Collaborative Research: Exploration of the mechanistic basis and biogeochemical implications of differential nutrient limitation among trophic levels

合作研究：探索营养级差异营养限制的机制基础和生物地球化学意义

• 批准号: 0816693
• 负责人: Curtis Richardson
• 金额: $ 32.14万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0816693&HistoricalAwards=false
• 关键词: Collaborative; Research; Exploration; mechanistic; basis

The structure and function of ecosystems is governed by patterns of nutrient limitation of plants and those organisms that consume plant remains, such as soil microbes. Often, plants and consumers are limited by the same nutrient. However, increasing evidence indicates that different nutrients can be limiters in some ecosystems, a situation known as differential nutrient limitation. This study examines why differential nutrient limitation occurs in some ecosystems but not others, and what the consequences are with respect to the utilization and storage of carbon. These questions will be tested using a network of fertilized plots in four wetlands from Rhode Island to Georgia, including both freshwater and saline systems. Standardized sampling at all sites will ensure comparable measurements of plant and microbial productivity, phosphorus cycling and ecosystem metabolism. It is expected that differential nutrient limitation will occur in ecosystems with higher rates of phosphorus mineralization and will yield less carbon storage. This study has implications for ecosystem management and provides a conceptual framework to integrate ecological studies at multiple scales by understanding how nutrient ratios affects the biogeochemical cycles that govern ecosystem energetics. It includes a commitment to students from under-represented groups, including American Indians and African Americans, through a research mentoring program.

生态系统的结构和功能取决于植物和那些消耗植物遗骸的生物（如土壤微生物）的营养限制模式。通常，植物和消费者受到相同营养素的限制。然而，越来越多的证据表明，在某些生态系统中，不同的养分可能是限制因素，这种情况被称为差别养分限制。本研究探讨了为什么不同的养分限制发生在某些生态系统，而不是其他人，以及什么后果是关于碳的利用和储存。这些问题将使用从罗得岛到格鲁吉亚的四个湿地的施肥地块网络进行测试，包括淡水和盐水系统。 所有地点的标准化取样将确保对植物和微生物生产力、磷循环和生态系统新陈代谢进行可比测量。预计在磷矿化率较高的生态系统中将出现不同的养分限制，并产生较少的碳储存。这项研究的生态系统管理的影响，并提供了一个概念性的框架，以整合生态研究在多个尺度上了解营养比例如何影响生态系统能量的地球化学循环。它包括通过一个研究指导计划，对来自代表性不足群体的学生，包括美洲印第安人和非洲裔美国人的承诺。