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1.
Abstract:  Many endangered species depend on certain types of agricultural or other forms of human land use. To conserve such species, schemes are set up in which land users receive payments for voluntarily managing their land in a biodiversity-enhancing manner. We developed a model-based framework for designing cost-effective payment schemes that generate spatiotemporal habitat heterogeneity to maximize the survival of multiple species under budget constraints. The framework integrates ecological and economic knowledge and consists of the derivation of an ecological benefit function and a budget function that are then combined to determine the cost-effective degree of spatiotemporal habitat heterogeneity. The ecological benefit function considers the timing of conservation measures, the induced habitat dynamics, and different degrees of substitutability among species. The budget function considers that the conservation agency may lack information about land users' individual conservation costs and personal attitudes and that land users can choose among different conservation measures. We applied the framework to a case study of grassland management, where the survival of three endangered species protected by the EU Habitats Directive depends on different types of land use. The lack of information available to the agency and the choice options of land users reduced the amount of conservation that can be financed with a given budget. Neglecting such findings may lead to an overestimation of the benefits of conservation programs.  相似文献   

2.
Migratory waterfowl depend on habitat networks at local, national and international scales for their survival. Coastal habitats are key areas for many waterfowl. Different species use different biotopes and in different places, so overall many parts of the coastal resource are important. As well as national conservation efforts, waterfowl conservation is increasingly focussed worldwide on collaborative international conservation, catalysed by several measures e.g. the Ramsar Convention, the EC Conservation of Wild Birds Directive, and the Bonn Convention Agreement on the Conservation of African/Eurasian Migratory Waterbirds. Several international conservation plans are under development for single species, but a more effective approach may be to develop plans, for assemblages of migratory birds with similar habitat requirements. All such plans must incorporate future sustainable use of the habitats on which the birds depend. Yet migratory bird and coastal habitat conservation is still often approached separately, despite the two being now closely linked to the development of the Natura 2000 site network in the European Community. Implementing the 1992 EC Habitats Directive requires the selection of coastal habitat sites for designation, set in national and international contexts of resource distribution. International coastal habitat inventories are needed to underpin this process. Combining such inventories with assessment of the flyway habitat requirements of waterfowl species and assemblages offers great potential for identifying international coastal habitat networks that meet the objectives of both habitat and migratory waterfowl conservation.  相似文献   

3.
Abstract:  The Iberian Peninsula harbors about 50% of European plant and terrestrial vertebrate species and more than 30% of European endemic species. Despite the global recognition of its importance, the selection of protected areas has been ad hoc and the effectiveness of such choices has rarely been assessed. We compiled the most comprehensive distributional data set of Iberian terrestrial plant and vertebrate species available to date and used it to assess the degree of species representation within existing protected areas. Existing protected areas in Spain and Portugal reasonably represented the plant and animal species we considered (73–98%). Nevertheless, species of some groups (amphibians, reptiles, birds, and gymnosperms) did not accumulate in protected areas at a rate higher than expected by chance ( p > 0.05). We determined that to conserve all vertebrate and plant species in the Iberian Peninsula, at least 36 additional areas are needed. Selection of additional areas for conservation would be facilitated if such areas coincided with sites of community importance (SCI) designated under the European Commission Habitats Directive. Additional areas required for full representation of the selected plant and animal species all coincide with SCI in Spain. Nevertheless, the degree of coincidence varies between 0.3% and 74.6%, and there is a possibility that important areas for conservation occur outside the SCI. Our results support the view that current SCI can be used for prioritization of areas for conservation, but a systematic reevaluation of conservation priorities in Spain and Portugal would be necessary to ensure that effective conservation of one of European's most important biodiversity regions is achieved.  相似文献   

