How well do Important Bird Areas represent species and minimize conservation conflict in the tropical Andes?

Where high species richness and high human population density coincide, potential exists for conflict between the imperatives of species conservation and human development. We examine the coincidence of at‐risk bird species richness and human population in the countries of the tropical Andes. We then compare the performance of the expert‐driven Important Bird Areas (IBA) scheme against a hypothetical protected‐areas network identified with a systematic reserve selection algorithm seeking to maximize at‐risk bird species representation. Our aim is to assess the degree to which: IBAs contain a higher richness of at‐risk species than would be expected by chance, IBAs contain more people than would be expected by chance, and IBAs are congruent with complementary areas that maximize species representation with an equivalent number of sites. While the correlation of richness and population was low for the region as a whole, representation of all at‐risk bird species required many sites to be located in areas of high human population density. IBA sites contained higher human population densities than expected by chance (P < 0.05) and were markedly less efficient in representing at‐risk bird species of the region than sites selected using the reserve selection algorithm. Moreover, overlap between IBAs and these latter sites was very limited. Expert‐driven selection procedures may better reflect existing sociopolitical forces, including land ownership and management regimes, but are limited in their ability to develop an efficient, integrated network of sites to represent priority species. Reserve selection algorithms may serve this end by optimizing complementarity in species representation among selected sites, whether these sites are adopted independently or as a supplement to the existing reserve network. As tools of site selection, they may be particularly useful in areas such as the tropical Andes where complex patterns of species disjunction and co‐occurrence make the development of representative reserve networks particularly difficult. Furthermore, they facilitate making spatially explicit choices about how reserve sites are located in relation to human populations. We advocate their use not in replacement of approaches such as the IBA initiative but as an additional, complementary tool in ensuring that such reserve networks are developed as efficiently as practically possible.     

系统保护规划的理论、方法及关键问题

为了减缓生物多样性丧失的趋势、将有限的保护资源用于关键区域,Margules等提出了系统保护规划(Systematic Conservation Planning)概念和方法,目前该方法已成为国际主流保护规划方法。与传统基于专家决策的保护体系规划方法不同,系统保护规划拥有量化的保护目标、保护成本,并综合考虑保护体系连通性、人为干扰因素,使用优化算法计算,从而获得空间明晰的生物多样性保护体系。在阐述规划理念、规划流程与方法的基础上,重点评述了生物多样性替代指标的选择、保护规划成本的计算、保护目标的设置、规划结果的可靠性评估等关键问题,并结合我国的具体情况,探讨了该方法在我国的应用前景,以期为推进我国生物多样性与生态服务功能的保护做出贡献。     

系统保护规划和不可代替性分析在区域规划中的应用

在区域规划中应该把保护和发展密切结合起来,才能为实施可持续发展战略奠定基础。遵循系统保护规划和不可代替性分析的观点,内蒙古克 什克腾旗应该建立10个不同类型的保护区,并与有关部门和社区实施共同管理,建设成为一个可持续发展的示范基地。     

基于C-Plan系统保护规划软件的长白山阔叶红松林保护效率

阔叶红松林(Broadleaved Korean pine forest)是北温带物种最丰富的地带性群落之一,是极危动物东北虎(Panthera tigris altaica)的重要栖息地。长白山地区是阔叶红松林在中国范围内的中心分布区,中国政府建立了由24个自然保护区组成的网络来保护阔叶红松林及其他自然生态系统。以长白山地区为研究区域,在系统保护规划方法流程框架下,选择阔叶红松林生态系统中具有代表性的物种和群落做为优先保护对象,并制定量化保护目标,利用系统保护规划软件C-Plan,计算了研究区域规划单元的不可替代性值、各保护对象在保护网络中实现其保护目标的贡献值(Ti)及包含多个保护对象的保护区域的保护效率值(C),以此在多角度评估保护网络及其中各自然保护区的保护效率。结果显示:现有保护网络涵盖了本研究确立保护对象种类的90.4%,已达到保护目标的保护对象占其总数的25.3%。以保护阔叶红松林为\"标尺\"衡量各保护区的保护效率,长白山国家级自然保护区与松花江三湖省级自然保护区保护效率值最高,其余各保护区保护效率值不足10,整个保护网络保护效率值为59.99。不可替代性分析结果显示:仍有79.97%的高保护价值规划单元未被现有保护网络覆盖,空间上存在明显空缺。将空缺纳入保护网络后,新保护网络的保护效率值将提高到96.32,提高了36.33,77种保护对象达到保护目标(占保护对象总数的92.8%),5种保护对象仍未能达到保护目标,但保护对象贡献值Ti均不同程度提高,保护成效显著。     

