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1.
How can conservation planners optimally and effectively allocate limited resources between imminently threatened and presently secure areas? Such choices must be made at multiple spatial scales involving a variety of conservation targets. Allocation strategies range from a “fire-fighting” approach, which gives priority to heavily developed areas at high risk of further habitat loss, to a “pre-emptive” approach giving priority to intact habitat tracts before they become threatened. We determined optimal dynamic reserve selection strategies when selections are made in imminently threatened and presently secure areas that will become threatened at uncertain times in the future. The objective was to maximize the expected number of endemic species conserved, predicted with species-area curves. The model was solved for three forms of species-area curve proposed in theoretical studies of habitat loss. Alternative scenarios were considered on the relationship between land prices and development risk. For the most commonly proposed form of the species-area relationship, the fire-fighting approach is optimal even if land prices rise substantially when presently secure areas become threatened. This reflects the assumption that species decline accelerates only after a large proportion of original habitat has been lost. The possibility of large species losses at lower levels of habitat loss justifies at least some pre-emptive conservation, even if land prices are not correlated with threat. If species decline is proportional with habitat loss, the optimal conservation strategy depends strongly on land price dynamics.  相似文献   

2.
Prioritizing new areas for conservation in the Rocky Mountains of North America is important because the current intensity and scale of human development poses an immediate threat to biodiversity. We identified priority areas for avian biodiversity within a 3200-km corridor from Yellowstone National Park in Wyoming, US to the Yukon in Canada (the Y2Y region). We applied the conservation planning tool, MARXAN, to summarize 21 avian values. MARXAN minimizes the area delineated, while simultaneously incorporating multiple criteria (species richness representation, spatial clustering) and biodiversity targets into a single mappable solution. We prioritized avian biodiversity ‘hotspots’ at continental and ecoprovincial scales based on: (1) avian species richness; and (2) habitat associations of 20 focal species. At the continental scale, the single best solution represented 19% of the Y2Y region; 29% of this solution overlapped with existing protected areas. In northern Y2Y, large contiguous areas with high avian value were concentrated on the western edge of the continental divide. In southern Y2Y, contiguous areas were smaller and more numerous than in the north. In contrast to the majority of studies prioritizing conservation areas, we explored the effect of varying the extent of the target region by analyzing data at the scale of the entire Y2Y region and for eight ecoprovinces separately. We found that (1) large contiguous patches characterized only three ecoprovinces, while for the remaining ecoprovinces, numerous single scattered habitat patches of varying sizes were required to meet conservation goals; and (2) generally, only a small percentage of sites was already protected within the existing protected areas network. Our results are important for conservation planners and resource managers in the Y2Y region for incorporating areas of high conservation value for birds at regional and ecoprovincial scales during conservation project design and adaptive planning.  相似文献   

3.
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   

4.
There is an obvious need to incorporate biodiversity concerns into the policies and practices of sectors that operate outside protected areas, especially given the widespread devolution of power to local (municipal) authorities regarding land-use decision-making. Consequently, it is essential that we develop systematic (target-driven) conservation planning products that are both user-friendly and user-useful for local government officials, their consultants and the elected decision makers. Here, we describe a systematic conservation planning assessment for South Africa’s Subtropical Thicket Biome that considered implementation opportunities and constraints from the outset by developing - with stakeholders - products (maps and guidelines) that could be readily used for local government land-use planning. The assessment, with concomitant stakeholder input, developed (i) Megaconservancy Networks, which are large-scale conservation corridors of multiple ownership that achieve targets principally for biodiversity processes; (ii) conservation status categories (critically endangered, endangered, vulnerable, currently not vulnerable) for all biodiversity features, identified on the basis of available extant habitat to achieve conservation targets, and (iii) a conservation priority map which integrates (i) and (ii). This map was further interpreted for municipal-level decision-makers by way of corresponding guidelines for land-use in each of the conservation status categories. To improve general awareness of the value of biodiversity and its services, a handbook was compiled, which also introduced new and impending environmental legislation. Within 18 months of the production of these products, evidence of the effective integration, or mainstreaming, of the map and its guidelines into land-use planning has been encouraging. However, more effort on increasing awareness of the value of biodiversity and its services among many stakeholder groups is still required. Nonetheless, our approach of planning for implementation by considering the needs and obligations of end users has already yielded positive outcomes. We conclude by providing suggestions for further improving our approach.  相似文献   