4.
The South American dry Chaco is a mosaic of woody vegetation and grasslands with high deforestation rates in recent decades. Considering forests and grasslands as the main natural habitats, we assessed the trade-offs between bird populations and agricultural production to compare the potential consequences of different land use strategies (‘sharing’, ‘sparing’, and intermediate) for populations of bird species sensitive to agriculture, while attaining a regional production target. We evaluated how populations responded to scenarios with different proportions of forest and grasslands, considering three reference states (100% forest, 80:20% and 50:50% forest and grasslands, respectively); and scenarios capable of meeting three after-farming scenarios, with land destined to reach a regional production target with three variations of forest:grasslands within spared land. We fitted curves to relate bird abundance to agricultural yield along a gradient of meat production intensity; and we classified bird species as ‘losers’ (if their populations were lower than the baseline population in the reference state, at any level of production) and ‘winners’ (if their current populations were higher than the baseline population). At the ‘current’ (c. 2010) level of regional agricultural production, we found a similar number of loser species maximized by land-sparing and land-sharing strategies; while intermediate strategies were the least favourable to balance production and bird populations. Under the most probable scenarios of increases in regional meat production, most loser bird species populations were maximized by a land-sparing strategy, suggesting that if meat production targets are going to increase in the region, this can be more efficiently achieved by combining well-protected forests and grasslands, and high-yielding mechanized agriculture (e.g. soybean). Our results highlight the importance of assessing all the important natural habitats (e.g. forests and grasslands) of a region to explore conservation strategies at a regional scale.  相似文献   

5.
Europe is a region of relatively high population density and productive agriculture subject to substantial government intervention under the Common Agricultural Policy (CAP). Many habitats and species of high conservation interest have been created by the maintenance of agricultural practices over long periods. These practices are often no longer profitable, and nature conservation initiatives require government support to cover the cost for them to be continued. The CAP has been reformed both to reduce production of agricultural commodities at costs in excess of world prices and to establish incentives for landholders to adopt voluntary conservation measures. A separate nature conservation policy has established an extensive series of protected sites (Natura 2000) that has, as yet, failed to halt the loss of biodiversity. Additional broader scale approaches have been advocated for conservation in the wider landscape matrix, including the alignment of agricultural and nature conservation policies, which remains a challenge. Possibilities for alignment include further shifting of funds from general support for farmers toward targeted payments for biodiversity goals at larger scales and adoption of an ecosystem approach. The European response to the competing demands for land resources may offer lessons globally as demands on rural land increase.  相似文献   

6.
The Convention on Biological Diversity has catalyzed worldwide awareness of threats to biological diversity and stimulated global conservation strategies. These have led to national and international legislation and have generated debate about the most effective conservation actions. Under the EU Habitats Directive, all member states are obliged to establish a system for strict protection of species listed in Annex IV(a), which includes all bats. In England, this obligation has resulted in legislation that allows for derogation from strict protection under license, provided activities are undertaken to mitigate any potential negative effects on bat numbers. We used an evidence‐based approach to assess the cost‐effectiveness of mitigation strategies and the English bat‐derogation licensing process as a whole. We analyzed data from 389 bat derogation licenses issued in England from 2003 to 2005 relating to 1776 roosts and 15 species to determine the nature and extent of development and mitigation activities and their effects on bats. Overall the effects of licensed activities on roosts were negative. Despite the level of protection afforded to bats, the majority (68%) of roosts for which derogation licenses were issued were destroyed. There were species‐specific differences in the probability of roosts being destroyed, and impacts on roosts did not reflect a species’ conservation status. Information provided by licensees was inadequate and inconsistent. Most licensees (67%) failed to submit postdevelopment reports, and postdevelopment monitoring was conducted at only 19% of sites. Despite a minimum of £4.13 million spent on mitigation structures for bats from 2003 to 2005, it was unclear whether the licensing process meets EU obligations. On the basis of our results, we believe there is a need to overhaul the licensing process, to establish a comprehensive, standardized postdevelopment monitoring system, and to demonstrate that mitigation is commensurate with Britain's legal obligations. Mitigando el Efecto del Desarrollo sobre los Murciélagos en Inglaterra con Licencias de Derogación  相似文献   

