Collaborative Research: The role of network topology and environmental filtering in shaping the ecology of spatially structured communities

合作研究：网络拓扑和环境过滤在塑造空间结构社区生态中的作用

• 批准号: 1202932
• 负责人: Bryan Brown
• 金额: $ 16.82万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1202932&HistoricalAwards=false
• 关键词: Collaborative; Research; role; network; topology

Why are species found in certain combinations and not others? Why are some species not found in habitats that seem suitable for their needs? A fundamental goal of ecology is to understand the processes that drive patterns in species occurrence. An organism's "local" environment can exert influence on where it occurs, e.g., climate, competition for resources, and disturbance. However, "regional" factors - such as the ability of organisms to colonize available habitat - are also important. This project addresses two fundamental questions: 1) What is the relative importance of local versus regional factors in controlling species composition? 2) How does that relative importance shift with elements of landscapes, and the ability of organisms to move across those landscapes? The project will address these two questions using communities of aquatic invertebrates in river networks. These organisms include the larval forms of many insects, such as mayflies and caddisflies, and animals like snails and crayfish. These communities are ideal for addressing the questions because rivers have a very distinct, branching configuration. Furthermore, rivers endure intense human degradation, and aquatic invertebrates are often used as indicators of water quality. The project takes advantage of stream restoration activity, which almost always includes large-scale habitat modification: the ultimate manipulation of "local" factors. Three types of approaches will be employed to address the research questions: surveys of restoration sites, experimental manipulations of local factors - specifically stream-bottom habitat features - in river systems, and experiments using artificial streams to control for both local and regional processes. The project will have important implications for applied ecology because stream assessment often involves characterizations of aquatic communities under the assumption that local habitat alone determines their composition. Stream restoration efforts (estimated at $1 billion annually in the U.S.) are often evaluated based on such bioassessment techniques. Previous findings suggest that this assumption may apply only to specific portions of a stream network. This research will be the first to begin to explore spatial dependence of habitat factors in detail, not only advancing the field of ecology, but providing information about the importance of river network position in developing expectations for restoration.

为什么在某些组合而不是其他组合中找到物种？为什么在栖息地中找不到一些适合其需求的物种？生态学的一个基本目标是了解推动物种发生模式的过程。 生物体的“本地”环境可以对其发生的位置产生影响，例如气候，资源竞争和干扰。 但是，“区域性”因素（例如生物体定居可用栖息地的能力）也很重要。该项目解决了两个基本问题：1）局部因素与区域因素控制物种组成的相对重要性是什么？ 2）相对重要性如何随景观的要素以及生物体在这些景观中移动的能力的转变？ 该项目将使用河网络中的水生无脊椎动物群落来解决这两个问题。 这些生物包括许多昆虫的幼体形式，例如五氟和caddisflies，以及蜗牛和小龙虾等动物。 这些社区是解决问题的理想选择，因为河流具有非常独特的分支配置。 此外，河流忍受了强烈的人类降解，水生无脊椎动物通常被用作水质的指标。 该项目利用了流恢复活动，几乎总是包括大规模的栖息地修改：对“局部”因素的最终操纵。 将采用三种类型的方法来解决研究问题：对恢复地点的调查，对局部因素的实验操作 - 特别是河底栖息地特征 - 在河流系统中，以及使用人工溪流来控制本地和区域过程的实验。 该项目将对应用生态学具有重要意义，因为流评估通常涉及水生群落的特征，假设仅当地栖息地决定了它们的组成。经常根据这种生物评估技术评估流恢复工作（估计在美国每年10亿美元）。 先前的发现表明，此假设可能仅适用于流网络的特定部分。 这项研究将是第一个开始详细探讨栖息地因素的空间依赖的人，不仅可以推进生态学领域，而且提供有关河网络地位在发展恢复期望的重要性的信息。