Collaborative Research: Resource ratio effects on stream detritus and detritivores

生态系统的人为养分富集化是一种全球现象，往往对生态群落产生负面影响，导致生物多样性降低。营养素的增加会改变食物资源中碳和磷等营养元素的比例，并会影响生态系统中物种的多样性和类型。许多水生物种已经进化到使用低质量的树叶凋落物作为食物资源(即有害食肉动物)；这些物种适应碳与磷的比例较高的饮食。当食物资源中的磷水平升高时，就像在人类富集型水生生态系统中经常发生的情况一样，一些有害物种的生长可能会受到负面影响，因为从它们体内清除多余磷的能量成本增加。营养素升高对消费者增长产生的这种违反直觉的负面影响可能会导致水生生态系统中更多物种的丧失。该项目将确定碎屑资源中碳/磷比例的变化是否会对Ozark Highland溪流中不同富集度的昆虫物种的生长产生可预测的影响。这项研究将结合实验室实验和对河流生态系统的区域数据集的分析，以确定碎屑资源的人为磷浓缩是否对水生有害生物和其他物种多样性产生直接负面影响。该项目的结果将提供更全面的了解营养物质丰富对河流系统的影响，这些信息有助于改善这些生态系统的管理。通过与分水岭团体和国家机构的接触，这项研究的结果将传达给当地社区和自然资源管理人员。拟议的活动将支持研究生和本科生的研究培训和职业发展，包括任职人数不足群体的成员。这个项目代表了来自一所研究型大学和一所以本科为主的大学的两名初级研究人员的合作。

Anthropogenic nutrient enrichment of ecosystems is a global phenomenon that often negatively affects ecological communities leading to lower biodiversity. Elevated nutrients can alter the proportion of nutritional elements such as carbon and phosphorus in food resources and can influence the diversity and type of species present in ecosystems. Many aquatic species have evolved to use low quality leaf litter as food resources (i.e., detritivores); these species are adapted to a diet that has a high ratio of carbon relative to phosphorus. When phosphorus levels in food resources are elevated, as is often the case in human-enriched aquatic ecosystems, the growth of some detritivore species may be negatively impacted due to an increased energetic cost of eliminating excess phosphorus from their bodies. This counter-intuitive, negative effect of elevated nutrients on consumer growth may lead to the loss of detritivore species from aquatic ecosystems. This project will determine whether changes in the ratio of carbon to phosphorus in detrital resources result in predictable effects on growth of insect detritivore species across an enrichment gradient in Ozark Highland streams. The research will combine laboratory experiments with an analysis of a regional data set on stream ecosystems to determine whether anthropogenic phosphorus enrichment of detrital resources is having direct negative effects on aquatic detritivore species diversity.Results from this project will provide a more thorough understanding of the ways that nutrient enrichment can impact stream systems, information that is useful to improved management of these ecosystems. Through outreach to watershed groups and state agencies, the results of this research will be communicated to the local community and natural resource managers. The proposed activity will support research training and career development of graduate and undergraduate students, including members of under-represented groups. This project represents a collaboration of two beginning investigators from a research university and a primarily undergraduate university.