国家公园优先保护区域识别——以浙江丽水为例

如何充分利用有限的资源更好地保护生物多样性一直都是保护地管理所追求的目标。整合保护对象、优化保护地的空间布局、有效识别国家公园优先保护区域是当前中国国家公园体制建设的主要任务。本研究以浙江丽水为例,采用生态模型评估了该区域关键生态系统服务(固碳释氧、水文调节、水资源、土壤保持)的空间分布格局,同时运用MaxEnt模型模拟了37种濒危物种适宜栖息地分布的空间格局。在此基础上,将关键生态系统服务和濒危物种作为保护对象,通过系统保护规划模型MARXAN,在0.4 km×0.4 km规划网格上计算丽水各规划单元的生态保护不可替代性指数,并结合当地管理需求,综合识别了国家公园优先保护区域。结果表明:2005—2015年间,研究区生态系统固碳量为0.05 kg C·m^-2·a^-1,释氧量为0.13 kg O₂·m^-2·a^-1,水文调节量为83.25亿m³·a^-1,水资源量为803 mm·a^-1,土壤保持量为95.53 t·h...     

Representation of natural vegetation in protected areas: capturing the geographic range

Current conservation strategies for plant and animal species rarely address the need to protect the species throughout its geographic range thereby capturing potential genetic and ecological variation. We examined the degree that existing protected areas in the western United States satisfied this goal for four widespread vegetation cover types. We used latitude and longitude to stratify the distribution of these types into 16 cells, each of which was further stratified by up to five elevation classes. While protection of some vegetation types was high in parts of their range, it was minimal to nonexistent in other parts. While it is yet to be shown that protecting a given species throughout its geographic range is essential for its long-term existence, in the face of often unpredictable environmental changes, it seems a prudent course to follow. Our results suggest that if full range protection is a conservation goal, the existing network of protected areas may be inadequate for the task.     

Shades of irreplaceability: towards a measure of the contribution of sites to a reservation goal

In most regions there are many possible ways of combining numbers of sites into reserve systems that represent a range of natural feasures. The irreplaceability of a site is operationally defined as the percentage of these alternative systems in which it occurs. This is a fundamental measure of the conservation value of the site in terms of its potential contribution to the achievement of a reservation goal or, alternatively, the options for reservation that are lost if the site is lost. The measure allows decisions to be made on the future of individual sites in the context of their value, in combination with other sites, to the conservation of the full range of natural features in a region. It also provides a logical framework for the design of whole systems of reserves, with decisions proceeding from the most to the least irreplaceable. Irreplaceability can be measured directly for small data sets but must be predicted for regional data sets. A promising approach to prediction is discussed that requires validation with more extensive trials. The irreplaceability of a site depends on a specific reservation target and changes as some of the site's features become progressively represented in reserves elsewhere. The concept of irreplaceability undermines notions of conservation value that are static or based on a single static system of sites to achieve a reservation goal.     

Reconciling global mammal prioritization schemes into a strategy

The huge conservation interest that mammals attract and the large datasets that have been collected on them have propelled a diversity of global mammal prioritization schemes, but no comprehensive global mammal conservation strategy. We highlight some of the potential discrepancies between the schemes presented in this theme issue, including: conservation of species or areas, reactive and proactive conservation approaches, conservation knowledge and action, levels of aggregation of indicators of trend and scale issues. We propose that recently collected global mammal data and many of the mammal prioritization schemes now available could be incorporated into a comprehensive global strategy for the conservation of mammals. The task of developing such a strategy should be coordinated by a super-partes, authoritative institution (e.g. the International Union for Conservation of Nature, IUCN). The strategy would facilitate funding agencies, conservation organizations and national institutions to rapidly identify a number of short-term and long-term global conservation priorities, and act complementarily to achieve them.     

Why do we lose protected areas? Factors influencing protected area downgrading,downsizing and degazettement in the tropics and subtropics

Protected areas (PAs) are an essential tool for the conservation of biodiversity globally. Previous studies have focussed on the effectiveness of PAs and the design of optimal PA networks. However, not all PAs remain intact permanently; many PAs undergo downgrading, downsizing and/or degazettement (PADDD), a fact largely ignored until recently. The drivers of enacted PADDD events and the factors influencing its spatial occurrence are poorly understood, potentially undermining the efficacy of PAs and PA networks. Here we examine the spatial relationship between PADDD and economic, demographic and structural variables, using a 110‐year data set of 342 enacted PADDD events across 44 countries in the tropics and subtropics. We find that the probability of an enacted PADDD event increases with the size of the PA and through a synergistic interaction between PA size and local population densities. Our results are robust to the under‐reporting of enacted PADDD events that occur among smaller PAs and in regions with lower population density. We find an economic motive for PADDD events, given that the opportunity costs associated with larger PAs are higher, on average, than smaller PAs. Our findings suggest a need for conservation practitioners to better consider PA characteristics, as well as the social, economic and political context in which PAs are situated, to aid the creation of more efficient and sustainable PA networks. In particular, the dynamics of enacted PADDD events highlight the need to explicitly consider PA robustness as a core component of systematic conservation planning for PA networks.