Butterfly diversity in Mediterranean islands and in Pentadaktylos <Emphasis Type="Italic">Pinus</Emphasis><Emphasis Type="BoldItalic"> </Emphasis><Emphasis Type="Italic">brutia</Emphasis> forests of Cyprus

We analysed the influence of contemporary geography on butterfly diversity for islands in the Mediterranean Basin. We found that island size and distance from the mainland has a significant effect on the number of species. We also used butterflies as an indicator group to identify the importance of forest habitats for biodiversity conservation in the island of Cyprus. To understand the relative importance of local vegetation characteristics of butterflies in the Pentadaktylos mountains transect counts were used to assess the abundance and butterfly diversity in two different forest types. A total of 1,602 butterflies and 23 species were recorded during this research. We observed highly significant effects of forest type on abundance and species richness of butterflies. For example, number of butterflies was significantly higher in old forest than young pine forest. Also, the abundance of endemic butterflies was highest in old forest habitats. Therefore, the survival of the majority of endemic butterflies in Cyprus may depend on conservation of old forests and their understorey plants.     

Estimating the consequences of land-use changes on butterfly diversity in a marginal agricultural landscape in Sweden

Abandonment of farming with the resultant increase in forest cover is one of the major threats to semi-natural grasslands in marginal agricultural areas. In Sweden, the loss of semi-natural grassland is a serious nature conservation problem since it is one of the most species-rich habitats. In this study, the consequences of grassland abandonment and afforestation on butterfly diversity and butterfly dispersal costs are estimated and used to compare three different future land-use scenarios for a marginal agricultural landscape in Sweden. Based on previous butterfly surveys on grasslands in the area, a relationship between land-use type and butterfly diversity was established. By comparing land-use maps of different scenarios, the number of suitable habitat patches and total suitable habitat patch area with low, medium and high butterfly diversity could be estimated. To obtain an indication of possible fragmentation effects, a least-cost analysis was used to compare travel costs of the butterflies between suitable habitat patches for the different scenarios. The results show that different land-use scenarios affect butterfly diversity and travel costs differently. In the extreme case scenario of cessation of full-time farming and a reduction in part-time farming, nearly all valuable butterfly habitats will vanish, since the most species-rich habitats lie in the periphery of the settlement and are expected to be abandoned and afforested first. If, on the other hand, grassland management is less reduced the effect of abandonment on butterflies depends very much on which areas continue to be managed. To preserve the most important grasslands for butterflies an active management strategy for the whole study area would be needed. While it seems relatively easy to identify the areas most important to conserve from a butterfly diversity perspective, it will be more difficult to find an optimal spatial solution that also minimises dispersal costs for butterflies.     

Low-Intensity Agricultural Landscapes in Transylvania Support High Butterfly Diversity: Implications for Conservation

European farmland biodiversity is declining due to land use changes towards agricultural intensification or abandonment. Some Eastern European farming systems have sustained traditional forms of use, resulting in high levels of biodiversity. However, global markets and international policies now imply rapid and major changes to these systems. To effectively protect farmland biodiversity, understanding landscape features which underpin species diversity is crucial. Focusing on butterflies, we addressed this question for a cultural-historic landscape in Southern Transylvania, Romania. Following a natural experiment, we randomly selected 120 survey sites in farmland, 60 each in grassland and arable land. We surveyed butterfly species richness and abundance by walking transects with four repeats in summer 2012. We analysed species composition using Detrended Correspondence Analysis. We modelled species richness, richness of functional groups, and abundance of selected species in response to topography, woody vegetation cover and heterogeneity at three spatial scales, using generalised linear mixed effects models. Species composition widely overlapped in grassland and arable land. Composition changed along gradients of heterogeneity at local and context scales, and of woody vegetation cover at context and landscape scales. The effect of local heterogeneity on species richness was positive in arable land, but negative in grassland. Plant species richness, and structural and topographic conditions at multiple scales explained species richness, richness of functional groups and species abundances. Our study revealed high conservation value of both grassland and arable land in low-intensity Eastern European farmland. Besides grassland, also heterogeneous arable land provides important habitat for butterflies. While butterfly diversity in arable land benefits from heterogeneity by small-scale structures, grasslands should be protected from fragmentation to provide sufficiently large areas for butterflies. These findings have important implications for EU agricultural and conservation policy. Most importantly, conservation management needs to consider entire landscapes, and implement appropriate measures at multiple spatial scales.     

