研究发现群落功能多样性影响土壤侵蚀速率

日前，中国科学院生态环境研究中心城市与区域生态国家重点实验室景观格

局与生态过程研究组博士生朱火星等在导师傅伯杰院士指导下，系统研究了黄土高原半干旱草地群落功能组成对土壤侵蚀的影响。相关成果在线发表于《应用生态学杂志》。

该研究通过群落调查识别了黄土高原地区13个主要物种，使用多模型推断的方法分析了群落功能组成指标对土壤侵蚀的影响。研究发现，功能分异度对土壤侵蚀有很强的负效应，而且这种效应在不同的降雨事件之间表现出很好的稳定性；特定的功能性状也能够减缓土壤侵蚀，但其效能受到降雨强度的影响。

研究表明，群落的功能多样性显著影响土壤侵蚀速率。因此，研究提出了基于植物性状的“筛选—模拟—维护”植被恢复框架，把确立较高群落功能多样性的恢复目标转化为管理人员可以实际操作的具体流程。基于此框架，能够开发出把群落功能多样性作为主要关切的更加完善的恢复方案，以满足当前植被恢复和管理的迫切需求。（来源：中国科学报 陆琦）

Reducing soil erosion by improving community functional diversity in semi-arid grasslands

Abstract Great efforts have been made to control soil erosion by restoring plant communities in degraded ecosystems world-wide. However, soil erosion has not been substantially reduced mainly because current restoration strategies lead to large areas of mono-specific vegetation, which are inefficient in reducing soil erosion because of their simple canopy and root structure. Therefore, an advanced understanding of how community functional composition affects soil erosion processes, as well as an improved restoration scheme to reduce soil erosion, is urgently needed. We investigated the effect of community functional composition on soil erosion in restored semi-arid grasslands on the Loess Plateau of China. Community functional composition of 16 restored grasslands was quantified by community-weighted mean (CWM) and functional diversity (FD) trait values, which were calculated from nine plant functional traits of thirteen locally dominant plant species. Species richness and evenness were also measured. Soil erosion rates were measured using standard erosion plots. The multimodel inference approach was used to estimate the direction and the relative importance of these biodiversity indices in reducing soil erosion. A robust and strong negative effect of functional divergence (FDiv) on soil erosion was found. The prevalence of particular trait combinations can also decrease soil erosion. The greatest control over soil erosion was exerted when the community mean root diameter was small and the root tensile strength was great. Synthesis and applications: These findings imply that community functional diversity plays an important role in reducing soil erosion in semi-arid restored grasslands. This means that current restoration strategies can be greatly improved by incorporating community functional diversity into restoration design. We propose a trait-based restoration framework for reducing soil erosion, termed ‘SSM’ (Screening–Simulating–Maintaining). SSM aims to translate the target of community functional diversity into community assemblages that can be manipulated by practitioners. Based on this framework, a comprehensive procedure, highlighting functional diversity as the primary concern in determining optimal community assemblages, was developed to meet the pressing need for more effective restoration strategies to reduce soil erosion.

原文链接：http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12442/pdf