Area prioritization for biodiversity conservation in Québec on the basis of species distributions: a preliminary analysis

Results are presented which prioritize areas for potential protection in Québec on the basis of biodiversity considerations. These results are relevant to the ongoing public discussion in Québec about designating new parks and refuges so that the province may fulfil its obligations to Canada's Endangered Spaces Campaign. The prioritization algorithm used in this analysis is based on rarity and complementarity. It attempts to sample biodiversity in as area-efficient a way as possible. The biodiversity surrogates used here comprise a subset of 743 species for which data on spatial distributions are publicly available; the analysis begins with 394 species at risk. It is shown that: (i) the existing network of protected areas in Québec does a poor job of protecting these biodiversity surrogates; (ii) adding adjacent areas to this network will not be the optimal way of protecting these biodiversity surrogates; (iii) many of the areas that have highest priority are in southern Québec, which has a high human population density; (iv) because of (iii), designating parks may not be economically or sociologically feasible and more adaptive alternative conservation plans will have to be devised; (v) coastal areas, riparian habitats, and other wetlands should have high priority for protection but are currently very inadequately represented in the reserve network; (vi) there is some reason for concern about the clear-cut logging of boreal forests in northern Québec; and (vii) the islands, Île d'Anticosti and the Îles-de-la-Madeleine, emerge as being of very significant conservation value and plans for the protection of areas on them should be an immediate goal for biodiversity conservation in Québec.     

Complementarity as a biodiversity indicator strategy

Richness, rarity, endemism and complementarity of indicator taxon species are often used to select conservation areas, which are then assumed to represent most regional biodiversity. Assessments of the degree to which these indicator conservation areas coincide across different taxa have been conducted on a variety of vertebrate, invertebrate and plant groups at a national scale in Britain, Canada, USA and South Africa and at a regional scale in Cameroon, Uganda and the USA. A low degree of spatial overlap among and within these selected indicator conservation areas has been demonstrated. These results tend to suggest that indicator conservation areas display little congruence across different taxa. However, some of these studies demonstrate that many conservation areas for indicator taxa capture a high proportion of non-target species. Thus it appears that indicator conservation areas might sample overall biodiversity efficiently. These indicator conservation areas may, however, exclude species essential for effective conservation, e.g. rare, endemic or endangered species. The present study investigated the value of indicator taxa as biodiversity surrogates using spatial congruence and representativeness of different indicator priority conservation areas. The conservation status of species excluded by the indicator approaches is also assessed. Indicator priority conservation areas demonstrate high land area requirements in order to fully represent non-target species. These results suggest that efficient priority area selection techniques must reach a compromise between maximizing non-target species gains and minimizing land-use requirements. Reserve selection procedures using indicator-based complementarity appear to be approaches which best satisfy this trade-off.     

Two roles for ecological surrogacy: Indicator surrogates and management surrogates

Ecological surrogacy – here defined as using a process or element (e.g., species, ecosystem, or abiotic factor) to represent another aspect of an ecological system – is a widely used concept, but many applications of the surrogate concept have been controversial. We argue that some of this controversy reflects differences among users with different goals, a distinction that can be crystalized by recognizing two basic types of surrogate. First, many ecologists and natural resource managers measure “indicator surrogates” to provide information about ecological systems. Second, and often overlooked, are “management surrogates” (e.g., umbrella species) that are primarily used to facilitate achieving management goals, especially broad goals such as “maintain biodiversity” or “increase ecosystem resilience.” We propose that distinguishing these two overarching roles for surrogacy may facilitate better communication about project goals. This is critical when evaluating the usefulness of different surrogates, especially where a potential surrogate might be useful in one role but not another. Our classification for ecological surrogacy applies to species, ecosystems, ecological processes, abiotic factors, and genetics, and thus can provide coherence across a broad range of uses.     

