BackgroundTaxon- and/or ecosystem-based definitions of management units typically focus on conspicuous species and physical habitat limits; these definitions implicitly assume that these classification systems are related to the mechanisms that determine biodiversity persistence. However, ecological theory shows that this assumption may not be supported. Herein, we introduce the use of modularity analysis for objectively identifying management units and topological roles that land cover type plays on species movement through the landscape.MethodsAs a case study, we used a coastal system in Uruguay, with 28 land cover types and five taxa (from plants to mammals). A modularity-based approach was used to identify subsets of habitats with biotic affinity, termed modules, across the different taxonomic groups. Modularity detects the tendency of some land cover types to have a higher probability of the mutual interchange of individuals than other land cover types. Based on this approach, pairs of habitats that co-occur in the same module across taxa were considered in the same biodiversity management units (BMU). In addition, the topological role of each habitat was determined based on the occurrence of species through the landscape.ResultsOur approach determined three management units that combine land cover types usually considered independent, but instead are interrelated by an occurrence-based ecological network as proxies of the potential flow of individual and land use. For each selected taxon, the specific topological role of each habitat was determined.ConclusionsThis approach provides an objective way of delineating spatial units for conservation assessment. We showed that land cover types within these spatial units could be identified as refuges for specific types of biodiversity, sources of propagules for neighboring or overall landscapes, or stepping-stones connecting sub-regions. The preservation of these topological roles might help maintain the mechanisms that drive biodiversity in the system. Interestingly, the role of land cover type was strongly contingent on the taxa being considered. The method is comprehensible, applicable to policy and decision-makers, and well-connected with ecological theory. Moreover, this approach complements existing methods, introduces novel quantitative uses of available information, determines criteria for land cover classification and identifies management units that are not evident through other approaches.

中文翻译：

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一种基于模块的方法来确定生物多样性管理单位

背景分类和/或基于生态系统的管理单位定义通常侧重于显眼的物种和自然栖息地限制；这些定义隐含地假设这些分类系统与决定生物多样性持久性的机制有关。然而，生态学理论表明，这种假设可能不被支持。在此，我们介绍了模块化分析的使用，以客观地确定土地覆盖类型对景观中物种运动的管理单元和拓扑作用。方法作为案例研究，我们使用了乌拉圭的海岸系统，具有 28 个土地覆盖类型和五个分类群（从植物到哺乳动物）。基于模块化的方法用于识别具有生物亲和力的栖息地子集，称为模块，跨越不同的分类群。模块化检测某些土地覆盖类型具有比其他土地覆盖类型更高的个体相互交换概率的趋势。基于这种方法，在同一生物多样性管理单元 (BMU) 中考虑了在同一模块中跨分类群共同出现的成对栖息地。此外，每个栖息地的拓扑作用是根据物种在景观中的出现来确定的。 结果我们的方法确定了三个管理单元，它们结合了通常被认为是独立的土地覆盖类型，但通过基于发生的生态网络作为代理个人和土地使用的潜在流量。对于每个选定的分类群，确定了每个栖息地的特定拓扑作用。结论该方法提供了一种为保护评估划定空间单位的客观方法。我们表明，这些空间单位内的土地覆盖类型可以确定为特定类型生物多样性的避难所、邻近或整体景观的繁殖源或连接子区域的垫脚石。保留这些拓扑作用可能有助于维持驱动系统生物多样性的机制。有趣的是，土地覆盖类型的作用在很大程度上取决于所考虑的分类群。该方法通俗易懂，适用于政策制定者和决策者，并且与生态理论有很好的联系。此外，这种方法补充了现有方法，引入了可用信息的新定量用途，