7.
Obligate Cave Fauna of the 48 Contiguous United States   总被引:7,自引:0,他引:7  
Abstract: We assembled a list of obligate cave-dwelling species and subspecies, their county distribution, and their provisional global conservation rank. A total of 927 species and 46 additional subspecies in 96 families exclusively from cave and associated subterranean habitats have been described in the 48 contiguous states of the United States. The terrestrial (troglobitic) species are concentrated in northeast Alabama (especially Jackson County), with other concentrations in Kentucky, Texas, Virginia, and West Virginia. Only 23 counties, comprising less than 1% of the land area of the 48 contiguous states, account for over 50% of the terrestrial species and subspecies. The aquatic (stygobitic) species are concentrated in Hays County, Texas, with other concentrations in Florida, Oklahoma, Texas, Virginia, and West Virginia. Only 18 counties, comprising less than 1% of the land area, account for over 50% of the aquatic species and subspecies. Endemism is high, with 54% of the species known from a single county. Approximately 95% of the species are listed by The Nature Conservancy as vulnerable or imperiled in the United States. These cave species comprise 50% of all vulnerable or imperiled species listed in databases of the Natural Heritage Program. Less than 4% of these subterranean species have federal status. Conservation can best be accomplished through habitat protection, which must include protection of the associated surface habitat.  相似文献   

8.
Spatial and Seasonal Patterns of Bird Communities in Italian Agroecosystems   总被引:2,自引:0,他引:2  
Abstract:  Despite agricultural landscapes covering almost 60% of the total land area of Italy, knowledge of the effects of agriculture and its intensification on bird communities is still scarce. I analyzed the effects of land uses on bird diversity and community structure in different farmland habitats of lowland northwestern Italy. I surveyed breeding and overwintering birds with a hierarchically nested sampling design and used generalized linear and mixed models to investigate the relationships between the diversity and abundance of birds and habitat or landscapes attributes. The effects of agriculture on α avian diversity varied with season and spatial scale, whereas nonagricultural habitats (long-term fallows or woodlands) had a generally positive effect that was constant throughout time and space. As the amount of woodland habitat increased, spatial turnover (β diversity) of breeding birds decreased. Arable landscapes supported low levels of avian diversity throughout the year but were favored by emblematic farmland birds that have declined severely in Europe and in the study area. Farmland birds (40% of which are experiencing population declines) were more abundant or foraged more frequently in the less-disturbed habitat types such as fallows, grasslands, and winter stubbles and tended to avoid the prevailing cultivations (maize, vineyard, and wheat). Landscape simplification, the expansion of maize cultivation, winter plowing practices, and the conversion of highly diverse grasslands to tilled lands are likely to be responsible for the local decline of most farmland species (Skylark [Alauda arvensis ], Starling [Sturnus vulgaris ], buntings [Emberiza spp.], and wagtails [Motacilla spp.]) and for the increase of birds that are turning into agricultural pests (Hooded Crow [Corvus corone cornix ]).  相似文献   