5.
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   

6.
Decisions on biodiversity management and conservation are increasingly based on indicators. These imply, explicitly or implicitly, a number of criteria such as nativeness, rarity, endangeredness and (economic) value. We investigated to which degree such criteria matter to members of the general public and conducted a survey in eight sites across Europe (n = 2378). We explored the relationships between perceived desirability of a species’ population increase and six species-related attributes, including previous population change, rarity, vulnerability, harmfulness, value, attractiveness, and nativeness.For all three species types investigated, previous population change, followed by perceived harmfulness and value, had the strongest relationship with desirability of future increase. Perceived nativeness played only a minor role in informing a species’ desirability. A strong relationship between previous change and desirability of future increase could also be found in a number of additional species and six different habitat types, suggesting that previous change is a key criterion that the general public draws on to inform their attitudes towards biodiversity management.We compare the roles of such criteria for the general public to those used in the scientific and political discourse, and draw conclusions for the use of indicators in the conservation debate, arguing that biodiversity management that is strongly focused on nativeness might fall short of the interests of the citizenship, whereas other criteria, such as population trends, harmfulness and role and value of a species in the ecosystem strongly resonate with the views of the general public.  相似文献   

7.
Computational methods for marine reserve design are frequently used as decision-support tools for the identification of conservation areas. Most reserve-selection algorithms minimise the cost of the reserve system whilst aiming to meet specified biodiversity objectives. Here, we extend a widely-used selection algorithm, Marxan, to incorporate several important considerations related to biodiversity processes and management. First we relax the scorched earth assumption to allow conservation features in non-reserve zones to contribute explicitly to conservation objectives. To achieve this, we generate conservation targets at landscape scales rather than focusing purely on the representation of features within reserves. Second, we develop the notion of spatial dependencies further to incorporate spatial heterogeneity in the value of individual conservation features such as habitat types. We use the example of ontogenetic migrations of fish from mangroves to coral reefs because it nicely demonstrates how spatial ecological processes generate predictable heterogeneity in habitat value that should be considered in the reserve design process. Lastly, we show how habitat value can be disaggregated into ecosystem processes and services. Using a case study for the Belize Barrier Reef we compare reserve networks generated using our new approach with the results of traditional analyses. Consideration of the contribution of different protection zones, connectivity among habitats and more complex management goals resulted in up to a 52% increase in the mean biomass of commercially and ecologically-important fish species represented in the landscape. Our approach strengthens the ecological basis of reserve-design algorithms and might facilitate the uptake of ecosystem-based management into reserve design.  相似文献   

8.
Knowledge about the ecology of urban water systems is very scarce. We assessed the conservation value of urban drainage systems in lowland areas and compared these with similar watercourses in rural areas. A total of 36 water bodies in urban areas were selected to investigate the macroinvertebrate biodiversity in relation to environmental variables. Multivariate analysis of aquatic macroinvertebrate assemblages was used to distinguish urban water types and to link these types to key environmental variables. Several biodiversity indices for urban water systems were compared with those for other drainage systems in The Netherlands. Four types of macroinvertebrate assemblages were distinguished in the urban water systems, differing in environmental conditions and values of ecological indicators. The variation in macroinvertebrate assemblages was significantly explained by nitrate, pH, grain size (sediment composition), transparency, nymphaeid and submerged vegetation. Urban drainage systems can sustain a macroinvertebrate biodiversity comparable to that of drainage systems in rural areas (ditches and canals) and (semi)natural watercourses (lotic waters such as small streams and rivulets) and can even be a habitat for red list species. To optimize biodiversity values, urban water management should aim at lowering nutrient levels, stimulating vegetation (diversity of habitat structure) and increasing transparency, which are key factors for macroinvertebrate diversity. We show the potential conservation benefits of water systems in urban areas, but further studies are needed to investigate the optimal design of cities to include biodiversity as an integrated part of the urban environment, thereby sustaining a higher biodiversity in an increasingly urbanizing world.  相似文献   

