南水北调中线水源地河流大型无脊椎动物多样性对人类干扰的响应

Increasing human disturbances have dramatically altered lotic biodiversity both regionally and globally. However, the knowledge about the patterns, processes and mechanisms linked to human-induced intervention driving the multidimensional loss of biodiversity in streams and rivers remains yet limited, particularly in phylogenetic and functional diversity. Here, we address this issue by choosing five rivers representing different levels of human disturbances, located in the source region of the Middle Route of South-North Water Diversion Project, as one-case study. The aims of this study concentrate mainly on the impacts of anthropogenic activities on three aspects (alpha, beta and gamma) of taxonomic, phylogenetic and functional diversity of macroinvertebrates in these rivers. Firstly, we depict the key patterns of taxonomic, phylogenetic and functional diversity between and within the five rivers, and identify their spatial and temporal differences. Secondly, we detect the key driving extrinsic (both naturally- and human-induced environmental variables) and intrinsic factors (representing by spatial factors), integrate them into one proposed framework, and partition their relative contribution to respective diversity patterns (especially patterns of beta diversity). Finally, we will establish the quantitative relationships between macroinvertebrate diversity and the stress of anthropogenic activities based on above studies, to predict and assess the impact of human interventions on species composition, evolutionary history and functional roles of biodiversity. These stereoscopic and multidimentional scientific probes should remarkably rich the knowledge about lotic macroinvertebrate diversity, enhance understanding of the biodiversity alterations involving community phylogenetic and functional traits, and promote in-depth explorating the association between biodiversity loss and ecosystem multifunction. These results can provide important implications for river restoration, landscape assessment, management and conservation planning in the water source region.

日益加剧的人类干扰已显著改变河流生物多样性。而对生物多样性在不同维度上对人类干扰响应的关键过程和机制的认识仍然十分有限，尤其在系统发育和功能多样性方面。项目拟选择南水北调中线水源地的代表性河流，以大型无脊椎动物为研究对象，开展物种、系统发育和功能多样性各自在α、β和γ三个层次对人类干扰的响应研究。首先，在人类干扰梯度下，描述三种维度的α、β和γ多样性在不同河流和干扰强度下的时空差异及水平。其次，甄别出驱动这些格局变化的关键空间因子和环境因子，解析它们各自/联合的作用力大小、方向和水平。最后，在系统把握关键驱动要素的基础上，构建无脊椎动物多样性对人类干扰响应的预测模型，预测和评估人类干扰对无脊椎动物物种组成、进化历史和功能的影响。本研究尝试整合多样性的三个维度来探索人类干扰对无脊椎动物多样性影响的过程和机制，可为水源地河流生物多样性评价、流域系统管理、修复和保护等提供科学支撑。

日益加剧的人类干扰已显著改变河流生物多样性的各个维度。而对河流生物多样性在不同维度对人类干扰响应的关键过程和机制的认识仍然十分有限，尤其在系统发育和功能多样性方面。项目选择丹江口水源地的代表性河流，以大型无脊椎动物为研究对象，开展其物种、系统发育和功能多样性维度对人类干扰的响应研究。研究结果显示：（1）在不同的干扰样点组间（参照、中度受损、重度受损），无脊椎动物群落的物种组成和功能性状组成均具显著差异，而功能性状对特定人为干扰有更好的响应。其中，生活史特征（如化性、体型）和与抵抗力和恢复力相关的性状（飞行能力、生活型等）可以有效地指示人为干扰。物种组成主要受流域土地利用的影响，性状组成则受河段生境条件影响更大，表明两者反映不同尺度的人为干扰状况。将物种和性状组成相结合，可提高环境评价的准确性。（2）三个维度的 alpha 多样性指数对人为干扰、自然环境、质量效应以及扩散限制的响应不同。系统发育多样性指数只与人为干扰因子高度相关，可有效地应用于研究流域内人为干扰的评估。物种和功能多样性指数由于受到多重过程（包括自然环境和扩散）的强烈作用，在一定程度上会影响评估的准确性。（3）三个维度beta多样性格局的形成机制存在差异。物种和系统发育多样性主要由置换组分构成，功能多样性主要由嵌套组分构成。物种和系统发育beta多样性主要受空间因子的影响，表明扩散限制或历史过程的强烈作用。功能beta多样性主要受到局域环境的影响，表明性状和环境间密切的相关性。空间因子对嵌套结构更为重要，表明扩散限制和历史过程可强烈驱动群落间物种、进化枝和性状的增加或丧失。局域环境对置换组分更加重要，表明环境过滤是造成群落间元件周转和替换的主要原因。本研究从不同的角度探索人类干扰对无脊椎动物多样性影响的过程和机制，可为河流生物多样性评价、流域系统管理、修复和保护等提供科学支撑。