9.
Habitats vary considerably in the level of invasion (number or proportion of alien plant species they contain), which depends on local habitat properties, propagule pressure, and climate. To determine the invasibility (susceptibility to invasions) of different habitats, it is necessary to factor out the effects of any confounding variables such as propagule pressure and climate on the level of invasion. We used 20 468 vegetation plots from 32 habitats in the Czech Republic to compare the invasibility of different habitats. Using regression trees, the proportion of alien plants, including archaeophytes (prehistoric to medieval invaders) and neophytes (recent invaders), was related to variables representing habitat properties, propagule pressure, and climate. The propagule pressure was expressed as the proportion of surrounding urban and industrial or agricultural land, human population density, distance from a river, and history of human colonization in the region. Urban and industrial land use had a positive effect on the proportion of both archaeophytes and neophytes. Agricultural land use, higher population density, and longer history of human impact positively affected the proportion of archaeophytes. Disturbed human-made habitats with herbaceous vegetation were most invaded by both groups of aliens. Neophytes were also relatively common in disturbed woody vegetation, such as broad-leaved plantations, forest clearings, and riverine scrub. These habitats also had the highest proportion of aliens after removing the effect of propagule pressure and climate, indicating that they are not only the most invaded, but also most invasible. These habitats experience recurrent disturbances and are rich, at least temporarily, in available nutrients, which supports the hypothesis that fluctuating resources are the major cause of habitat invasibility. The least invaded habitats were mires and alpine-subalpine grasslands and scrub. After removing the effect of propagule pressure and climate, some habitats actually invaded at an intermediate level had very low proportions of aliens. This indicates that these habitats (e.g., dry, wet, and saline grasslands, base-rich fens, and broad-leaved deciduous woodlands) are resistant to invasion.  相似文献   

10.
Abstract: Management of amphibian populations to reverse recent declines will require defining high-quality habitat for individual species or groups of species, followed by efforts to retain or restore these habitats on the landscape. We examined landscape-level habitat relationships for frogs and toads by measuring associations between relative abundance and species richness based on survey data derived from anuran calls and features of land-cover maps for Iowa and Wisconsin. The most consistent result across all anuran guilds was a negative association with the presence of urban land. Upland and wetland forests and emergent wetlands tended to be positively associated with anurans. Landscape metrics that represent edges and patch diversity also had generally positive associations, indicating that anurans benefit from a complex of habitats that include wetlands. In Iowa the most significant associations with relative abundance were the length of the edge between wetland and forest ( positive) and the presence of urban land (negative). In Wisconsin the two most significant associations with relative abundance were forest area and agricultural area ( both positive). Anurans had positive associations with agriculture in Wisconsin but not in Iowa. Remnant forest patches in agricultural landscapes may be providing refuges for some anuran species. Differences in anuran associations with deep water and permanent wetlands between the two states suggest opportunities for management action. Large-scale maps can contribute to predictive models of amphibian habitat use, but water quality and vegetation information collected from individual wetlands will likely be needed to strengthen those predictions. Landscape habitat analyses provide a framework for future experimental and intensive research on specific factors affecting the health of anurans.  相似文献   

11.
One speaks of ecological substitutes when an introduced species performs, to some extent, the ecosystem function of an extirpated native species. We suggest that a similar case exists for habitats. Species evolve within ecosystems, but habitats can be destroyed or modified by natural and human‐made causes. Sometimes habitat alteration forces animals to move to or remain in a suboptimal habitat type. In that case, the habitat is considered a refuge, and the species is called a refugee. Typically refugee species have lower population growth rates than in their original habitats. Human action may lead to the unintended generation of artificial or semiartificial habitat types that functionally resemble the essential features of the original habitat and thus allow a population growth rate of the same magnitude or higher than in the original habitat. We call such areas substitution habitats and define them as human‐made habitats within the focal species range that by chance are partial substitutes for the species’ original habitat. We call species occupying a substitution habitat adopted species. These are 2 new terms in conservation biology. Examples of substitution habitats are dams for European otters, wheat and rice fields for many steppeland and aquatic birds, and urban areas for storks, falcons, and swifts. Although substitution habitats can bring about increased resilience against the agents of global change, the conservation of original habitat types remains a conservation priority.  相似文献   

12.
A comprehensive list of 1068 typical littoral plant species and subspecies has been composed. They are considered endemic in a wide sense and are subdivided into widespread, transregional, regional and local endemics, the latter three categories being considered as endemics s.s. For each taxon the distribution, habitat preference, endemic status and conservation status are given. The list, which is available upon request, is summarized in a number of figures and tables, from which it appears that 61% of all species are endemics s.s., that ca. 30% of all species are dune and beach species and another nearly 30% are maritime rock species. Species of wet habitats are concentrated in northern and northwestern Europe, dune species in western and southwestern Europe, western Mediterranean and Black Sea. The conservation status of most species is indicated; 37% is considered threatened. It is concluded that the Bern Convention and the European Habitat Directive offer an entirely insufficient framework for effective conservation action. It is suggested to take the present list as a starting point for a geographical/taxonomical/ecological data base of European coastal endemics.  相似文献   