Biodiversity hotspots are not congruent with conservation areas in the Gulf of California

As marine systems are threatened by increasing human impacts, mechanisms to maintain biodiversity and ecosystem functions and services are needed. Protecting areas of conservation importance may serve as a proxy for maintaining these functions, while also facilitating efficient use and management of limited resources. Biodiversity hotspots have been used as surrogates for spatial conservation importance; however, as many protected areas have been established opportunistically and under differing criteria, it is unclear how well they actually protect hotspots. We evaluated how well the current protected area network and priority areas selected through previous systematic conservation planning exercises preserve biodiversity hotspots in the Gulf of California, Mexico. We also determined spatial congruence between biodiversity hotspots based on different criteria, which may determine their ability to be used as surrogates for each other. We focus on the Gulf of California because it is a megadiverse system where limited information regarding species diversity and distribution has constrained development of strategies for conservation and management. We developed a species occurrence database and identified biodiversity hotspots using four different criteria: species richness, rarity, endemism, and threatened species. We interpolated species occurrence, while accounting for heterogeneous sampling efforts. We then assessed overlap of hotspots with existing protected areas and priority areas, and between hotspots derived by distinct criteria. We gathered 286,533 occurrence records belonging to 12,105 unique species, including 6388 species identified as rare, 642 as endemic, and 386 as threatened. We found that biodiversity hotspots showed little spatial overlap with areas currently under protection and previously identified priority areas. Our results highlight the importance of distinct spatial areas of biodiversity and suggest that different ecological mechanisms sustain different aspects of diversity and multiple criteria should be used when defining conservation areas.     

Operationalizing biodiversity for conservation planning

Biodiversity has acquired such a general meaning that people now find it difficult to pin down a precise sense for planning and policy-making aimed at biodiversity conservation. Because biodiversity is rooted in place, the task of conserving biodiversity should target places for conservation action; and because all places contain biodiversity, but not all places can be targeted for action, places have to be prioritized. What is needed for this is a measure of the extent to which biodiversity varies from place to place. We do not need a precise measure of biodiversity to prioritize places. Relative estimates of similarity or difference can be derived using partial measures, or what have come to be called biodiversity surrogates. Biodiversity surrogates are supposed to stand in for general biodiversity in planning applications. We distinguish between true surrogates, those that might truly stand in for general biodiversity, and estimator surrogates, which have true surrogates as their target variable. For example, species richness has traditionally been the estimator surrogate for the true surrogate, species diversity. But species richness does not capture the differences in composition between places; the essence of biodiversity. Another measure, called complementarity, explicitly captures the differences between places as we iterate the process of place prioritization, starting with an initial place. The relative concept of biodiversity built into the definition of complementarity has the level of precision needed to undertake conservation planning.     

Assessing the mechanisms behind successful surrogates for biodiversity in conservation planning

Limited by the availability of data, conservation planners must use surrogates for biodiversity when selecting conservation areas. Although several methods have been proposed for selecting surrogates, no clear set of species attributes have been described that allow for the efficient a priori selection of surrogate groups. We used a database of 1449 species in two regions of the United States to (1) examine the consistency in the performance of simple taxonomic-based surrogates of biodiversity and (2) test five hypotheses proposed to explain surrogate performance. First, we compared the ability of sites selected to protect members of seven surrogate groups to protect non-surrogate species in the north-western United States and in the Middle-Atlantic region of the eastern United States. Then, in a separate analysis, we tested whether surrogate performance could be explained by (1) taxonomic diversity; (2) nested species distributions; (3) hotspots of biodiversity; (4) species range sizes; (5) environmental diversity. Our first analysis revealed little consistency in the performance of surrogates in the two different study regions. For example, butterflies provided protection for 76% of all other species in the north-western United States but only 56% of all other species in the eastern United States. Our second analysis revealed only weak associations between species characteristics and surrogate performance. Furthermore, these associations proved inadequate for selecting successful surrogates across study regions. Overall, our results suggest that in lieu of searching for optimal surrogate groups, research efforts will be better spent by developing alternative methods for assessing conservation value in areas where data on species distributions are limited.     

