Pike Nathan, Tully Thomas, Haccou Patsy, Ferrière Régis
Laboratoire d'Ecologie, Ecole Normale Supérieure, 46 rue d'Ulm, Paris 75005, France.
Proc Biol Sci. 2004 Oct 22;271(1553):2143-8. doi: 10.1098/rspb.2004.2834.
Despite its significance regarding the conservation and management of biological resources, the body of theory predicting that the correlation between successive environmental states can profoundly influence extinction has not been empirically validated. Identical clonal populations from a model experimental system based on the collembolan Folsomia candida were used in the present study to investigate the effect of environmental autocorrelation on time to extinction. Environmental variation was imposed by variable implementation (present/absent) of a culling procedure according to treatments that represented six patterns of environmental autocorrelation. The average number of culling events was held constant across treatments but, as environmental autocorrelation increased, longer runs of both favourable and unfavourable culling tended to occur. While no difference was found among the survival functions for the various treatments, the time taken for 50% of the component populations to become extinct decreased significantly with increasing environmental autocorrelation. Similarly, analysis of all extinct populations demonstrated that time to extinction was shortened as environmental autocorrelation increased. However, this acceleration of extinction can be fully offset if sequential introduction is used in place of simultaneous introduction when founding the populations.
尽管其对于生物资源的保护和管理具有重要意义，但预测连续环境状态之间的相关性会深刻影响灭绝的理论体系尚未得到实证验证。在本研究中，使用了基于弹尾虫白符跳（Folsomia candida）的模型实验系统中的相同克隆种群，以研究环境自相关性对灭绝时间的影响。根据代表六种环境自相关模式的处理方法，通过可变实施（存在/不存在）淘汰程序来施加环境变化。各处理间的平均淘汰事件数保持恒定，但随着环境自相关性的增加，有利和不利淘汰的持续时间往往会变长。虽然在各种处理的生存函数之间未发现差异，但随着环境自相关性的增加，50%的组成种群灭绝所需的时间显著减少。同样，对所有灭绝种群的分析表明，随着环境自相关性的增加，灭绝时间缩短。然而，如果在建立种群时使用顺序引入而非同时引入，则可以完全抵消这种灭绝加速的情况。
