Collaborative Research: Disturbance and the Structure of River Food

本项目研究水流扰动对水生食物链长度的影响。生态学理论指出，干扰会缩短食物链，但初步观察表明，加州北部河流的周期性冬季冲刷实际上可能会延长食物链。通过室内试验确定关键无脊椎动物类群对捕食的敏感性，实地试验评估干扰对物种相互作用强度的影响，人工冲刷对底栖生物和掠食性鱼类摄食率的影响，以及实地调查比较调节（低干扰）和自然（高干扰）河流的营养结构，研究干扰与营养动力学的相互作用。这项研究很重要，原因有几个。首先，这是测试（和修正）关于食物网结构和干扰在群落结构中的作用的基本理论的理想系统。本研究结果对研究泄洪调度和防洪工程对河流生物多样性和群落生态的影响具有重要意义。该研究结果将为河流管理和恢复提供重要信息。＊＊＊

9318003 Power This project investigates the effect of stream disturbance on the length of aquatic food chains. Ecological theory indicates that food chains should be shortened by disturbance, but preliminary observations suggest that periodic winter scouring in northern California rivers may actually lengthen food chains. The interplay of disturbance and trophic dynamics is investigated by laboratory trials to establish susceptibility of key invertebrate taxa to predation, field experiments to assess the effect of disturbance on the strength of species interactions and of artificial scouring on the benthos and feeding rates of predatory fish, and field surveys comparing the trophic structure of regulated (low disturbance) and natural (high-disturbance) rivers. %%% This research is important for several reasons. First, this is an ideal system for testing (and revising) fundamental theories on the stucture of food webs and the role of disturbance in community structure. The results of this study have important implications for the effects of dam- release schedules and flood control projects on the biodiversity and community ecology of rivers. Results from this research will provide important information for stream and river management and restoration. ***