Exclusion of agricultural lands in spatial conservation prioritization strategies: consequences for biodiversity and ecosystem service representation

Agroecosystems have traditionally been considered incompatible with biological conservation goals, and often been excluded from spatial conservation prioritization strategies. The consequences for the representativeness of identified priority areas have been little explored. Here, we evaluate these for biodiversity and carbon storage representation when agricultural land areas are excluded from a spatial prioritization strategy for South America. Comparing different prioritization approaches, we also assess how the spatial overlap of priority areas changes. The exclusion of agricultural lands was detrimental to biodiversity representation, indicating that priority areas for agricultural production overlap with areas of relatively high occurrence of species. By contrast, exclusion of agricultural lands benefits representation of carbon storage within priority areas, as lands of high value for agriculture and carbon storage overlap little. When agricultural lands were included and equally weighted with biodiversity and carbon storage, a balanced representation resulted. Our findings suggest that with appropriate management, South American agroecosystems can significantly contribute to biodiversity conservation.     

Endemic vertebrates are the most effective surrogates for identifying conservation priorities among Brazilian ecoregions

Many studies have tested the performance of terrestrial vertebrates as surrogates for overall species diversity, because these are commonly used in priority‐setting conservation appraisals. Using a database of 3663 vertebrate species in 38 Brazilian ecoregions, we evaluated the effectiveness of various subsets for representing diversity of the entire vertebrate assemblage. Because ecoregions are established incorporating information on biotic assemblages, they are potentially more amenable to regional comparison than are national or state lists. We used 10 potential indicator groups (all species; all mammals, birds, reptiles, or amphibians; all endemic species; and endemic species within each class) to find priority sets of ecoregions that best represent the entire terrestrial vertebrate fauna. This is the first time such tests are employed to assess the effectiveness of indicator groups at the ecoregion level in Brazil. We show that patterns of species richness are highly correlated among mammals, birds, amphibians, and reptiles. Furthermore, we demonstrate that ecoregion sets selected according to endemic species richness captured more vertebrate species per unit area than sets based on overall vertebrate richness itself, or than those selected at random. Ecoregion sets based on endemic bird, endemic reptile, or endemic amphibian richness also performed well, capturing more species overall than random sets, or than those selected based on species richness of one or all vertebrate classes within ecoregions. Our results highlight the importance of evaluating biodiversity concordance and the use of indicator groups as well as aggregate species richness. We conclude that priority sets based on indicator groups provide a basis for a first assessment of priorities for conservation at an infracontinental scale. Areas with high endemism have long been highlighted for conservation of species. Our findings provide evidence that endemism is not only a worthwhile conservation goal, but also an effective surrogate for the conservation of all terrestrial vertebrates in Brazil.     

Large expansion of oil industry in the Ecuadorian Amazon: biodiversity vulnerability and conservation alternatives

Ecuador will experience a significant expansion of the oil industry in its Amazonian region, one of the most biodiverse areas of the world. In view of the changes that are about to come, we explore the conflicts between oil extraction interests and biodiversity protection and apply systematic conservation planning to identify priority areas that should be protected in different oil exploitation scenarios. First, we quantified the current extent of oil blocks and protected zones and their overlap with two biodiversity indicators: 25 ecosystems and 745 species (whose distributions were estimated via species distribution models). With the new scheme of oil exploitation, oil blocks cover 68% (68,196 km²) of the Ecuadorian Amazon; half of it occupied by new blocks open for bids in the southern Amazon. This region is especially vulnerable to biodiversity losses, because peaks of species diversity, 19 ecosystems, and a third of its protected zones coincide spatially with oil blocks. Under these circumstances, we used Marxan software to identify priority areas for conservation outside oil blocks, but their coverage was insufficient to completely represent biodiversity. Instead, priority areas that include southern oil blocks provide a higher representation of biodiversity indicators. Therefore, preserving the southern Amazon becomes essential to improve the protection of Amazonian biodiversity in Ecuador, and avoiding oil exploitation in these areas (33% of the extent of southern oil blocks) should be considered a conservation alternative. Also, it is highly recommended to improve current oil exploitation technology to reduce environmental impacts in the region, especially within five oil blocks that we identified as most valuable for the conservation of biodiversity. The application of these and other recommendations depends heavily on the Ecuadorian government, which needs to find a better balance between the use of the Amazon resources and biodiversity conservation.     