13.
Biodiversity offsets are intended to achieve no net loss of biodiversity due to economic and human development. A variety of biodiversity components are addressed by offset policies. It is required that loss of protected species due to development be offset under the EU Habitats and Birds Directives in Europe. We call this type of offset a species‐equality offset because the offset pertains to the same species affected by the development project. Whether species equality can be achieved by offset design is unknown. We addressed this gap by reviewing derogation files (i.e., specific files that describe mitigation measures to ensure no net loss under the EU Habitats and Birds Directives) from 85 development projects in France (2009–2010). We collected information on type of effect (reversible vs. irreversible) and characteristics of affected and offset sites (i.e., types of species, total area). We analyzed how the type of effect and the affected‐site characteristics influenced the occurrence of offset measures. The proportion of species targeted by offset measures (i.e., offset species) increased with the irreversibility of the effect of development and the conservation status of the species affected by development (i.e., affected species). Not all effects on endangered species (International Union for Conservation of Nature Red List) were offset; on average, 82% of affected species would be offset. Twenty‐six percent of species of least concern were offset species. Thirty‐five percent of development projects considered all affected species in their offset measures. Species richness was much lower in offset sites than in developed sites even after offset proposals. For developed areas where species richness was relatively high before development, species richness at offset sites was 5–10 times lower. The species‐equality principle appears to have been applied only partially in offset policies, as in the EU directives. We suggest the application of this principle through offsets is highly important for the long‐term conservation of biodiversity in Europe. Compensaciones y Conservación de las Especies de las Directivas de Hábitats y Aves de la UE  相似文献   

14.
Persistence of Forest Birds in the Costa Rican Agricultural Countryside   总被引:8,自引:1,他引:8  
Abstract:  Understanding the persistence mechanisms of tropical forest species in human-dominated landscapes is a fundamental challenge of tropical ecology and conservation. Many species, including more than half of Costa Rica's native land birds, use mostly deforested agricultural countryside, but how they do so is poorly known. Do they commute regularly to forest or can some species survive in this human-dominated landscape year-round? Using radiotelemetry, we detailed the habitat use, movement, foraging, and nesting patterns of three bird species, Catharus aurantiirostris , Tangara icterocephala , and Turdus assimilis , by obtaining 8101 locations from 156 individuals. We chose forest birds that varied in their vulnerability to deforestation and were representative of the species found both in forest and human-dominated landscapes. Our study species did not commute from extensive forest; rather, they fed and bred in the agricultural countryside. Nevertheless, T. icterocephala and T. assimilis , which are more habitat sensitive, were highly dependent on the remaining trees. Although trees constituted only 11% of land cover, these birds spent 69% to 85% of their time in them. Breeding success of C. aurantiirostris and T. icterocephala in deforested habitats was not different than in forest remnants, where T. assimilis experienced reduced breeding success. Although this suggests an ecological trap for T. assimilis , higher fledgling survival in forest remnants may make up for lower productivity. Tropical countryside has high potential conservation value, which can be enhanced with even modest increases in tree cover. Our findings have applicability to many human-dominated tropical areas that have the potential to conserve substantial biodiversity if appropriate restoration measures are taken.  相似文献   

