastures and geographic range-wing size type. Although the species richness was higher in riparian woodlands and mown meadows, we suggest a higher conservation value for subalpine meadows and Genista shrublands across the landscape because they sustain characteristic assemblages dominated by species with restricted ranges and reduced powers of dispersal. Our study suggests that preserving areas in the landscape supporting higher biodiversity will not necessarily preserve those species potentially more susceptible to habitat loss and fragmentation. It also supports the feasibility of biodiversity studies based on multivariate techniques for setting conservation priorities over complex landscapes. 相似文献
16.
Plant species extinction debt in a temperate biodiversity hotspot: Community, species and functional traits approaches 总被引:1,自引:0,他引:1
Julien Piqueray Emmanuelle Bisteau Sara Cristofoli Rodolphe Palm Peter Poschlod Grégory Mahy 《Biological conservation》2011,(5):1619-1629
Destruction and fragmentation of (semi-) natural habitats are considered the main causes of biodiversity loss worldwide. Plant species may exhibit a slow response to fragmentation, resulting in the development of an extinction debt in fragmented plant communities. The detection of extinction debt is of primary importance in habitat conservation strategies. We applied two different approaches proposed in the literature to identify extinction debt in South-East Belgium calcareous grasslands. The first method compared species richness between stable and fragmented habitat patches. The second explored correlations between current species richness and current and past landscape configurations using multiple regression analyses. We subsequently examined results generated by both methods. In addition, we proposed techniques to identify species that are more likely to support extinction debt and associated functional traits. We estimated a respective extinction debt of approximately 28% and 35% of the total and specialist species richness. Similar results were obtained from both methods. We identified 15 threatened specialist species under the current landscape configuration. It is likely the landscape configuration no longer supports the species habitat requirements. We demonstrated that non-clonal species are most threatened, as well as taxa that cannot persist in degraded habitats and form only sparsely distributed populations. We discussed our results in light of other studies in similar habitats, and the overall implications for habitat conservation. 相似文献
17.
Linking habitat suitability and seed dispersal models in order to analyse the effectiveness of hydrological fen restoration strategies 总被引:1,自引:0,他引:1
A.H. van Loon H. Soomers P.P. Schot M.F.P. Bierkens J. Griffioen M.J. Wassen 《Biological conservation》2011,(3):1025-1035
The effectiveness of measures targeted at the restoration of populations of endangered species in anthropogenically dominated regions is often limited by a combination of insufficient restoration of habitat quality and dispersal failure. Therefore, the joint prediction of suitable habitat and seed dispersal in dependency of management actions is required for effective nature management. Here we demonstrate an approach, which links a habitat suitability and a seed dispersal model. The linked model describes potential species distribution as a function of current species distribution, species-specific dispersal traits, the number of successful dispersal events, dispersal infrastructure and habitat configuration. The last two variables were related to water management actions. We demonstrate the applicability of the model in a strategy analysis of hydrological restoration measures for a large fen area in which still numerous endangered plant species grow.With the aid of the linked model, we were able to optimise the spatial planning of restoration measures, taking into account both the constraints of water management practices on abiotic restoration and the effects of habitat fragmentation on dispersal. Moreover, we could demonstrate that stand-alone habitat suitability models, which assume unlimited dispersal, may considerably overestimate restoration prospects. For these reasons, we conclude that linked habitat suitability and dispersal models can provide useful insights into spatially differentiated potentials and constraints of nature restoration measures targeted at the sustainable conservation of endangered plant populations whose habitats have been deteriorated due to undesirable effects of land and water management on abiotic conditions. These insights may contribute to the design of cost-effective nature restoration and conservation measures. 相似文献
18.