Effectiveness of Biodiversity Surrogates for Conservation Planning: Different Measures of Effectiveness Generate a Kaleidoscope of Variation

Conservation planners represent many aspects of biodiversity by using surrogates with spatial distributions readily observed or quantified, but tests of their effectiveness have produced varied and conflicting results. We identified four factors likely to have a strong influence on the apparent effectiveness of surrogates: (1) the choice of surrogate; (2) differences among study regions, which might be large and unquantified (3) the test method, that is, how effectiveness is quantified, and (4) the test features that the surrogates are intended to represent. Analysis of an unusually rich dataset enabled us, for the first time, to disentangle these factors and to compare their individual and interacting influences. Using two data-rich regions, we estimated effectiveness using five alternative methods: two forms of incidental representation, two forms of species accumulation index and irreplaceability correlation, to assess the performance of ‘forest ecosystems’ and ‘environmental units’ as surrogates for six groups of threatened species—the test features—mammals, birds, reptiles, frogs, plants and all of these combined. Four methods tested the effectiveness of the surrogates by selecting areas for conservation of the surrogates then estimating how effective those areas were at representing test features. One method measured the spatial match between conservation priorities for surrogates and test features. For methods that selected conservation areas, we measured effectiveness using two analytical approaches: (1) when representation targets for the surrogates were achieved (incidental representation), or (2) progressively as areas were selected (species accumulation index). We estimated the spatial correlation of conservation priorities using an index known as summed irreplaceability. In general, the effectiveness of surrogates for our taxa (mostly threatened species) was low, although environmental units tended to be more effective than forest ecosystems. The surrogates were most effective for plants and mammals and least effective for frogs and reptiles. The five testing methods differed in their rankings of effectiveness of the two surrogates in relation to different groups of test features. There were differences between study areas in terms of the effectiveness of surrogates for different test feature groups. Overall, the effectiveness of the surrogates was sensitive to all four factors. This indicates the need for caution in generalizing surrogacy tests.     

From fronds to fish: the use of indicators for ecological monitoring in marine benthic ecosystems,with case studies from temperate Western Australia

Ecological indicators are used for monitoring in marine habitats the world over. With the advent of Ecosystem Based Fisheries Management (EBFM), the need for cost effective indicators of environmental impacts and ecosystem condition has intensified. Here, we review the development, utilisation and analysis of indicators for monitoring in marine benthic habitats, and outline important advances made in recent years. We use the unique, speciose benthic system of Western Australia (WA) as a detailed case study, as the development of indicators for EBFM in this region is presently ongoing, and major environmental drivers (e.g. climate change) and fishing practices are currently influencing WA marine systems. As such, the work is biased towards, but not restricted to, indicators that may be important tools for EBFM, such as biodiversity surrogates and indicators of fishing pressure. The review aimed to: (1) provide a concise, up-to-date account of the use of ecological indicators in marine systems; (2) discuss the current, and potential, applications of indicators for ecological monitoring in WA; and (3) highlight priority areas for research and pressing knowledge gaps. We examined indicators derived from benthic primary producers, benthic invertebrates and fish to achieve these goals.     

Time-series effective habitat area (EHA) modeling using cost-benefit raster based technique

For successful characterization of ecological processes and prioritization of habitat networks it is necessary to describe and quantify landscape structure and connectivity. However, at landscape scale, it is highly impractical to measure and map all elements of biodiversity, and therefore, biodiversity surrogates are commonly used to represent biodiversity values. Land cover and vegetation are most often used as a biodiversity surrogate. The study investigated how land use change affects the status of the biodiversity surrogates in terms of the loss or gain of habitat (areal extent), loss of habitat condition (degradation) and habitat fragmentation. Effective habitat area (EHA) and raster based cost–benefit analysis (CBA) modeling techniques were used for the assessment of the impact of land use change scenarios on wildlife habitat as biodiversity surrogates. The modeling was carried out on time-series land cover data from 1972 to 2009 for the Liverpool Range of New South Wales (NSW). The model estimated the future condition of vegetation in each and every grid-cell in the region as a function of current condition, existing land cover, and the threatening processes. The results indicated a continuous pattern of clearing in the region, while the habitat conditions were mostly static throughout the study period. There was a decline in EHA after 1993, by 3%. Clearing was identified as the main cause of such decline during the change period.     

