Determining the drivers underlying ecological succession is essential for predicting ecosystem functioning in response to human-induced environmental changes. Although various studies have examined the impacts of nitrogen (N) addition on plant and microbial community diversity, structure and activities, it remains unknown how long-term anthropogenic fertilization affects the ecological succession of microbial functional guilds and its underlying community assembly mechanisms. Here, using archived soils, we examined more than a century's succession in soil microbial functional communities (from 1870 to 2008) from the Park Grass Experiment at Rothamsted Experimental Station, the longest running ecological experiment in the world. Long-term fertilization was found to significantly alter soil functional community structure and led to increasingly convergent succession of soil microbial communities. The importance of stochastic assembly varied greatly in regulating the succession of different microbial guilds. Fertilization had large to medium effects on reducing ecological stochasticity for microbial guilds involved in carbon (C) fixation and degradation, nitrogen (N) fixation and mineralization, and denitrification. This century long-term study elucidated the differing influences of assembly mechanisms on soil microbial functional communities involved in C and N cycling, which has have important implications for understanding and predicting the microbial mediated ecological consequences of human-induced environmental changes.

确定潜在的生态演替驱动因素对于预测生态系统功能以响应人类引起的环境变化至关重要。尽管各种研究已经研究了氮的添加对植物和微生物群落多样性，结构和活性的影响，但仍不清楚长期的人为施肥如何影响微生物功能协会的生态演替及其潜在的群落装配机制。在这里，我们使用存档的土壤，通过Rothamsted实验站的Park Grass实验（世界上运行时间最长的生态实验）研究了一个多世纪以来（1870年至2008年）土壤微生物功能群落的演替。发现长期施肥会显着改变土壤功能性群落结构，并导致土壤微生物群落的趋同收敛。随机装配的重要性在调节不同微生物协会的继承方面有很大的不同。施肥对降低参与碳（C）固定和降解，氮（N）固定和矿化以及反硝化作用的微生物行会的生态随机性具有大到中等的影响。本世纪的长期研究阐明了组装机制对参与碳和氮循环的土壤微生物功能群落的不同影响，这对于理解和预测微生物介导的人为环境变化的生态后果具有重要意义。