LTER: Examining Long-term Southern Appalachian Ecosystem Dynamics through Interactions and Indirect Effects

阿巴拉契亚山脉南部的森林是北美树木、两栖动物、软体动物、鱼类、小龙虾、千足类、真菌和其他生物最多样化的聚集地。陡峭崎岖的地形与潮湿的气候相互作用，创造了多种栖息地，每种栖息地都对环境变化有自己的反应。自上一个冰河时代以来，这些森林一直在不断变化，人类通过美洲原住民的活动、欧洲人的殖民和边境农业活动、与酸降水有关的空气污染、现代土地利用做法、森林疾病和入侵物种的引入、火灾管理政策以及气候变化，在这些变化中发挥了作用。阿巴拉契亚山脉的森林提供了碳储存、养分循环、水和空气净化以及野生动物栖息地等生态系统服务。这项研究试图通过使用关于森林组成和结构、土壤特性、气候和径流的长期数据来描述和理解这个生态系统及其提供的服务是如何应对过去和正在发生的变化的。科学家们将继续增加长期数据，并将完成一项实验，以评估改变河滨走廊内植物群落的影响。这项研究的结果将指导土地管理机构和非政府组织的生态系统恢复和管理，并指导在多个治理级别上制定水质政策。科学发现将通过考韦塔倾听项目传达给当地社区。拟议的研究将为不同的学者、学生(中学、本科生和研究生)以及包括切诺基东部带在内的阿巴拉契亚南部社会的不同部分创造教育、培训和参与的机会。阿巴拉契亚南部的森林生物群正在对过去和正在发生的一系列干扰做出反应，包括极端水文气候增加、气温上升、生长季节延长和持续的城市化。将进行实验操作、观测研究和区域建模，以了解该生态系统如何对过去的干扰、土地利用变化和正在进行的气候变化做出反应。在地块和溪流尺度上进行的杜鹃花清除实验将通过减法检查观察到的本地入侵杜鹃的扩散如何改变森林和河岸生态系统。在长期地块中继续监测森林人口统计情况，将建立在代表350 000个树木年的20年树木人口统计数据的基础上。结合各种空间上广泛的气候和土壤数据，以及在其他地方合作收集的数据，这些记录将有助于检查竞争、场地特征、管理和过去干扰之间的相互作用。虽然实证工作已经记录了物种分布随时间的变化，作为不同和相互作用的物理、生物和人类因素的函数，但这项研究将依赖于分布式生态系统建模来检查跨尺度的时间和空间生态系统动力学。将使用区域水文-生态模拟系统框架进行生态水文模拟，以综合理解精细的生态过程，以检查森林变化在流域和区域尺度上的生态水文和生物地球化学效应。

The forests of the southern Appalachian Mountains are home to the most diverse assemblage of trees, amphibians, mollusks, fish, crayfish, millipedes, fungi and other organisms in North America. The steep rugged landscape interacts with a wet climate to create many kinds of habitats, each with its own responses to environmental change. These forests have been continually changing following the last ice age, and humans have played a role in those changes through the activities of Native Americans, colonization by Europeans and frontier farming activities, air pollution associated with acid precipitation, modern land use practices, the introduction of forest diseases and invasive species, fire management policies, and a changing climate. The forests of the Appalachian Mountains contribute ecosystem services such as carbon storage, nutrient cycling, water and air purification, and wildlife habitat. This research seeks to describe and understand how this ecosystem and the services it provides respond to past and ongoing change by using long-term data on forest composition and structure, soil characteristics, climate, and streamflow. The scientists will continue to add to the long-term data and will complete an experiment to assess the impacts of altering the plant community within the streamside corridor. Findings from this research will guide ecosystem restoration and management by land management agencies and Non-government organizations, and also guide the development of water quality policies at multiple levels of governance. Science findings will be communicated to the local community through the Coweeta Listening Project. The proposed research will create education, training and engagement opportunities for diverse scholars, students (middle school, undergraduate, and graduate), and diverse segments of southern Appalachian society including the Eastern Band of the Cherokee. The southern Appalachian forest biome is responding to a series of past and ongoing disturbances including increasing hydroclimate extremes, higher temperatures, lengthening growing seasons, and continuing exurbanization. Experimental manipulation, observational studies, and regional modeling will be conducted to understand how this ecosystem is responding to past disturbances, land use change, and ongoing climate change. The manipulative rhododendron removal experiment conducted at plot and stream-reach scales will examine, by subtraction, how forest and riparian ecosystems are altered by the observed spread of the native invasive rhododendron. Continued monitoring of forest demography in long-term plots will build upon 20 years of tree demographic data representing 350,000 tree-year. Coupled with diverse spatially extensive climate and soil data and with data collected collaboratively elsewhere, these records will help examine interactions among competition, site characteristics, management, and past disturbance. While empirical work has documented changes in species distributions through time as functions of diverse and interacting physical, biotic, and anthropic factors, this research will rely on distributed ecosystem modeling to examine temporal and spatial ecosystem dynamics across scales. Ecohydrologic modeling using the Regional Hydro-Ecologic Simulation System framework will be used to integrate understanding of fine-scale ecological processes to examine the ecohydrologic and biogeochemical effects of forest change at basin and regional scales.