Graham Laura J, Haines-Young Roy H, Field Richard
1Geography and Environment, University of Southampton, Southampton, SO17 1BJ UK.
2School of Geography, Sir Clive Granger Building, University of Nottingham, Nottingham, NG7 2RD UK.
Landsc Ecol. 2017;32(5):989-1003. doi: 10.1007/s10980-017-0504-0. Epub 2017 Mar 25.
Increasing human populations in urban areas pose a threat to species' persistence through habitat loss and fragmentation. It is therefore essential that we develop methods to investigate critical habitat loss thresholds and least detrimental landscape configurations.
We develop a framework to assess how the pattern of habitat loss impacts the ecological and social characteristics of a landscape and how this varies depending on the species and criteria by which it is judged.
We use a scenario-based approach to test six propositions in which habitat is lost preferentially based on patch characteristics. We use eight bird and two amphibian species as indicator species. To compare scenarios, we present a method combining the output from a metapopulation model with measures of social impacts of land-cover change in a multiple criteria decision analysis. We also determine whether a habitat loss threshold exists, below which small loss of habitat can lead to large loss of species' occupancy.
We found that, of the scenarios presented, preferentially losing common habitats and smaller patches was least detrimental for both ecological and social factors. Threshold effects were found for all but the generalist bird species.
We have outlined a workflow which allows for transparent, repeatable comparison between landscapes. This workflow can be used to compare urban landscape plans, or to develop general understanding of the impacts of different forms of habitat loss. Reassuringly, the recommendations based on the scenarios presented are in keeping with received conservation wisdom: to prioritise larger and/or rarer patches.
城市地区不断增长的人口通过栖息地丧失和破碎化对物种的存续构成威胁。因此，我们必须开发方法来研究关键栖息地丧失阈值和危害最小的景观配置。
我们开发了一个框架，以评估栖息地丧失模式如何影响景观的生态和社会特征，以及这种影响如何因被评估的物种和标准而异。
我们采用基于情景的方法来测试六个命题，其中栖息地根据斑块特征优先丧失。我们将八种鸟类和两种两栖类物种用作指示物种。为了比较不同情景，我们提出了一种方法，将集合种群模型的输出与多标准决策分析中土地覆盖变化的社会影响度量相结合。我们还确定是否存在栖息地丧失阈值，低于该阈值，栖息地的少量丧失可能导致物种占有率的大幅下降。
我们发现，在所呈现的情景中，优先丧失常见栖息地和较小斑块对生态和社会因素的危害最小。除广适性鸟类外，所有物种均发现了阈值效应。
我们概述了一种工作流程，可实现景观之间透明、可重复的比较。此工作流程可用于比较城市景观规划，或用于增进对不同形式栖息地丧失影响的总体理解。令人欣慰的是，基于所呈现情景的建议与公认的保护理念一致：优先考虑较大和/或较稀有的斑块。
