Ruokolainen Lasse, Fowler Mike S
Department of Ecology and Evolutionary Biology, Faculty of Biological and Environmental Sciences, Helsinki University, PO Box 65, Viikinkaari 1, 00014 Helsinki, Finland.
Proc Biol Sci. 2008 Aug 7;275(1644):1775-83. doi: 10.1098/rspb.2008.0193.
Understanding community responses to environmental variation is a fundamental aspect of ecological research, with direct ecological, conservation and economic implications. Here, we examined the role of the magnitude, correlation and autocorrelation structures of environmental variation on species' extinction risk (ER), and the probability of actual extinction events in model competitive communities. Both ER and probability increased with increasing positive autocorrelation when species responded independently to the environment, yet both decreased with a strong correlation between species-specific responses. These results are framed in terms of the synchrony between--and magnitude of variation within--species population sizes and are explained in terms of differences in noise amplification under different conditions. The simulation results are robust to changes in the strength of interspecific density dependence, and whether noise affects density-independent or density-dependent population processes. Similar patterns arose under different ranges of noise severity when these different model assumptions were examined. We compared our results with those from an analytically derived solution, which failed to capture many features of the simulation results.
了解群落对环境变化的响应是生态学研究的一个基本方面，具有直接的生态、保护和经济意义。在此，我们研究了环境变化的幅度、相关性和自相关结构对物种灭绝风险（ER）以及模型竞争群落中实际灭绝事件概率的作用。当物种独立响应环境时，ER和概率都随着正自相关性的增加而增加，但随着物种特异性响应之间的强相关性而降低。这些结果是根据物种种群大小之间的同步性以及种群大小变化的幅度来阐述的，并根据不同条件下噪声放大的差异来解释。模拟结果对于种间密度依赖性强度的变化以及噪声是否影响密度独立或密度依赖的种群过程具有稳健性。当检验这些不同的模型假设时，在不同的噪声严重程度范围内也出现了类似的模式。我们将我们的结果与通过解析推导得出的解的结果进行了比较，后者未能捕捉到模拟结果的许多特征。
