实验草原群落研究表明，植物生产力可以通过物种异步性达到稳定，一些物种生物量的减少可以因其它种类的增加而得到补偿。然而，这些发现是否符合自然生态系统则仍是未知数，特别是那些物种多样性受到人为活动引起的全球变化威胁的系统。

由明尼苏达大学生态、进化和行为学系教授 Yann Hautier 带领研究小组分析了五大洲41个大草原多样性–稳定性关系，调查慢性施肥这一全局性物种丢失首要祸首对该类关系的影响。物种丰富的未经处理群落的物种异步性更大，具有更稳定的生物质生产，从而验证了自然草原群落和生物多样性实验的结论一致。然而，施肥削弱了多样性对稳定性的正面作用。与预期相反，其原因并不是由于富营养化后物种减少，而是因为多样化群落的生产率暂时增加以及物种异步性减少。研究结果表明多样性与富营养化对稳定性的独立和协同作用，强调需要了解全球变化因素对自然生态系统服务功能的影响。（编译：中国科学院成都生物研究所 王芋华，王海燕）

Eutrophication weakens stabilizing effects of diversity in natural grasslands.

Abstract  Studies of experimental grassland communities have demonstrated that plant diversity can stabilize productivity through species asynchrony, in which decreases in the biomass of some species are compensated for by increases in others. However, it remains unknown whether these findings are relevant to natural ecosystems, especially those for which species diversity is threatened by anthropogenic global change. Here we analyse diversity–stability relationships from 41 grasslands on five continents and examine how these relationships are affected by chronic fertilization, one of the strongest drivers of species loss globally. Unmanipulated communities with more species had greater species asynchrony, resulting in more stable biomass production, generalizing a result from biodiversity experiments to real-world grasslands. However, fertilization weakened the positive effect of diversity on stability. Contrary to expectations, this was not due to species loss after eutrophication but rather to an increase in the temporal variation of productivity in combination with a decrease in species asynchrony in diverse communities. Our results demonstrate separate and synergistic effects of diversity and eutrophication on stability, emphasizing the need to understand how drivers of global change interactively affect the reliable provisioning of ecosystem services in real-world systems.

原文链接：http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13014.html