The Catalysis of Belowground Processes in Grazing Ecosystems

放牧生态系统地下过程的催化

• 批准号: 0318716
• 负责人: Douglas Frank
• 金额: $ 100万
• 依托单位: Syracuse University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0318716&HistoricalAwards=false
• 关键词: Catalysis; Belowground; Processes; Grazing; Ecosystems

A major challenge facing society is understanding the ecological processes contributing to atmospheric CO2 concentrations and how human land use practices influence atmospheric CO2 levels. Herbivores are known to strongly affect plant and soil carbon dynamics; but how grazers may determine the rate that carbon flows into and out of the soil remains unclear. In this study, the effects of grazing by elk and bison on carbon processes in Yellowstone National Park will be examined at three ecologically important time scales: (1) instantaneous rates of ecosystem CO2 exchange, (2) the rate that carbon flows through the plant - soil system during yrs 1-3 after carbon is assimilated by plants, and (3) 40-50 yr soil carbon storage. Yellowstone Park is one of the few remaining vestiges of a once widespread and stable grassland ecosystem that supported abundant migratory ungulates in prehistory, and thus can serve as a natural benchmark against which to compare grassland managed for livestock. With half of the earth's terrestrial surface area used as rangeland for large herbivores, the impact of ungulates on the global carbon cycle may be substantial. This research will contribute significantly to our understanding of factors that regulate carbon dynamics in grazed grassland.

社会面临的一个主要挑战是了解造成大气CO2浓度的生态过程以及人类土地使用做法如何影响大气CO2水平。 众所周知，食草动物会强烈影响植物和土壤碳动态;但食草动物如何决定碳流入和流出土壤的速率仍不清楚。 在这项研究中，麋鹿和野牛放牧对黄石国家公园碳过程的影响将在三个生态学上重要的时间尺度上进行研究：（1）生态系统CO2交换的瞬时速率，（2）碳被植物吸收后1-3年内通过植物-土壤系统的碳流动速率，（3）40-50年的土壤碳储存。 黄石公园是一个曾经广泛而稳定的草原生态系统的少数遗迹之一，在史前时期支持大量的迁徙有蹄类动物，因此可以作为一个自然基准来比较为牲畜管理的草原。 由于地球陆地面积的一半被用作大型食草动物的牧场，有蹄类动物对全球碳循环的影响可能是巨大的。 这项研究将有助于我们了解放牧草地碳动态的调控因素。