Collaborative Research: Food-Chain Length in Streams: Testing the Role of Ecosystem Size, Resource Availability and Disturbance

合作研究：在溪流中的食物链长度测试生态系统大小，资源可用性和干扰的作用。Finlay，Jacques，C.明尼苏达大学-双城社区结构和生态系统功能的一个关键决定因素是食物链长度，能量和物质从食物网的底部转移到顶部的次数的量度。 食物链长度通过改变营养相互作用影响群落结构，影响生态系统功能，并在一定程度上决定了污染物在顶级捕食者（包括许多人类食用的鱼类）中的浓度。 食物链长度也受到人类活动的强烈影响，例如，采伐活动和生境破碎化。 尽管食物链长度在生态学中占有中心地位，但人们对控制这一基本食物网属性的因素知之甚少。 该项目的重点是生态系统的大小，资源的可用性和干扰如何在河流生态系统中发现的食物网中控制食物链的长度。 为了解决这个问题，该项目将比较从北美40多条河流收集的数据，使用现有的数据集以及进行新的实地测量，并应用稳定同位素技术来估计食物链长度。 更深入地了解河流中的食物链长度将有助于阐明正在进行和加速的人类环境变化与重要社会问题（如污染物浓度、生物多样性和碳循环）之间的复杂联系。 该项目将支持三名新教师在其职业生涯的关键早期阶段的合作，培养博士后研究员，一名研究生和几名本科生进行跨学科研究，并在当地高中进行实践K-12推广工作，使用流食物网作为代表生态复杂性的工具，并教授对生物多样性重要性的认识。

Collaborative Research: Food-Chain Length in Streams-Testing the Role of Ecosystem Size, Resource Availability and Disturbance.Finlay, Jacques, C.University of Minnesota - Twin CitiesA critical determinant of community structure and ecosystem function is food-chain length, a measure of the number of times energy and materials are transferred from the bottom to the top of a food web. Food-chain length affects community structure by altering trophic interactions, influences ecosystem functions, and, in part, determines the concentration of contaminants in top predators, including many fish that humans eat. Food-chain length is also strongly affected by human activities through, e.g., harvesting activities and habitat fragmentation. Despite the central place of food-chain length in ecology, relatively little is known about the factors controlling this fundamental food web property. This project focuses on how ecosystem size, resource availability and disturbance govern food-chain length in food webs found in river ecosystems. To address this question, the project will compare data collected from 40+ rivers across North America, using existing data sets as well as making new field measurements and applying stable isotope techniques to estimate food-chain length. A deeper understanding of food-chain length in streams will help elucidate the complex linkages between ongoing and accelerating human environmental changes on important societal concerns such as contaminant concentrations, biodiversity, and carbon cycling. This project will support the collaboration of three new faculty members during the crucial early phase of their careers, train a postdoctoral fellow, one graduate student, and several undergraduates in cross-disciplinary research, and conduct a hands on K-12 outreach effort in local high schools using stream food webs as a tool for representing ecological complexity and for teaching an appreciation of the importance of biodiversity.