9.
Recent attempts to streamline the identification of areas requiring immediate conservation attention have resulted in the development of prioritisation procedures that identify areas of biodiversity importance facing large threats in the near future. This study incorporated biodiversity data on bird and vegetation distribution with an assessment of land use suitability for cultivation and afforestation for the Limpopo Province of South Africa. The low altitude savanna regions in the northeast contain high species diversity, but are unsuitable to alternative forms of land use and are well conserved (by e.g., the Kruger National Park). The central and eastern mountain ranges, sites of high biodiversity, are suitable to dryland cultivation and afforestation and are thus potential conservation priorities. Areas with high biodiversity values, e.g., irreplaceable areas that contain biodiversity features essential for meeting conservation targets, were then investigated for their potential land-use threats in order to prioritise those needing immediate conservation actions. We suggest how losses of biodiversity could be minimised by reaching such decisions more quickly.  相似文献   

10.
Reserve networks are a major tool of ecological management aiming at biodiversity conservation. Maximizing the number of species conserved with the minimum land sacrifice is a primary requirement in reserve design. In this study, we examine the efficiency of five different scenarios to conserve: (i) the biodiversity of one target group and (ii) the overall biodiversity of an area. The study was conducted in Dadia Reserve, in northern Greece. Six groups of species were selected to represent its biodiversity: woody plants, orchids, Orthoptera, aquatic and terrestrial herpetofauna, and small terrestrial birds. The scenarios examined represent different conservation approaches to select network sites. For each approach, the starting point was one of the above six groups of species, considered as the target group. In scenario A, which reflects the hotspot approach, the sites richest in species are selected. Scenario B selects the sites most complementary in terms of species richness. The next two scenarios use the principle of environmental representativeness, expressed in terms of habitat (scenario C) or vegetation (scenario D). Under scenario E, sites forming the network are selected at random. The rank of scenarios in terms of preserving the species of the target group was always B > A > C > D > E, irrespective of the group considered as target group. Their rank, when preservation of the total biodiversity was the issue, was B, A > C, D > E.  相似文献   

11.
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   

12.
Conservation biologists use the species-area relationship for a variety of purposes, including upscaling diversity from small plots to regions, predicting species loss, and for identifying biodiversity hotspots and prioritizing actions to protect them. Despite its widespread use, several complications that affect the accuracy of its application are often overlooked. First, interpretation of the species-area relationship is a function of the census design used to construct it. Nested census designs guarantee only that one individual each of a given number of species is within the sampled area, but we are almost always concerned with the loss or protection of more than one individual of each species. Census designs using non-contiguous plots are useful for sampling large regions, but their interpretation is not straightforward because species number is a function of the spatial extent of the landscape and the size of the sample units. Second, power function behavior is often assumed, even though the species-area relationship often displays curvilinearity on log-log plots across scale ranges pertinent to conservation. Finally, applications of the species-area relationship often assume that the area of interest is contiguous while in practice it seldom is, and so calculations using the species-area relationship need to account for beta diversity between disjunctive areas.  相似文献   