Effects of land-use change on functional and taxonomic diversity of Neotropical bats

Human land-use changes are particularly extensive in tropical regions, representing one of the greatest threats to terrestrial biodiversity and a key research topic in conservation. However, studies considering the effects of different types of anthropogenic disturbance on the functional dimension of biodiversity in human-modified landscapes are rare. Here, we obtained data through an extensive review of peer-reviewed articles and compared 30 Neotropical bat assemblages in well-preserved primary forest and four different human-disturbed habitats in terms of their functional and taxonomic diversity. We found that disturbed habitats that are structurally less similar to primary forest (pasture, cropland, and early-stage secondary forest) were characterized by a lower functional and taxonomic diversity, as well as community-level functional uniqueness. These habitats generally retained fewer species that perform different ecological functions compared to higher-quality landscape matrices, such as agroforestry. According to functional trait composition, different bat ensembles respond differently to landscape change, negatively affecting mainly gleaning insectivorous bats in pasture, narrow-range species in cropland, and heavier animalivorous bats in secondary forest. Although our results highlight the importance of higher-quality matrix habitats to support elevated functional and taxonomic bat diversity, the conservation of bat species that perform different ecological functions in the mosaic of human-modified habitats also depends on the irreplaceable conservation value of well-preserved primary forests. Our study based on a pooled analysis of individual studies provides novel insights into the effects of different human-modified habitats on Neotropical bat assemblages.     

Does conservation on farmland contribute to halting the biodiversity decline?

Biodiversity continues to decline, despite the implementation of international conservation conventions and measures. To counteract biodiversity loss, it is pivotal to know how conservation actions affect biodiversity trends. Focussing on European farmland species, we review what is known about the impact of conservation initiatives on biodiversity. We argue that the effects of conservation are a function of conservation-induced ecological contrast, agricultural land-use intensity and landscape context. We find that, to date, only a few studies have linked local conservation effects to national biodiversity trends. It is therefore unknown how the extensive European agri-environmental budget for conservation on farmland contributes to the policy objectives to halt biodiversity decline. Based on this review, we identify new research directions addressing this important knowledge gap.     

Nature-oriented park use of satoyama ecosystems can enhance biodiversity conservation in urbanized landscapes

Satoyama is one of the semi-natural ecosystems in Japan. Traditional agricultural practices in satoyama provide preferable habitats for many species, thus, enhancing biodiversity. However, many satoyama ecosystems have been altered by agricultural intensification and rapid urbanization. Meanwhile, ageing and shrinking population has led to the abandonment of remaining satoyama ecosystems, resulting in their potential degradation. We argue that counteracting the abandonment of satoyama is particularly essential in urbanized landscapes because conserving its biodiversity would have a payoff for urban communities. We focused on nature-oriented park use of satoyama ecosystems, utilizing their original scenery, topography, water features, and vegetation. To evaluate the potential of nature-oriented park use for biodiversity conservation, we examined the differences in diversity and species composition of vascular plants and butterflies among three land-use types (agricultural-use, park-use, and abandoned sites) of satoyama ecosystems. Diversity of native plants and butterflies did not significantly differ between agricultural-use and park-use sites and that of native plants was significantly lower at abandoned sites than at agricultural-use sites. Although species composition of native plants at agricultural-use sites and park-use sites significantly differ, that of native butterflies did not. The efficacy of park use for biodiversity conservation, thus, depended on the taxa. Nonetheless, for striking a balance between the difficulty in maintaining agricultural use and accelerating satoyama abandonment, our study highlights the utility of park use as an alternative usage, contributing to biodiversity conservation. Balancing the wise use of satoyama in urbanized landscapes is a fundamental step toward the conservation of its biodiversity and human–nature interactions.

