Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, Croix du Sud 4, L7-07-04, 1348 Louvain-la-Neuve, Belgium.
Proc Biol Sci. 2020 Jan 29;287(1919):20192818. doi: 10.1098/rspb.2019.2818.
Habitat fragmentation is expected to reduce dispersal movements among patches as a result of increased inter-patch distances. Furthermore, since habitat fragmentation is expected to raise the costs of moving among patches in the landscape, it should hamper the ability or tendency of organisms to perform informed dispersal decisions. Here, we used microcosms of the ciliate to test experimentally whether habitat fragmentation, manipulated through the length of corridors connecting patches differing in temperature, affects habitat choice. We showed that a twofold increase of inter-patch distance can as expected hamper the ability of organisms to choose their habitat at immigration. Interestingly, it also increased their habitat choice at emigration, suggesting that organisms become choosier in their decision to either stay or leave their patch when obtaining information about neighbouring patches gets harder. This study points out that habitat fragmentation might affect not only dispersal rate but also the level of non-randomness of dispersal, with emigration and immigration decisions differently affected. These consequences of fragmentation might considerably modify ecological and evolutionary dynamics of populations facing environmental changes.
生境破碎化预计会增加斑块间的距离，从而减少扩散运动。此外，由于生境破碎化预计会增加在景观中斑块间移动的成本，它应该会阻碍生物进行明智的扩散决策的能力或倾向。在这里，我们使用纤毛虫的微宇宙来通过连接温度不同的斑块的走廊的长度来进行实验性地操纵，以测试生境破碎化是否会影响栖息地选择。我们表明，斑块间距离的两倍增加预计会阻碍生物在移民时选择栖息地的能力。有趣的是，它还增加了它们在移民时的栖息地选择，这表明当获得有关相邻斑块的信息变得更加困难时，生物在决定是留在还是离开其斑块时会更加挑剔。这项研究指出，生境破碎化不仅可能影响扩散率，而且还可能影响扩散的非随机性水平，移民和移民决策受到不同的影响。这些破碎化的后果可能会极大地改变面临环境变化的种群的生态和进化动态。
