Department of Biology, Centre for Conservation Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
Proc Biol Sci. 2012 Jan 7;279(1726):144-52. doi: 10.1098/rspb.2011.0673. Epub 2011 May 25.
Dispersal plays a key role in the response of populations to climate change and habitat fragmentation. Here, we use data from a long-term metapopulation study of a non-migratory bird, the house sparrow (Passer domesticus), to examine the influence of increasing spring temperature and density-dependence on natal dispersal rates and how these relationships depend on spatial variation in habitat quality. The effects of spring temperature and population size on dispersal rate depended on the habitat quality. Dispersal rate increased with temperature and population size on poor-quality islands without farms, where house sparrows were more exposed to temporal fluctuations in weather conditions and food availability. By contrast, dispersal rate was independent of spring temperature and population size on high-quality islands with farms, where house sparrows had access to food and shelter all the year around. This illustrates large spatial heterogeneity within the metapopulation in how population density and environmental fluctuations affect the dispersal process.
扩散在种群对气候变化和生境破碎化的响应中起着关键作用。在这里，我们利用一项对非迁徙鸟类——家麻雀（Passer domesticus）的长期基因库研究的数据，来检验春季温度升高和密度依赖对出生地扩散率的影响，以及这些关系如何取决于生境质量的空间变化。春季温度和种群大小对扩散率的影响取决于生境质量。在没有农场的低质量岛屿上，随着温度的升高和种群数量的增加，扩散率也随之增加，在这些岛屿上，家麻雀更容易受到天气条件和食物可获得性的季节性波动的影响。相比之下，在有农场的高质量岛屿上，扩散率与春季温度和种群大小无关，在这些岛屿上，家麻雀全年都可以获得食物和庇护所。这表明，在基因库中，种群密度和环境波动如何影响扩散过程存在很大的空间异质性。