     

Monitoring Great Ape and Elephant Abundance at Large Spatial Scales: Measuring Effectiveness of a Conservation Landscape

Protected areas are fundamental to biodiversity conservation, but there is growing recognition of the need to extend beyond protected areas to meet the ecological requirements of species at larger scales. Landscape-scale conservation requires an evaluation of management impact on biodiversity under different land-use strategies; this is challenging and there exist few empirical studies. In a conservation landscape in northern Republic of Congo we demonstrate the application of a large-scale monitoring program designed to evaluate the impact of conservation interventions on three globally threatened species: western gorillas, chimpanzees and forest elephants, under three land-use types: integral protection, commercial logging, and community-based natural resource management. We applied distance-sampling methods to examine species abundance across different land-use types under varying degrees of management and human disturbance. We found no clear trends in abundance between land-use types. However, units with interventions designed to reduce poaching and protect habitats - irrespective of land-use type - harboured all three species at consistently higher abundance than a neighbouring logging concession undergoing no wildlife management. We applied Generalized-Additive Models to evaluate a priori predictions of species response to different landscape processes. Our results indicate that, given adequate protection from poaching, elephants and gorillas can profit from herbaceous vegetation in recently logged forests and maintain access to ecologically important resources located outside of protected areas. However, proximity to the single integrally protected area in the landscape maintained an overriding positive influence on elephant abundance, and logging roads – even subject to anti-poaching controls - were exploited by elephant poachers and had a major negative influence on elephant distribution. Chimpanzees show a clear preference for unlogged or more mature forests and human disturbance had a negative influence on chimpanzee abundance, in spite of anti-poaching interventions. We caution against the pitfalls of missing and confounded co-variables in model-based estimation approaches and highlight the importance of spatial scale in the response of different species to landscape processes. We stress the importance of a stratified design-based approach to monitoring species status in response to conservation interventions and advocate a holistic framework for landscape-scale monitoring that includes smaller-scale targeted research and punctual assessment of threats.     

坝上地区农田和恢复生境地表甲虫多样性

研究采用陷阱法对河北坝上崇礼县农田、禁牧草地及再造林地3种常见生境中地表甲虫进行了取样调查,分别从鞘翅目分科、步甲分种两个分类水平比较分析了不同生境中的生物多样性状况以评估生境恢复状况及其对生物多样性的影响,并探索在以生物多样性为指标评估生境恢复状况过程中,研究结论是否受分类水平的影响。结果显示,草地和林地具有较为相似鞘翅目和步甲的结构组成,但均显著不同于农田。农田较再造林地和禁牧草地具有更多的鞘翅目科数及步甲物种数,且均显著高于林地;农田中步甲群落的Fisher's α多样性指数也显著地高于林地,但鞘翅目分科水平上的Fisher's α多样性指数在各生境中没有差异。结果说明:(1)再造林和草地禁牧的生境修复活动在当前状态下对生物多样性恢复的作用尚不明显,仅是表现出促进了景观尺度上较高的Beta和Gamma多样性,而农田则在维持当地较高的生物多样性中扮演重要角色;(2)在鞘翅目分科和步甲科分种研究数据所反映的不同生境条件下的多样性和组成状况基本相同,因此在需要快速评估生境恢复状况且物种水平鉴定存在困难的时候,可以采用鞘翅目分科的数据替代指示生境恢复的状况并反映生境恢复对生物多样性影响的趋势,从而减少分类的难度并提高工作效率。但是物种水平的多样性状况更能显著反映生境间的差异。     

Asymmetric carabid beetle spillover between calcareous grasslands and coniferous forests