13.
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   

14.
基于InVEST模型和莫兰指数的甘肃省生境质量与退化度评估   总被引：5，自引：3，他引：2  
生境质量的高低与土地利用/土地覆被类型为生物多样性提供的栖息地适宜性有直接关系,尤其是农业开发活动、城市、道路等严重威胁生境质量,为了评估西北生态脆弱地区生境质量和退化程度,该研究以甘肃省为例,应用INVEST模型和莫兰指数对甘肃省生境质量和生境退化空间特征进行分析,明确其热点区域,并探讨了生境质量与退化度及其热点与各类自然保护地的关系。结果表明：甘肃省生境质量从南到北逐渐下降,而生境退化度从北到南逐渐升高,自然生态条件好的区域这种变化主要取决于人类活动的位置和强度;甘肃省生境质量热点区面积占到全省国土面积的25.59%,高于全省自然保护地面积占比,形成了保护空缺,甘肃省生境退化热点地区面积虽然不高,但多为自然生态条件较好的区域;各类保护地中,国家公园是各类保护地类型中生境退化度最低的类型,保护水平相对较低的其他保护地类型在生境质量和退化程度上表现出相反的结果。研究结果对精准实施生物多样性保护战略和生态系统管理决策具有重要意义。  相似文献   

15.
The status and trends of global biodiversity are often measured with a bias towards datasets limited to terrestrial vertebrates. The first global assessment of an insect order (Odonata) provides new context to the ongoing discussion of current biodiversity loss. A randomly selected sample of 1500 (26.4%) of the 5680 described dragonflies and damselflies was assessed using IUCN’s Red List criteria. Distribution maps for each species were created and species were assigned to habitat types. These data were analysed in respect to threat level for regions and habitat types. We have found that one in 10 species of dragonflies and damselflies is threatened with extinction. This threat level is among the lowest of groups that have been assessed to date, suggesting that previous estimates of extinction risk for insects might be misleading. However, Odonata only comprise a small invertebrate order, with above-average dispersal ability and relatively wide distribution ranges. For conservation science and policy to be truly representative of global biodiversity a representative cross-section of invertebrates needs to be included.  相似文献   

16.
The establishment and maintenance of a system of protected areas is central to regional and global strategies for the conservation of biodiversity. The current global trend towards human population growth and widespread environmental degradation means that such areas are becoming increasingly isolated in fragmented habitat islands. In regions in which this process is well advanced a high proportion of species are thus predicted to have become restricted to protected areas. Here using uniquely detailed datasets for Britain, a region with close to the global level of percentage coverage by statutory protected areas, we determine the extent of restriction of Red List vascular plant species of conservation concern to these areas. On the basis of currently known distributions, overall our results strongly support the importance of a dual conservation strategy in Britain, in which protected areas are maintained with particular reference to those biodiversity features (such as many threatened plant species) that are highly dependent on them, and in which components of the wider landscape are also managed in such a way as to promote the abundance and distribution of such features with particular reference to those which are unlikely to persist in protected areas alone.  相似文献   

17.
Biological reserves are established to protect natural resources and represent the diversity of environments found within a region. Unfortunately, many systems of protected areas do not proportionally capture the range of environmental conditions occupied by species and communities. Combinations of habitat loss and climate change may exacerbate these representational biases, and result in future distributions of environmental conditions that bare little resemblance to historic patterns. New protected areas need to be established to correct existing biases, and create conservation networks that remain representative despite climate change, habitat loss, and changes in species distributions. We demonstrate a new method to identify and prioritize habitat based on its value for improving bioclimatic representation. We assessed representation provided by existing protected areas for 301 Proteaceae species under historic and projected 2050 climate across the Cape Floristic Region in South Africa. The existing reserve system has relatively modest biases with respect to current species distributions and climate. However, if the system is not supplemented, protected areas in 2050 will capture an increasingly skewed sample of climatic conditions occupied by Proteaceae. These biases can be repaired through the systematic establishment of new protected areas, and many of the most valuable areas coincide with high priority ecosystem components and irreplaceable elements identified in the Cape Action for People and the Environmental conservation plan. Protecting these areas achieves nearly the best possible improvement in climatic representation while also meeting biodiversity representation goals.  相似文献   