Integrating biodiversity priorities with conflicting socio-economic values in the Guinean–Congolian forest region

Identifying important areas for conserving biodiversity has attracted much discussion, but relatively few studies have dealt with conflicting socio-economic interests in a manner that is fully accountable. For the Guinean–Congolian forest region, we applied quantitative methods to select a network of coarse-scale areas sufficient to represent all forest mammal and bird species at least once. In a separate exercise, we prioritised 50% of the region to represent the same species as many times as possible. In both cases, we sought to minimise potential conflicts between conservation and other socio-economic imperatives by considering benefit-to-cost ratios. We found that by choosing areas to reduce conflicts, we were able to increase markedly the proportion of selected areas with low or medium conflict and decrease the proportion with high conflict. Nonetheless, we cannot expect that conservation goals will always be met unless some of these conflicts are faced and resolved. By working together with specialists from both the biological and socio-economic fields, we show that easily implemented quantitative tools could be useful for supporting the process of finding important areas for biodiversity conservation, while avoiding much of the conflict with other interests.     

Incorporating evolutionary processes into conservation planning using species distribution data: a case study with the western Mediterranean herpetofauna

Aim To incorporate evolutionary processes into conservation planning using species distribution patterns and environmental gradients as surrogates for genetic diversity. Location Western Mediterranean Basin. Methods Distributions of 154 herpetological species were predicted using maximum entropy models, and groups of significantly co‐occurring species (biotic elements) were identified. Environmental gradients were characterized for the complete area and for the area covered by each biotic element, by performing a principal component analysis on the data matrix composed of nine environmental variables. The first two principal component analysis axes were classified into four categories each, and those categories were combined with each other resulting in an environmental classification with 16 categories. To identify priority conservation areas, biotic elements and environmental categories were used as surrogates for the neutral and adaptive components of genetic diversity, respectively. Priority areas for conservation were identified under three scenarios: (1) setting targets for species only; (2) setting targets for species and for each environmental category of the overall area; and (3) setting targets for each species and for each environmental category within each biotic element. Results Nine biotic elements were identified – four for the amphibians and five for the reptiles. Priority areas identified in the three scenarios were similar in terms of amount of area selected, but exhibited low spatial agreement. Main conclusions Prioritization exercises that integrate surrogates for evolutionary processes can deliver spatial priorities that are fairly different to those where only species representation is considered. While new methods are emerging to incorporate molecular data in conservation prioritization, it is unlikely to be enough data for enough taxa for this to be feasible in many regions. We develop an approach using surrogates for both the neutral and adaptive components of genetic diversity that may enhance biodiversity persistence and representation when molecular data are not available or geographically comprehensive.     

Towards a Conceptual Framework for Restoration Ecology

Heightening human impacts on the Earth result in widespread losses of production and conservation values and make large-scale ecosystem restoration increasingly urgent. Tackling this problem requires the development of general guiding principles for restoration so that we can move away from the ad hoc, site- and situation-specific approach that now prevails. A continuum of restoration efforts can be recognized, ranging from restoration of localized highly degraded sites to restoration of entire landscapes for production and/or conservation reasons. We emphasize the importance of developing restoration methodologies that are applicable at the landscape scale. Key processes in restoration include identifying and dealing with the processes leading to degradation in the first place, determining realistic goals and measures of success, developing methods for implementing the goals and incorporating them into land-management and planning strategies, and monitoring the restoration and assessing its success. Few of these procedures are currently incorporated in many restoration projects. The concept that many ecosystems are likely to exist in alternative stable states, depending on their history, is relevant to the setting of restoration goals. A range of measures, such as those being developed to measure ecosystem health, could be used to develop “scorecards” for restoration efforts. Generalizable guidelines for restoration on individual sites could be based on the concepts of designed disturbance, controlled colonization, and controlled species performance. Fewer explicit guidelines are available at the landscape scale, beyond nonquantitative generalities about size and connectivity. Development of these guidelines is an important priority so that urgent large-scale restoration can be planned and implemented effectively.     

