Cátedra Rui Nabeiro-Biodiversidade, Universidade de Évora, Casa Cordovil 2ª Andar, Rua Dr Joaquim Henrique da Fonseca, 7000-890 Évora, Portugal.
Ecol Lett. 2011 Nov;14(11):1125-33. doi: 10.1111/j.1461-0248.2011.01681.x. Epub 2011 Sep 28.
Forecasts of species endangerment under climate change usually ignore the processes by which species ranges shift. By analysing the 'climate paths' that range shifts might follow, and two key range-shift processes--dispersal and population persistence--we show that short-term climatic and population characteristics have dramatic effects on range-shift forecasts. By employing this approach with 15 amphibian species in the western USA, we make unexpected predictions. First, inter-decadal variability in climate change can prevent range shifts by causing gaps in climate paths, even in the absence of geographic barriers. Second, the hitherto unappreciated trait of persistence during unfavourable climatic conditions is critical to species range shifts. Third, climatic fluctuations and low persistence could lead to endangerment even if the future potential range size is large. These considerations may render habitat corridors ineffectual for some species, and conservationists may need to consider managed relocation and augmentation of in situ populations.
在预测物种因气候变化而受到威胁时，通常会忽略物种分布范围变化的过程。通过分析分布范围可能遵循的“气候路径”，以及两个关键的分布范围变化过程——扩散和种群持续存在——我们发现短期气候和种群特征对分布范围变化的预测有巨大的影响。我们采用这种方法对美国西部的 15 种两栖动物进行了分析，结果却出人意料。首先，气候变化的年代际变异性会导致气候路径出现空白，从而阻止物种的分布范围发生变化，即使不存在地理障碍也是如此。其次，在不利的气候条件下保持种群持续存在，这一迄今未被重视的特征对物种的分布范围变化至关重要。第三，即使未来的潜在范围很大，气候波动和低持续存在也可能导致物种濒危。这些考虑因素可能会使一些物种的生境走廊失效，保护主义者可能需要考虑对原地种群进行有管理的迁移和扩充。
