杂食性和模块性结构对食物网多样性和功能的影响

Food webs characterize the energy channels between species, which provides the basis for energy and nutrient flows in ecosystems. However, a comprehensive understanding on the patterns of food web structure and its role in the maintenance of species diversity and ecosystem functioning is largely lacking. Recently, ecologists have accumulated a large amount of food web data and developed theoretical models, which offer new opportunities for understanding the structure and functioning of food webs. This project will focus on two important aspects of food web structure, namely omnivory and modularity. We will first compile a database of all available food web data across the globe, and use this database to reveal the empirical patterns of omnivory and modularity and their biotic and abiotic drivers. Moreover, we will use dynamical food web models to investigate the effects of omnivory and modularity on biodiversity and functioning in food webs and disentangle the underlying mechanisms. By combining data and theory, this project will greatly advance our understanding on the patterns, causes and consequences of omnivory and modularity in food webs. The results of this project will contribute to reconciling the structure, diversity and functioning of food webs and predicting the responses of multitrophic ecosystems to global changes.

食物网刻画了物种间的能量传递路径，是生态系统物质循环和能量流动的基础。然而，关于自然界中食物网的结构特征、及其对物种多样性维持和生态系统功能的作用，仍缺乏系统认识。近年来，生态学家积累了大量的食物网数据，并发展了多个理论模型，为深入理解食物网的结构和功能提供了基础。本项目以食物网的两个重要结构——杂食性和模块性——为研究对象，通过构建全球水平的食物网数据库，分析杂食性和模块性结构的经验格局及其生物和非生物影响因素，并利用近期提出的食物网动态模型研究杂食性和模块性对食物网的物种多样性和功能的影响及作用机制。本项目将结合数据与理论研究，揭示杂食性和模块性的经验格局、影响因素及其生态意义，所得结果有助于促进食物网结构、多样性与功能研究的整合，为预测全球变化下生态系统结构和功能的响应提供理论依据。

食物网刻画了物种间的捕食关系，是生态系统物质循环和能量流动的基础。然而，关于自然界食物网的结构特征、及其对物种多样性维持和生态系统功能的作用，仍缺乏系统认识。杂食性和模块性是食物网结构复杂性的两个重要特征，对食物网多样性和生产力具有重要影响。本研究结合食物网数据和理论模型，分析杂食性和模块性结构的经验格局及其影响因素，并探究杂食性和模块性对食物网的物种多样性和功能的影响及作用机制。主要发现有： (1) 揭示了自然界食物网中普遍存在杂食性和模块性结构；(2) 发展了新的捕食模型并发现水生和陆生食物网的捕食结构存在显著差异；(3) 阐明了杂食性结构和网络复杂性对生态系统多样性和生产力的促进作用；(4) 提出了异质生境中食物网多样性的新预测模型；(5) 解析了物种化学计量生态位对食物网多样性和种群动态的影响。共发表SCI论文13篇、中文论文1篇，包括Ecology, Ecology Letters, PNAS等期刊。总体来说，项目成果为理解食物网结构的形成和生态功能提供了新认识。