Promise and problems in applying quantitative complementary areas for representing the diversity of some Neotropical plants (families Dichapetalaceae, Lecythidaceae, Garyocaraceae, Ghrysobalanaceae and Proteaceae)

Priority areas for in situ conservation are an unavoidable consequence of competition with other land uses, although they are certainly not to be seen as the only areas of value for conservation. In 1990 an international workshop was convened in Manaus, Brazil, to identify priority areas within Amazonia by committee (Workshop-90). A substantial part of the data for this assessment came from five plant families recorded for the Flora Neotropica. We compare the success of the Workshop-90 method in representing these plant species with the results of using a simple quantitative method for seeking complementary areas. The promises of quantitative methods are twofold. First, they force people to make their values explicit, which is important because priorities are dependent on the values and goals of individuals and are not universal. Second, quantitative methods can achieve representation of more of what is valued. For example, within the 90 top-priority areas (an arbitrary but convenient figure taken from Workshop-90), species representation is shown to be increased when using the complementary areas method by 83%. Simple computer implementations of this method can provide the means for fast inter-active exploration of flexibility in the many alternative area choices. This permits monitoring and review with minimum effort as new data on species and threats are acquired. On the other hand, the problem for all methods is the need for very large numbers of data, whether based on species or on any other surrogates for biodiversity, if well-informed decisions are to be made. This is not a particular problem of quantitative methods, but their explicit nature does highlight the shortcomings of data. For example, patterns in the Flora Neotropica data show effects from small samples even though these data are among the best available for any large tropical wet-forest region. Furthermore, in order to assess the longer-term consequences of area choices, quantitative methods will require many explicit local data on factors affecting viability, threat and cost.     

Nature conservation at the edge

Currently, there is an increasing need for evidence-based strategies in nature conservation, for example when designing and establishing nature reserves. In this contribution, we critically assess the ecological relevance of recent nature conservation practices in Kenya (East Africa), a region of global biodiversity hotspots. More specifically, we overlay the distribution of species richness (here based on mammals, birds, amphibians and vascular plants) with the location of nature reserves, the Kenyan agro-ecological zones (areas representing diverging agricultural potentials), and with the spatial distribution of human population density. Our analyses indicate that the majority of protected areas are located in areas with comparatively low species richness, while areas with extraordinary high levels of species richness are not adequately covered by nature reserves. Areas of high agricultural productivity (and with high human demographic pressure) are mainly reserved for high-yield agriculture; however, these regions are also characterised by high species richness. The majority of nature reserves are restricted to the semi-arid regions of Kenya, marginal for agricultural usage, but also with low levels of species richness. Based on this analysis, we prioritize areas for future protection. This single-country case illustrates that agricultural production in high-yield areas outweighs nature conservation goals, even in global biodiversity hotspot regions, and that priority setting may conflict with effective nature conservation.     

Conserving Biogeography: Habitat Loss and Vicariant Patterns in Endemic Squamates of the Cerrado Hotspot

