12月21日，英国Nature Communications杂志发表了中科院南京地理与湖泊所王建军、沈吉等的论文《富营养化程度改变温度与生物多样性之间的关联：来自大空间尺度生态学实验的证据》。“我们首次证明微生物同样具有沿着温度梯度分布的生物区系，与经典的动植物生物区系分布相一致。”王建军表示。

生物一般具有一定的分布区，从而形成一定地域或生态位下所特有的物种。比如动植物可分为热带、亚热带等，微生物的分区是否同理可得呢？有观点认为微生物无处不在，动植物分布规律并不适用。王建军课题组选取亚热带（中国）和亚寒带（挪威）两个地区的细菌为研究对象，采用沿海拔梯度添加营养盐的实验方法，探讨了营养盐和温度对水体细菌分布和多样性的影响。

“我们发现，沿着温度梯度或者山地垂直气候带，细菌群落呈现规律性演替，表现为低纬度高海拔地区的群落与高纬度的更相似，或者高纬度低海拔地区的群落与低纬度的更为相似。”王建军说。对此，他打了个比方，中国青藏高原是低纬度高海拔地区，天气寒冷，植被以草地为主，和高纬度、同样寒冷的北欧北回归线北部地区的植被很接近，事实上，细菌群落和植物分布的规律是一致的。

除了上述对微生物生物区系的认识外，王建军课题组还发现，中国研究区域的细菌多样性是挪威区域的2倍左右；向湖泊中输入营养盐，将会降低水体中的微生物多样性，不管是在温度较高的中国，还是温度较低的挪威。“在极端富营养化条件下，温度对细菌物种多样性的影响最强，而在中等温度条件下，富营养化对细菌物种多样性的影响最强。”王建军指出。（来源：科技日报 唐婷）

Nutrient enrichment modifies temperature-biodiversity relationships in large-scale field experiments

Abstract  Climate effects and human impacts, that is, nutrient enrichment, simultaneously drive spatial biodiversity patterns. However, there is little consensus about their independent effects on biodiversity. Here we manipulate nutrient enrichment in aquatic microcosms in subtropical and subarctic regions (China and Norway, respectively) to show clear segregation of bacterial species along temperature gradients, and decreasing alpha and gamma diversity toward higher nutrients. The temperature dependence of species richness is greatest at extreme nutrient levels, whereas the nutrient dependence of species richness is strongest at intermediate temperatures. For species turnover rates, temperature effects are strongest at intermediate and two extreme ends of nutrient gradients in subtropical and subarctic regions, respectively. Species turnover rates caused by nutrients do not increase toward higher temperatures. These findings illustrate direct effects of temperature and nutrients on biodiversity, and indirect effects via primary productivity, thus providing insights into how nutrient enrichment could alter biodiversity under future climate scenarios.

原文链接：http://www.nature.com/articles/ncomms13960