Central European calcareous grasslands are considered biodiversity hotspots, but are severely threatened by the change in land-use and by habitat fragmentation. Coniferous forests are typical adjacent habitats to calcareous grasslands, as abandoned calcareous grasslands are often afforested or develop into coniferous forests by succession. To investigate spillover between calcareous grasslands and coniferous forests, a total of 144 pitfall traps for carabid beetles were placed at three different distances (1, 5, 20 m) from the edge in both habitats at eight locations from April to late August. We found that both habitats had a distinct species assemblage and a decrease in spillover with increasing distance from the habitat edge into the adjacent habitat. Calcareous grasslands were more affected by spillover from the adjacent coniferous forests than vice versa because more forest specialists penetrated into calcareous grasslands than grassland specialists penetrated into coniferous forests. We conclude that spillover into small and isolated habitats can severely change species assemblages, which has to be considered in conservation measures. The protection of large sites with small edge-interior ratios can reduce negative effects on species assemblages in endangered calcareous grasslands.     

Taxonomic and functional approaches reveal different responses of ant assemblages to land-use changes

Land-use change is well documented to cause species loss. However, our understanding of the effects of land-use change on other aspects of biodiversity is still limited. We evaluated if different land-use changes (Eucalyptus plantation and planted pasture) affect ant species and functional groups in similar ways across three Cerrado vegetation types (grassland, savanna and savanna-forest). We found that ant species and functional responses differed with land-use change in relation to frequency of occurrence and habitat specificity and fidelity. Land-use change affected species frequency of occurrence but not functional groups, indicating that species are more sensitive than functional groups to habitat transformation. Native habitats had different indicator species and functional groups compared with converted habitats. However, we did not find functional group indicators of converted habitats in any vegetation type; indicating that there is no specificity and fidelity of functional group to converted habitats and that such an approach is less sensitive to land-use changes. In savanna and savanna-forest, species and functional groups showed the same response in relation to composition with differences between native and converted habitats. Thus, functional groups will be lost when ant species are lost. In grasslands, functional group composition was similar between native and converted habitats indicating a turnover of species within functional groups. We demonstrate that both Eucalyptus plantation and planted pasture affect ant species and functional groups in different ways, with negative impacts both taxonomically and less so functionally. Therefore, we show that the two aspects of biodiversity can respond independently to land-use changes and, hence, the importance of using both taxonomic and functional group approaches to evaluate the effects of land-use change on biodiversity in savanna systems.     

Conservation priority of Italian Alpine habitats: a floristic approach based on potential distribution of vascular plant species

In the European Union, the Directive 92/43/EEC defines a number of species and habitats of community interest that are worthy to be preserved because in danger to disappear or because they are representative of the different European bio-geographical regions. In the light of the limited economic resources generally allocated to conservation efforts, there is the necessity to prioritise conservation actions in order to avoid deterioration of protected areas. To this aim, in the present study the most representative habitats of the Italian Alps are compared on the basis of vascular plant biodiversity and a conservation priority index is proposed for each habitat taking into account the potential distribution of 252 threatened vascular plant species. Rocky slopes, screes and alpine grasslands resulted to have the greatest percentage of endemic plant species so reflecting the general distributional pattern of endemic plant species at high altitudes in Eurasian mountains. The relationship between the conservation priority index and the corresponding habitat extent within the Natura 2000 network suggests that peatlands, arid grasslands, wet meadows and freshwater habitats deserve a higher priority in conservation actions. Although vascular plant biodiversity is not necessarily a surrogate of overall biodiversity of Alpine habitats, the results here reported can be used as an initial reference framework for prioritising conservation actions, so as to accomplish the provisions of Article 6 of Habitats Directive.     

Changing conservation strategies in Europe: a framework integrating ecosystem services and dynamics

Protecting species and their habitats through the designation and management of protected areas is central to present biodiversity conservation efforts in Europe. Recent awareness of the importance of ecosystem dynamics in changing environments and of human needs for the sustainable provision of ecosystem services expose potential weaknesses in current European conservation management strategies and policy. Here we examine these issues in the light of information gained from reviews, workshops, interviews and discussions undertaken within the RUBICODE project. We present a new conceptual framework that joins conventional biodiversity conservation with new requirements. The framework links cultural and aesthetic values applied in a static environment to the demands of dynamic ecosystems and societal needs within social–ecological systems in a changing Europe. We employ this framework to propose innovative ways in which ecosystem service provision may be used to add value to traditional conservation approaches by supporting and complementing present European biodiversity conservation strategy and policy while remaining within the guidelines of the Convention on Biological Diversity.     