18.
Payments for environmental services (PES) aim to improve the supply of environmental services by making payments to service providers, which are conditional on the provision of those services. Payments cannot be conditional unless the service can be effectively monitored, making monitoring of service provision a central feature of PES. We introduce a framework for designing monitoring programmes in PES schemes for biodiversity conservation. We suggest that decisions must be made concerning the indicators to be used (e.g. species, threats or positive actions), how they will be monitored (e.g. using ground-based or remote-sensed data) and how the monitoring information will be used to differentiate payments (e.g. trends over time, performance relative to neighbouring sites, performance against a target). We then use this framework to examine the feasibility of monitoring species and threat indicators in a community-based biodiversity payment scheme in Menabe, Madagascar. We find that detecting population changes, differences between sites, or whether a target has been met is only feasible for the most common indicators, suggesting that it may not be possible to base payments on the species conservationists are most interested in. If payments need to be based on relatively common indicators, threat indicators may be more appropriate than common species indicators due to a stronger relationship to the service of interest (presence of a rare species). It is, however, possible to incorporate information from rare indicators using accumulation curves to compare between sites. This study highlights the impact of indicator choice on the monitoring effort required in a biodiversity PES. We urge caution in the design of payment schemes and suggest it can be detrimental to structure a scheme around an indicator that cannot be effectively monitored.  相似文献   

19.
In a perfect world, systematic conservation planning would use complete information on the distribution of biodiversity. However, information on most species is grossly incomplete. Two main types of distribution data are frequently used in conservation planning: observed and predicted distribution data. A fundamental question that planners face is - which kind of data is better under what circumstances? We used simulation procedures to analyse the effects of using different types of distribution data on the performance of reserve selection algorithms in scenarios using different reserve selection problems, amounts of species distribution known, conservation targets and costs. To compare these scenarios we used occurrence data from 25 amphibian and 41 reptile species of the Iberian Peninsula and assumed the available data represented the whole truth. We then sampled fractions of these data and either used them as they were, or converted them to modelled predicted distributions. This enabled us to build three other types of species distribution data sets commonly used in conservation planning: “predicted”, “transformed predicted” and “mixed”. Our results suggest that reserve selection performance is sensitive to the type of species distribution data used and that the most cost-efficient decision depends most on the reserve selection problem and on how much we have of the species distribution data. Choosing the most appropriate type of distribution data should start by evaluating the scenario circumstances. While there is no one best approach for every scenario, we discovered that using a mixed approach usually provides an acceptable compromise between species representation and cost.  相似文献   

20.
Conservation actions frequently need to be scheduled because both funding and implementation capacity are limited. Two approaches to scheduling are possible. Maximizing gain (MaxGain) which attempts to maximize representation with protected areas, or minimizing loss (MinLoss) which attempts to minimize total loss both inside and outside protected areas. Conservation planners also choose between setting priorities based solely on biodiversity pattern and considering surrogates for biodiversity processes such as connectivity. We address both biodiversity processes and habitat loss in a scheduling framework by comparing four different prioritization strategies defined by MaxGain and MinLoss applied to biodiversity patterns and processes to solve the dynamic area selection problem with variable area cost. We compared each strategy by estimating predicted species’ occurrences within a landscape after 20 years of incremental reservation and loss of habitat. By incorporating species-specific responses to fragmentation, we found that you could improve the performance of conservation strategies. MinLoss was the best approach for conserving both biodiversity pattern and process. However, due to the spatial autocorrelation of habitat loss, reserves selected with this approach tended to become more isolated through time; losing up to 40% of occurrences of edge-sensitive species. Additionally, because of the positive correlation between threats and land cost, reserve networks designed with this approach contained smaller and fewer reserves compared with networks designed with a MaxGain approach. We suggest a possible way to account for the negative effect of fragmentation by considering both local and neighbourhood vulnerability to habitat loss.  相似文献   

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