Riparian nutrients and food webs on a regulated river

受监管河流上的河岸营养物和食物网

• 批准号: 6694971
• 负责人: Teresa M Tibbets
• 金额: $ 2.49万
• 依托单位: UNIVERSITY OF NEW MEXICO
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6694971
• 关键词: Malacostraca; arid climate; carbon; ecosystem; leaf; nitrogen; nutrient bioavailability; phosphorus; plant ecology; predoctoral investigator; soil; soil sampling; stable isotope; water environment

DESCRIPTION (provided by applicant): Restoration of river and riparian ecosystems has become one of the most intense areas of research as human demands for freshwater from streams and rivers increase worldwide. Rivers are not only vital sources of water for agriculture and human consumption, but key areas of biodiversity. The middle Rio Grande river (MRG), which flows through central New Mexico, contains one of the most extensive riparian forests of native cottonwood remaining in the southwestern United States. The objectives of the proposed study are to examine the role of flooding on cottonwood nutrient allocation and riparian food web dynamics, and the role nutrient availability has on the physiological constraints of a key detritivore along the MRG. The effects of flooding on cottonwoods and food web structure will be measured at eight study sites along a 250 km reach of the MRG. Samples of cottonwood leaves, litter, soil, and soil arthropods will be collected over a two year period and analyzed for carbon (C), nitrogen (N), phosphorus (P), and natural abundance of 13C and 15N stable isotopes. C and N stable isotopes used in concert with C/N, C/P, and N/P ratios are important tools to assess nutrient cycling and food web structure and function in ecosystem studies. The effects of nutrient availability on terrestrial isopod nutrient allocation, growth, and reproduction will be measured during a series of experiments with treatments of low and high diet quality and different 13C and 15N stable isotope signatures. Although diet quality C/N has been studied in many organisms, the role of P is largely unknown. This research will contribute to better general understanding of ecosystem processes along riparian ecosystems in arid and semiarid regions and improved river management for water quality, biodiversity, and water use.

描述（由申请人提供）： 随着世界范围内人类对溪流和河流淡水需求的增加，河流和河岸生态系统的恢复已成为最激烈的研究领域之一。河流不仅是农业和人类消费的重要水源，也是生物多样性的关键地区。流经新墨西哥州中部的中格兰德河（MRG）是美国西南部现存最广泛的原生棉白杨河岸林之一。拟议的研究的目的是研究洪水对三角叶棉白杨养分分配和河岸食物网动态的作用，以及养分供应的作用对一个关键的食草动物沿着MRG的生理限制。洪水对三角叶杨和食物网结构的影响将在八个研究地点沿沿着250公里的MRG范围内进行测量。将在两年的时间内收集棉白杨树叶、凋落物、土壤和土壤节肢动物的样本，并分析碳（C）、氮（N）、磷（P）以及13 C和15 N稳定同位素的天然丰度。在生态系统研究中，碳、氮稳定同位素与C/N、C/P和N/P比值一起使用是评估营养循环和食物网结构与功能的重要工具。在一系列的实验中，低和高的饮食质量和不同的13 C和15 N稳定同位素签名的治疗，营养物质的可用性对陆地等足类动物的营养分配，生长和繁殖的影响进行测量。虽然饮食质量C/N已在许多生物中进行了研究，但P的作用在很大程度上是未知的。这项研究将有助于更好地了解生态系统过程沿着河岸生态系统在干旱和半干旱地区和改善河流管理的水质，生物多样性和用水。