The potential of military training areas for bird conservation in a central European landscape

European biodiversity has suffered from serious declines during the past few decades, with alterations of land use practices resulting in a loss of fine-scale habitat heterogeneity being a dominant driver. This heterogeneity was maintained by extensive landscape management, which has gradually been replaced by either intensive exploitation or land abandonment. It has been suggested that military training can generate habitat heterogeneity that may support the existence of species of conservation concern, but studies rigorously testing the real importance of military training areas for biodiversity are lacking. Here we address this issue by analyses of two datasets. First, we compared land cover classes between all large military training areas (MTAs) and surrounding control areas (CAs) of the same size in the Czech Republic using multivariate redundancy analysis. We found that the difference in land cover between MTAs and CAs was significant and represented the strongest gradient in land cover classes: from various farmland and artificial habitats typical for CAs to forest and scrubland-grassland mosaic typical for MTAs. Second, we selected one of these areas and compared bird species richness between the MTA and the nearby CA using generalized linear mixed effects models. We found that the number of species of conservation concern was significantly higher in the MTA than in the CA. With respect to habitats, bird species richness was significantly higher in the MTA than in the CA for open habitats, but not for forest habitats. Our results are thus consistent with the view that military training creates areas that are different from the surrounding landscape in terms of land cover, and that this difference translates to a suitability for species of conservation concern. It is remarkable that the positive influence of military training is confined to open habitats, which are subject to the most intensive military activities and also suffer the highest degree of deterioration in European landscapes.     

云南高黎贡山地区蝴蝶群落多样性

位于滇西北的高黎贡山是全球生物多样性研究和保护的热点地区之一, 然而该地区昆虫多样性缺乏系统调查和总结。本研究聚焦蝴蝶类群, 考虑该区域高山峡谷特点, 结合海拔梯度、生境类型和季节变化, 采用样线法调查、分析蝴蝶物种多样性及群落结构变化。结果显示: 共观测记录到蝴蝶2,055只, 隶属于5科85属151种, 在历史记录上新增27种, 使该地区已知蝴蝶种类达488种; 其中蛱蝶科物种多样性最高, 灰蝶科次之, 凤蝶科最低。蝴蝶群落多样性分析结果表明: 中海拔1,000-2,000 m区域种类丰富、多样性指数最高; 低海拔区蝴蝶分布明显聚集, 并且与高海拔地区空间上分离, 少有重叠。该地区不同生境中蝴蝶的种类及数量差异也较大, 物种数及多样性指数在自然保护区最高、边缘交错带居中及农业种植区最低。此外, 蝴蝶的种类和数量也存在季节差异, 春季调查到的个体数少, 夏季观察到的物种数少, 两年秋季调查到的物种丰富度、多样性均高, 但存在季节内变化。总之, 高黎贡山地区不同海拔、生境、季节间和季节内蝴蝶群落组成有自身特点, 共存物种有限, 蝴蝶群落相似性低。综合评估分布于该地区的蝴蝶保护种类, 包括易危种17种、近危种50种, 有国家二级保护蝴蝶3种。本研究弄清了高黎贡山地区蝴蝶的物种本底, 并调查获得其多样性随海拔、生境和季节变化的模式, 为加强区域物种多样性监测、保护生物多样性提供了科学依据。     

Climate and land-use interactively shape butterfly diversity in tropical rainforest and savanna ecosystems of southwestern China

