Doctoral Dissertation Research: Influence of Grazing Differences on Stream Geomorphology in Tallgrass Prairie Headwater Streams

博士论文研究：放牧差异对高草草原源头水流地貌的影响

• 批准号: 1303108
• 负责人: Melinda Daniels
• 金额: $ 1.55万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1303108&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Influence; Grazing

This dissertation project is about determining how various cattle and bison grazing practices influence sediment pollution and transport in grassland streams. Although grazing is a common land use practice, little is known about how different grazing practices affect sediment dynamics in the streams that drain these lands. Different species of grazing animals may produce significantly different sediment inputs to streams due to species-specific physiological and behavioral differences (e.g. wallowing, water demand, heat tolerance, vegetation preference). The researchers expect to find that grazed watersheds will have significantly higher sediment loads and higher frequencies and magnitudes of stream-bed sediment transport events because of increased hillslope erosion and stream-bed disturbance from trampling. Cattle grazed watersheds are predicted to have higher sediment loads than bison grazed watersheds because the behavioral habits of cattle are likely to produce more direct impacts and disturbances to channels. This project will advance the understanding of how species-specific impacts are driven by physiological and behavioral differences and contribute to a growing body of literature on biological engineering of landforms, or bio-geomorphology. Sediment is one of the major pollutants impacting streams in the United States. High sediment loads have led to reservoir filling throughout North America and the world and are implicated as a major source of oxygen depletion in coastal systems. In the Great Plains region of North America, increased runoff and hillslope erosion rates have led to decreased water quality and decreased the social and economic value of freshwaters. Results of this project will help to inform conservation, restoration, and management practices of grassland streams. In particular, the results could serve as the basis for revised grazing best management practices to address water quality issues within the region. The results will be presented at national and local science and policy-oriented academic conferences, presented to state and regional agencies charged with grazing land management, and published in peer-reviewed scientific and management oriented journals. As a doctoral Dissertation Research Improvement award, this project will provide support to enable a promising scholar. It will also provide training for a number of other students including several from underrepresented groups including minorities, women, and military veterans.

本论文旨在研究不同放牧方式对草地河流泥沙污染和迁移的影响。虽然放牧是一种常见的土地利用方式，但人们对不同放牧方式如何影响排干这些土地的溪流中的沉积物动态知之甚少。不同种类的放牧动物可能会因物种特定的生理和行为差异(如打滚、水分需求、耐热性、植被偏好)而向溪流产生显著不同的泥沙输入。研究人员预计，由于坡面侵蚀和践踏造成的河床扰动增加，放牧流域的泥沙负荷将显著增加，河床泥沙输送事件的频率和强度也会更高。据预测，放牧牛的流域的泥沙负荷比放牧野牛的流域高，因为牛的行为习惯可能会对航道产生更直接的影响和干扰。该项目将促进对特定物种的影响如何由生理和行为差异驱动的理解，并有助于增加关于地貌生物工程或生物地貌学的文献。泥沙是影响美国河流的主要污染物之一。高泥沙负荷导致整个北美和世界各地的水库被填满，并被认为是沿海系统氧气消耗的主要来源。在北美大平原地区，径流和山坡侵蚀率的增加导致水质下降，淡水的社会和经济价值降低。该项目的成果将有助于为草原溪流的保护、恢复和管理实践提供信息。特别是，结果可以作为修订放牧最佳管理做法的基础，以解决该区域内的水质问题。结果将在国家和地方科学和政策导向的学术会议上公布，提交给负责牧场管理的州和区域机构，并在同行评议的科学和管理导向的期刊上发表。作为博士学位论文研究改进奖，本项目将为培养有前途的学者提供支持。它还将为其他一些学生提供培训，其中包括几名来自少数族裔、妇女和退伍军人等代表性不足群体的学生。