15.
Globally, agriculture is the greatest source of threat to biodiversity, through both ongoing conversion of natural habitat and intensification of existing farmland. Land sparing and land sharing have been suggested as alternative approaches to reconcile this threat with the need for land to produce food. To examine which approach holds most promise for grassland species, we examined how bird population densities changed with farm yield (production per unit area) in the Campos of Brazil and Uruguay. We obtained information on biodiversity and crop yields from 24 sites that differed in agricultural yield. Density–yield functions were fitted for 121 bird species to describe the response of population densities to increasing farm yield, measured in terms of both food energy and profit. We categorized individual species according to how their population changed across the yield gradient as being positively or negatively affected by farming and according to whether the species’ total population size was greater under land‐sparing, land‐sharing, or an intermediate strategy. Irrespective of the yield, most species were negatively affected by farming. Increasing yields reduced densities of approximately 80% of bird species. We estimated land sparing would result in larger populations than other sorts of strategies for 67% to 70% of negatively affected species, given current production levels, including three threatened species. This suggests that increasing yields in some areas while reducing grazing to low levels elsewhere may be the best option for bird conservation in these grasslands. Implementing such an approach would require conservation and production policies to be explicitly linked to support yield increases in farmed areas and concurrently guarantee that larger areas of lightly grazed natural grasslands are set aside for conservation.  相似文献   

16.
Most examples that support the substitution‐habitat hypothesis (human‐made habitats act as substitutes of original habitat) deal with birds and mammals. We tested this hypothesis in 14 amphibians by using percentage occupancy as a proxy of habitat quality (i.e., higher occupancy percentages indicate higher quality). We classified water body types as original habitat (no or little human influence) depending on anatomical, behavioral, or physiological adaptations of each amphibian species. Ten species had relatively high probabilities (0.16–0.28) of occurrence in original habitat, moderate probability of occurrence in substitution habitats (0.11–0.14), and low probability of occurrence in refuge habitats (0.05–0.08). Thus, the substitution–habitat hypothesis only partially applies to amphibians because the low occupancy of refuges could be due to the negligible human persecution of this group (indicating good conservation status). However, low occupancy of refuges could also be due to low tolerance of refuge conditions, which could have led to selective extinction or colonization problems due to poor dispersal capabilities. That original habitats had the highest probabilities of occupancy suggests amphibians have a good conservation status in the region. They also appeared highly adaptable to anthropogenic substitution habitats.  相似文献   

17.
Empirical evidence from many regions suggests that most species would be least negatively affected if human food demand were met through high-yield agricultural production and conservation of nonfarm ecosystems (land sparing), rather than through wildlife-friendly farming over a larger area (land sharing). However, repeated glaciation and a long history of agriculture may lead to different results in regions such as western Europe. We compared the consequences of land sparing and land sharing on breeding bird species in 2 lowland regions of England, The Fens, with 101 species, and Salisbury Plain, with 83. We derived density–yield responses for each species and then estimated regional population size under regional food production strategies, including land sharing and land sparing, a range of intermediate strategies, and a novel mixed strategy. In both regions, more species achieved maximum regional population size under land sparing than land sharing. In The Fens, the majority of birds were loser species (estimated to have smaller populations under all food production strategies than in the preagricultural baseline scenario), whereas in Salisbury Plain the majority were winners (smaller populations in the preagricultural baseline scenario). Loser species overwhelmingly achieved maximum regional population size under land sparing, whereas winner species achieved maximum regional population size under either land sharing or an intermediate strategy, highlighting the importance of defining which groups of species are the target of conservation. A novel 3-compartment strategy (combining high-yield farming, natural habitat, and low-yield farming) often performed better than either land sharing or land sparing. Our results support intermediate or 3-compartment land-sparing strategies to maximize bird populations across lowland agricultural landscapes. To deliver conservation outcomes, any shift toward land sparing must, however, ensure yield increases are sustainable in the long term, do not entail increased negative effects on surrounding areas, and are linked to allocation of land for nature.  相似文献   

