Negative landscape-scale fragmentation effects are often inferred from negative patch-scale edge effects. I tested this cross-scale extrapolation using two evaluations. First, I searched for studies that estimated the direction of both a patch-scale edge effect and a landscape-scale fragmentation effect. The directions were concordant and discordant in 55% and 45% of cases, respectively. Second, I extracted from the literature a sample of landscape-scale fragmentation effects on individual species. Then, for each species I searched for studies from which I could calculate the slope of its patch-scale edge effect. Species showing negative patch-scale edge effects were nearly equally likely to show negative or positive landscape-scale fragmentation effects, and likewise for species showing positive patch-scale edge effects. The results mean that the efficacy of policies related to habitat fragmentation cannot be inferred from observed patch-scale edge effects. Such policies require landscape-scale evidence, comparing species' responses in landscapes with different levels of fragmentation.

中文翻译：

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斑块规模的边缘效应并不表示景观规模的破碎效应

负的景观尺度破碎效应通常是从负的斑块尺度边缘效应推断出来的。我使用两项评估测试了这种跨尺度外推法。首先，我搜索了估计斑块尺度边缘效应和景观尺度碎片效应方向的研究。分别有 55% 和 45% 的案例方向一致和不一致。其次，我从文献中提取了景观尺度破碎化对单个物种影响的样本。然后，对于每个物种，我搜索了研究，从中我可以计算其斑块尺度边缘效应的斜率。表现出负斑块尺度边缘效应的物种几乎同样可能表现出负或正景观尺度破碎效应，对于表现出正斑块尺度边缘效应的物种也是如此。结果意味着与栖息地破碎化相关的政策的有效性不能从观察到的斑块规模边缘效应推断出来。这些政策需要景观尺度的证据，比较不同破碎程度的景观中物种的反应。