Agricultural land-use changes in Europe have taken two opposing directions: towards agricultural intensification or land abandonment. While in the Mediterranean region land abandonment is a main cause of avian diversity decline, in northern Europe species diversity often increases with successional age. We examined the hypothesis that the biogeographic origin of the avifauna determines whether abandonment brings conservation benefits or detriment by studying the bird community of agricultural land in northern Spain, at the boundary of the Mediterranean and Eurosiberian regions. Using a successional gradient, we examined landscape-scale effects of agricultural abandonment on birds during the breeding and non-breeding seasons.The trend in avian diversity with successional stage differed little between Mediterranean and Eurosiberian species in winter. In the spring, however, there was an increase in diversity with stage in abandonment for Eurosiberian birds but not for Mediterranean species. Analysis of individual species showed a preference among Eurosiberian birds for more wooded habitats whereas Mediterranean birds preferred open areas and shrubland.The introduction of agricultural policies to geo-political units that do not coincide with eco-regions cannot be assumed to bring uniform conservation benefits. In the Mediterranean region, agricultural mosaics of low intensity cultivation maintain the highest diversity of priority bird species. Agricultural land abandonment should not be assumed to benefit conservation. 相似文献
19.
Efficiency of conservation shortcuts: an investigation with otters as umbrella species 总被引:1,自引:0,他引:1
The use of shortcuts is widespread in conservation practices to help ensure biodiversity conservation with minimal expenditures. An umbrella species is a species whose conservation confers protection to a large number of naturally co-occurring species. The aim of this study is to test the usefulness of the umbrella species concept for conservation management. As our umbrella, we chose a wide-ranging and flagship species, the European otter (Lutra lutra). Otters are widely distributed predators with numerous genera and species, so otter occurrence could virtually be used as “umbrella” in every freshwater habitat. To test the usefulness of the concept, we investigated whether an umbrella species might protect other species in the long term. We compared (1) bird and amphibian species richness in 1993 and in 2003 on nine sites where otters were monitored for 20 years, and (2) bird, amphibian and mollusc species richness between the previous sites and nine bio-equivalent sites where no otter occurrence has been detected for 20 years. The study was carried out for two spatial scales: total otter home range and core areas (most intensely exploited areas). Our results show that species richness was significantly different between years on sites inhabited by otters. However, we showed that biodiversity did not differ between pairs of bio-equivalent sites inhabited or deserted by otters, whatever the estimation method. Our results cast doubt on the validity of umbrella species use as an objective tool for conservation. However, the keystone functional role that otters could play in ecosystems might be an interesting way to reconsider the purpose of the umbrella species concept. 相似文献
20.
Scattered trees and small patches of vegetation among farmland are typical of rural landscapes throughout the world, often comprising a significant proportion of remaining habitats for native fauna. Insectivorous bats can use such isolated resources owing to the high mobility of most species, but little is known of the relationship between bats and tree density, or of the impact of incremental loss of trees in the landscape. Bats were surveyed at 30 sites in south-eastern Australia, in five habitat categories representing a range of tree densities from remnant woodland blocks (>35 trees/ha) to sparsely scattered trees (<1 tree/ha), and open paddocks devoid of trees. Sampling was undertaken by using harp traps and ultrasonic bat detectors. The abundance of potential arthropod prey was assessed by using light traps. Eleven species of insectivorous bats were recorded and bats were widespread in all habitat categories; all species were recorded around scattered trees. Overall activity, as revealed by detectors, did not differ significantly between the four treed categories, but in open paddocks there was a lower level of activity and a different community composition. However, a regression model revealed a significant quadratic relationship between activity of bats and tree density, with highest activity at 20-30 trees/ha. All species were recorded in open paddocks, but for eight of the ten species this represented <7% of their total activity recorded across all habitat categories. For six species, significant positive correlations were found between activity levels and the abundance of potential arthropod prey. In contrast to bat detectors, trapping results showed a significant difference in overall abundance of bats between wooded habitats, with decreased abundance as tree density declined. This study highlights the value of scattered trees as foraging habitat for bats, and emphasizes that, in rural land mosaics, such small and isolated habitat components have value for the conservation of biodiversity, and require greater recognition and protection. 相似文献