Little is known about the threat levels and impacts of habitat loss over the Cerrado Squamate fauna. The region is under severe habitat loss due to mechanized agriculture, accelerated by changes in the Brazilian National Forest Code. The Squamate fauna of the Cerrado is rich in endemics and is intrinsically associated with its surrounding microhabitats, which make up a mosaic of phitophysiognomies throughout the region. Herein we evaluate current conservation status of Squamate biogeographic patterns in the Brazilian Cerrado, the single savanna among global biodiversity hotspots. To do so, we first updated point locality data on 49 endemic Squamates pertaining to seven non-random clusters of species ranges in the Cerrado. Each cluster was assumed to be representative of different biogeographic regions, holding its own set of species, herein mapped according to their extent of occurrence (EOO). We then contrasted these data in four different scenarios, according to the presence or absence of habitat loss and the presence or absence of the current protected area (PA) cover. We searched for non-random patterns of habitat loss and PA coverage among these biogeographic regions throughout the Cerrado. Finally, with the species EOO as biodiversity layers, we used Zonation to discuss contemporary PA distribution, as well as to highlight current priority areas for conservation within the Cerrado. We ran Zonation under all four conservation scenarios mentioned above. We observed that habitat loss and PA coverage significantly differed between biogeographic regions. The southernmost biogeographic region is the least protected and the most impacted, with priority areas highly scattered in small, disjunct fragments. The northernmost biogeographic region (Tocantins-Serra Geral) is the most protected and least impacted, showing extensive priority areas in all Zonation scenarios. Therefore, current and past deforestation trends are severely threatening biogeographic patterns in the Cerrado. Moreover, PA distribution is spatially biased, and does not represent biogeographic divisions of the Cerrado. Consequently, we show that biogeographic patterns and processes are being erased at an accelerated pace, reinforcing the urgent need to create new reserves and to avoid the loss of the last remaining fragments of once continuous biogeographic regions. These actions are fundamental and urgent for conserving biogeographic and evolutionary information in this highly imperiled savanna hotspot.     

安徽石台县与青阳县苔藓植物多样性

生物多样性保护优先区域代表了生物多样性富集区、典型生态系统与关键物种分布区, 对于生物多样性保护具有重要意义, 但优先区域内自然保护地覆盖率通常较低, 存在很大的保护空缺。苔藓植物作为生物多样性的一个重要组成部分, 在生态系统中发挥着重要作用, 但由于个体细小、分类鉴定困难等, 使得其多样性保护成为整个生物多样性保护中较为薄弱的一环。为了了解我国生物多样性保护优先区域苔藓植物多样性及受保护情况, 本文以黄山-怀玉山生物多样性保护优先区域内的石台县和青阳县为例, 通过系统的样线法调查优先区域内自然保护地内、外的苔藓植物多样性, 比较了其物种组成特点及相似性。结果表明, 该区域共有苔藓植物64科140属344种, 包括苔类植物27科40属106种、藓类植物37科100属238种, 其中有5种为濒危物种。自然保护地内有60科120属270种, 保护地外有46科90属185种, 保护地内、外苔藓植物科、属、种的Jaccard相似性系数分别为0.66、0.50和0.32, 表明自然保护地内、外物种组成差异很大。与石台县和青阳县苔藓植物历史数据相比, 本研究新增苔藓植物14科64属273种, 其中包括安徽省新记录2科9属96种, 而且有18种仅分布于自然保护地外。根据对该区域物种累积曲线及外推估计分析, 当采集足够充分时, 基于标本数的物种多样性预测值为485种, 基于样线数的预测值为563种, 说明石台县和青阳县的苔藓植物多样性仍存在被低估的可能。本研究结果一方面表明了自然保护地之外的苔藓植物在保护中有重要价值, 另一方面也反映了苔藓植物的野外就地保护存在空缺。建议在我国其他生物多样性保护优先区域开展类似的调查和研究, 以期为今后对苔藓植物的分布规律及保护研究提供翔实的基础数据。     

The principle of complementarity in the design of reserve networks to conserve biodiversity: A preliminary history

Explicit, quantitative procedures for identifying biodiversity priority areas are replacing the often ad hoc procedures used in the past to design networks of reserves to conserve biodiversity. This change facilitates more informed choices by policy makers, and thereby makes possible greater satisfaction of conservation goals with increased efficiency. A key feature of these procedures is the use of the principle of complementarity, which ensures that areas chosen for inclusion in a reserve network complement those already selected. This paper sketches the historical development of the principle of complementarity and its applications in practical policy decisions. In the first section a brief account is given of the circumstances out of which concerns for more explicit systematic methods for the assessment of the conservation value of different areas arose. The second section details the emergence of the principle of complementarity in four independent contexts. The third section consists of case studies of the use of the principle of complementarity to make practical policy decisions in Australasia, Africa, and America. In the last section, an assessment is made of the extent to which the principle of complementarity transformed the practice of conservation biology by introducing new standards of rigor and explicitness.