CAREER:Functional diversity and ecosystem function provisioning by a guild of macrofaunal consumers in riverine ecosystems

淡水生态系统拥有令人难以置信的多样性，正在经历比任何其他生态系统类型更快的生物多样性丧失。尽管如此，人们对这些不同的生态群落提供的生态系统服务知之甚少。淡水贻贝是一类高度濒危、物种丰富的长寿动物，在维持水质方面发挥着关键作用，并对淡水生态系统产生强烈影响。虽然淡水贻贝的生态价值得到了广泛的评价，但它们的生活史和在重要营养物质循环中的作用往往被忽视。这些生物体的密度变化很大，可能非常高。贻贝密度和特性的变化使其成为研究动物对河流中限制性营养物质(即氮和磷)循环的影响的理想方法。拟议的研究将把淡水贻贝群落的研究与关键生态系统服务的调查结合起来。研究成果还将被用来将关于生物多样性在生态系统功能中的作用的想法引入到本科课程、K-12日间训练营和课后课程的教学中。该项目将结合生物、群落和生态系统规模的测量，研究物种特征和群落组成在改变河流生态系统中能量和营养物质的通量和储存方面的交互作用。近年来，人们对确定动物在生物地球化学热点中的直接作用产生了极大的兴趣，但它们在微生物介导的营养转化中的间接作用以及这一过程的特定背景依赖性被忽视。这项研究将通过将物种特征、全系统观察和实验操作联系起来，研究淡水贻贝如何影响溪流中的营养物质转化：1)物种特征(如化学计量学、体型)是否影响动物在营养循环中所起的作用，这是否随环境背景而变化？2)动物聚集体是否通过将营养物质从沉积物主动转移到水柱而显著改变营养物质循环和转化？3)物种特征和种群波动是否影响营养物质循环和跨越空间和时间的转化？这项研究将通过调查群落组成和巧合的特征多样性如何在时间和空间上影响生物地球化学循环，同时为高度濒危群体的保护提供信息，从而促进科学理解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Freshwater ecosystems harbor incredible diversity and are experiencing more rapid biodiversity losses than any other ecosystem type. Despite this, little is known of the ecosystem services provided by these diverse ecological communities. Freshwater mussels are a highly imperiled, species-rich group of long-lived animals that play critical roles in maintaining water quality, and strongly impact freshwater ecosystems. While the ecological value of freshwater mussels is widely appreciated, their life history and role in the cycling of important nutrients is often overlooked. The density of these organisms is quite variable and can be very high. Variation in both mussel densities and characteristics make them ideal for studies of the impacts of animals on the cycling of limiting nutrients (i.e., nitrogen and phosphorus) in rivers. The proposed research will integrate the study of communities of freshwater mussels with investigations of critical ecosystem services. Research results will also be used to introduce ideas on the role of biodiversity in ecosystem function into the instruction of undergraduate courses, K-12 day camps, and after school programs.Using a combination of measurements across organismal, community, and ecosystem scales, this project will examine the interactive role of species traits and community composition in altering the fluxes and stores of energy and nutrients in river ecosystems. There has been great interest in recent years in ascertaining the direct roles of animals in creating biogeochemical hotspots, but their indirect role in microbially-mediated nutrient transformations and the trait-specific context-dependency of this has been overlooked. This research will examine how freshwater mussels influence nutrient transformations in streams by linking species traits, system-wide observations, and experimental manipulations to ask: 1) Do species traits (e.g. stoichiometry, body size) influence the role animals play in nutrient cycling and does this vary with environmental context? 2) Do animal aggregations significantly alter nutrient cycling and transformations via the active transfer of nutrients from the sediments to the water column? 3) Do species traits and population fluctuations influence nutrient cycling and transformations across space and time? This research will advance scientific understanding by investigating how community composition and coincidental trait diversity influences biogeochemical cycling over time and space while also informing conservation of a highly imperiled group.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.