Stream-Riparian Corridors - Disturbance, Linkages, and Resistance

众所周知，河岸(即溪流一侧)森林限制了溪流中的光供应和植物生长，同时提供了为溪流食物网提供燃料的有机物质。这种类型的横向相互作用在陆地和水生系统之间产生了密切的联系。在河流内部也有同样强大的上游和下游联系。通过改变陆地和水生要素之间的联系，森林采伐是一种干扰，影响到流域景观的山坡和溪流两个子系统。河岸过程可能决定了山坡干扰如何影响河流。在这个项目中，研究人员研究了河岸植被和溪流之间的相互作用如何影响溪流对森林砍伐的反应。他们通过对不同流域的比较研究，侧重于河岸植被的作用，在流域中，砍伐将移除上坡植被，但留下不同宽度的河岸地带。设计了两个研究要素，1)阐述河岸植被如何缓冲对河流的干扰，并组织陆地和热带生态系统之间的横向联系；2)在森林采伐后保留不同宽度的河岸植被时，量化河流中的梯度或“恢复距离”。响应变量包括溪流的物理模板(沉积物、光、热)、有机物动态(树叶分解)、生物地球化学(营养成分和浓度)以及生物成分。该项目将与NSF Coweeta LTER计划的成员直接互动，并进一步发展研究和教育基础设施。最后，结果将促进我们对干扰及其影响的理解，将研究与政策形成联系起来，并解决管理者对阿巴拉契亚南部流域的担忧。

Riparian (i.e., stream side) forests are known to restrict light availability and plant growth in streams while providing organic matter that fuels stream food webs. Lateral interactions of this type generate intimate links between terrestrial and aquatic systems. There are equally strong upstream and downstream linkages within streams. By altering the linkages between terrestrial and aquatic elements, forest harvest is a disturbance that influences both hillslope and stream subsystems of watershed landscapes. Riparian processes may dictate how hillslope disturbance influences streams. In this project, the investigators address how interactions between riparian vegetation and streams influence stream responses to forest clear-cutting. They focus on the role of riparian vegetation through comparative studies among watersheds where clear-cutting will remove upslope vegetation but leave riparian zones of differing widths. Two research elements are designed to, 1) address how riparian vegetation buffers disturbance to the stream and organizes lateral linkages between terrestrial and lotic ecosystems, and 2) quantify in-stream gradients or 'recovery distances' when different widths of riparian vegetation remain after forest harvest. Response variables include aspects of the stream's physical template (sediment, light, heat), organic matter dynamics (leaf breakdown), biogeochemistry (nutrient composition and concentration), and biotic composition.search. The project will interact directly with members of the NSF Coweeta LTER program and further development of the research and education infrastructure. Finally, results will advance our understanding of disturbance and its influences, link research and policy formation, and address manager's concerns for southern Appalachian watersheds.