Human-induced habitat conversion and degradation, along with accelerating climatic change, have resulted in considerable global biodiversity loss. Nevertheless, how local ecological assemblages respond to the interplay between climate and land-use change remains poorly understood. Here, we examined the effects of climate and land-use interactions on butterfly diversity in different ecosystems of southwestern China. Specifically, we investigated variation in the alpha and beta diversities of butterflies in different landscapes along human-modified and climate gradients. We found that increasing land-use intensity not only caused a dramatic decrease in butterfly alpha diversity but also significantly simplified butterfly species composition in tropical rainforest and savanna ecosystems. These findings suggest that habitat modification by agricultural activities increases the importance of deterministic processes and leads to biotic homogenization. The land-use intensity model best explained species richness variation in the tropical rainforest, whereas the climate and land-use intensity interaction model best explained species richness variation in the savanna. These results indicate that climate modulates the effects of land-use intensity on butterfly alpha diversity in the savanna ecosystem. We also found that the response of species composition to climate varied between sites: specifically, species composition was strongly correlated with climatic distance in the tropical rainforest but not in the savanna. Taken together, our long-term butterfly monitoring data reveal that interactions between human-modified habitat change and climate change have shaped butterfly diversity in tropical rainforest and savanna. These findings also have important implications for biodiversity conservation under the current era of rapid human-induced habitat loss and climate change.     

Priorities for biodiversity monitoring in Europe: A review of supranational policies and a novel scheme for integrative prioritization

Trends and status of species and habitats need to be measured to assess whether global biodiversity policy targets have been achieved. However, it is impossible to monitor all species and habitats with a justifiable effort. Therefore, it is critical to prioritize the monitoring of specific biodiversity components. Priorities must be linked to key nature conservation policies to ensure that monitoring efforts are relevant to policy needs, achieve maximum impact, and obtain governmental support. Here we discuss priority setting in biodiversity monitoring in view of monitoring obligations and priorities in supranational biodiversity legislation and policies in Europe and assess overlaps in priorities among policies. While most supranational biodiversity regulations require monitoring of biodiversity, obligations are legally enforceable only for the Nature Directives, the Water Framework Directive, and the Marine Strategy Framework Directive of the European Union. Of the assessed international conventions and other relevant policy instruments about 50% explicitly designate priority species and most focus on vertebrates. Lower emphasis is given to habitats and geographical priorities are even less pronounced. Also, an overarching system for monitoring prioritization is still missing. Our prioritization system is based on three main criteria: (1) legal requirement for reporting, (2) wording used to define priority or importance, and (3) inclusion in lists that indicate importance of monitoring due to e.g. threats or relevance of a region for a species. Our system contains five main priority levels, within which an additional division differentiates priorities according to national/European responsibility criteria. Based on this system, we provide recommendations for allocating species and habitats enlisted by the reviewed policy tools to explicit non-overlapping priority levels. Our approach will facilitate synergies between monitoring activities for different policy needs, and contribute to alleviate the notorious resource shortage for biodiversity monitoring.     

Relative importance of habitat and landscape scales on butterfly communities of urbanizing areas

Agricultural decline and urbanization entail rapid alterations of the patterns of organization of rural landscapes in Europe. The spread of the urban footprint to the adjacent countryside contributes to the development of new anthropogenic ecosystems in formerly rural hinterlands. In this study, butterflies are considered as biological indicators of these rapid environmental changes. Our purpose is to better understand changes in biodiversity related to the evolution of available habitats in a mutating landscape. In this study, we investigate butterfly communities of four land-use types (fallow lands, gardens, vineyards, woodlands) within different landscape contexts. Our results reveal that variations in structure and functional composition of these communities are related to different levels of human disturbance at both landscape scale and habitat scale.     