18.
Determining which vegetation types organisms perceive similarly and classifying these types into groups that function as similar habitats are necessary steps toward expanding the focus of conservation strategies from single species to ecosystems. Therefore, the methods used to determine these habitat classifications are crucial to the successful design and implementation of these conservation strategies. Typically, this process has been accomplished through best professional judgement. We used quantitative techniques to group vegetation types into habitats based on the occurrence of breeding wildlife species ( n = 420) in Oregon. After calculating faunal similarities among all regional vegetation types ( n = 130), we used cluster analysis to group vegetation types into wildlife habitats. We classified the original 130 vegetation types into 30 wildlife habitat types that we believe function similarly. We tested this classification to assess whether vegetation types could be correctly classified into habitat types based on wildlife species composition. Discriminant analysis correctly classified 95% of the vegetation types into their wildlife habitat types, strengthening our confidence in this approach. This approach for classifying habitat types allows consistent development of conservation strategies at coarse resolutions and aids in identifying vegetation types where additional biodiversity surveys are needed. Finally, this approach can be refined continuously as the precision of vegetation mapping and our understanding of organism-habitat associations improve.  相似文献   

19.
Ecosystem function and resilience are compromised when habitats become fragmented due to land‐use change. This has led to national and international conservation strategies aimed at restoring habitat extent and improving functional connectivity (i.e., maintaining dispersal processes). However, biodiversity responses to landscape‐scale habitat creation and the relative importance of spatial and temporal scales are poorly understood, and there is disagreement over which conservation strategies should be prioritized. We used 160 years of historic post‐agricultural woodland creation as a natural experiment to evaluate biodiversity responses to habitat creation in a landscape context. Birds were surveyed in 101 secondary, broadleaf woodlands aged 10–160 years with ≥80% canopy cover and in landscapes with 0‐17% broadleaf woodland cover within 3000 m. We used piecewise structural equation modeling to examine the direct and indirect relationships between bird abundance and diversity, ecological continuity, patch characteristics, and landscape structure and quantified the relative conservation value of local and landscape scales for bird communities. Ecological continuity indirectly affected overall bird abundance and species richness through its effects on stand structure, but had a weaker influence (effect size near 0) on the abundance and diversity of species most closely associated with woodland habitats. This was probably because woodlands were rapidly colonized by woodland generalists in ≤10 years (minimum patch age) but were on average too young (median 50 years) to be colonized by woodland specialists. Local patch characteristics were relatively more important than landscape characteristics for bird communities. Based on our results, biodiversity responses to habitat creation depended on local‐ and landscape‐scale factors that interacted across time and space. We suggest that there is a need for further studies that focus on habitat creation in a landscape context and that knowledge gained from studies of habitat fragmentation and loss should be used to inform habitat creation with caution because the outcomes are not necessarily reciprocal.  相似文献   

20.
Machair is a highly specialised and complex sand dune habitat confined globally to the west coasts of Ireland and Scotland. Irish machair is designated as a priority habitat under the EU Habitats Directive, with the habitat coverage restricted to the machair grassland. The main goals of the study were to describe the Acari fauna inhabiting the Irish machair and to determine the uniqueness of its mite communities in the context of habitat protection. Ten Irish machair sites were selected and samples were taken from the machair grassland and from two types of dunes within the wider machair system: shifting dunes (foredunes) occurring at the beach and stable (fixed) dunes located in the transition zone to the inland grassland flat areas. One hundred and eleven mite taxa were recovered. The most widespread was Scutovertex cf arenocolus Pfingstl et al. 2009, a halophilous species that has been found in the epilittoral zone of Baltic and European Atlantic coasts. The genus Autogneta Hull 1916 (Oribatida: Oppiidae) and the oribatid species Hermaniella granulata (Nicolet 1855) were recorded for the first time for Ireland. Peloptulus cf gibbus Mihelčič 1957, may also be a new record. Multivariate analysis showed that community composition varied between the areas sampled in the machair systems and that in the machair grassland, an Annex I priority habitat in Ireland, was especially different from both dune types sampled. The assemblages also varied significantly between the different sites sampled in the study.  相似文献   

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