Impacts of land-use on West African savanna vegetation: a comparison between protected and communal area in Burkina Faso

Biodiversity matters in many aspects for human well-being by providing timber and non-timber products. The most important ecosystems providing these products in West Africa are savannas. In the context of land-use changes, there is an urgent need to understand the impact of land-use on savanna vegetation and biodiversity. This study assesses the impact of land-use on savannas by comparing protected and communal areas. Vegetation relevés were performed in the W National Park and its surrounding communal area in Burkina Faso. Vegetation types were established using ordination and clustering methods. We analyzed to find which environmental factors determine the occurrence of the vegetation types and whether land-use has a specific effect on diversity of vegetation types occurring in both areas. Furthermore, we tested the effect of land-use on vegetation structure and the occurrence of life forms and highly valued tree species. Our results reveal five vegetation types occurring in both areas. Elevation and soil characteristics played the most important role for the occurrence of the vegetation types. Land-use had an effect on vegetation structure, diversity, and the occurrence of life form and highly valued species. Our findings suggest that traditional human land-use does not automatically lead to loss of species and degradation of savanna habitats and that combination of communal and protected areas may be of great importance for the conservation of broad spectrum of biodiversity. Our study demonstrates the complexity of land-use impact on biodiversity patterns and provides insights on what kind of management activities may be most appropriate in both areas.     

Conserving butterflies in fragmented plantation forests: are edge and interior habitats equally important?

Edge effects are increasing in forest-dominated landscapes worldwide, due to increased fragmentation by other land uses. Understanding how species respond to edges is therefore critical to define adequate conservation measures. We compared the relative importance of interior and edge habitats for butterflies in a landscape composed of even-aged pine plantations interspersed with semi-natural habitats. Butterfly assemblages were surveyed simultaneously at the edge and the interior of 68 patches belonging to four main habitat types: herbaceous firebreaks, clearcuts and young pine stands, older pine stands, and deciduous woodlands. Butterfly species richness was higher at edges than in interior habitats, especially for pine stands. Assemblage composition differed significantly between edge and interior habitats, except for firebreaks. Of the 23 most abundant butterfly species, seven were significantly more abundant in one or all edge habitat types, five in interior habitats, and 11 species showed no edge-interior preference. Modelling the presence of individual species in edge habitats revealed the importance of habitat variables such as the abundance of nectar and host-plants, but also of the abundance of the same species in the adjacent interior habitat. Moreover, our results suggest that most species use several, different habitat types to find supplementary or complementary resources, including micro-climatic refuges to escape hot temperatures during summer. The use of adjacent edge and interior habitats by butterflies is probably a key process in such mosaic landscapes and underlines the importance of landscape heterogeneity for butterfly conservation.     

城市公园和郊区公园生物多样性评估的指标

随着城市化进程的加快,城市的生物多样性不可避免地受到城市化的各种影响,城市及其郊区的生物多样性保护越来越受到人们的重视。城市公园与郊区公园中往往具有高度多样化的生境,并保存着某些自然植被片段和动物物种,那里的生物多样性较高。可见,在城市和郊区的生物多样性保护中,公园生物多样性的保护是一个非常关键的环节,而对其生物多样性的评估又是有效保护的基础。目前,我国生物多样性评估方面的研究工作多集中于物种水平,而对生境的研究较少,但实践证明,保护生境比保护物种更为重要。本文介绍了比利时学者Hermy & Cornelis在比利时西佛兰德省的Loppem市立公园的保护实践中构建的一种对城市公园和郊区公园中的生物多样性进行评估的方法。该方法从两个方面展开：生境多样性和物种多样性。在生境水平上,首先对各种生境单元进行分类,这些单元被分为面状、线状和点状要素。针对每种要素,分别计算了Shannon-Wiener多样性指数和饱和度指数。饱和度指数是实际的多样性指数与最大可能的多样性指数之比。在物种水平上,使用了物种数、Shannon-Wiener多样性指数和饱和度指数来评估公园中的高等植物、蝴蝶、两栖动物和饲养的鸟类等物种。这样,就获得了20个生物多样性指标,根据这些指数就可以对Loppem市立公园内的生物多样性进行评估。结合我国生物多样性评估工作的实际要求,文章最后对上述方法进行了讨论,指出该方法对我国公园的生物多样性评估工作具有借鉴意义,但在运用时各地需要结合本地的实际情况。