LTER: Long-term research on the dynamics of high-elevation ecosystems: A framework for understanding rates of ecological response to climate change

山脉为人类社会提供了重要的服务，也是多种生命形式的重要栖息地。它们也在迅速变化：气温正在上升，导致融雪时间、流向下游的水量以及无雪生长季节的长度发生变化。虽然世界上超过六分之一的人口生活在由积雪或冰川融化提供水源的河流流域，但我们对高山地区气候变化将如何影响生物多样性和水资源知之甚少。造成这种知识差距的一个原因是，崎岖的山地地形导致整个地形的温度变化模式发生巨大变化。Niwot Ridge (NWT) LTER是一个跨学科的研究项目，旨在研究复杂的地形如何与生物过程相互作用，以确定高海拔山区生态系统如何响应温度上升而发生变化。该项目记录了高山苔原、亚高山森林、高山湖泊和高山溪流的长期气候变化模式，以及生物、种群、群落和生态系统过程的相关响应。NWT LTER位于人口稠密的科罗拉多落基山脉的前山脉，具有独特的定位，可以产生直接影响大量人口的结果，同时吸引不同的受众参与生态，保护和山地科学。四十多年来，NWT LTER记录了研究地点在高度变化的降水模式下气温迅速上升。对这些气候变化的生物反应在速度和幅度上都有很大的变化。在NWT LTER VIII中，科学家将评估决定生物群和生态系统过程对温度上升的响应速率的生态机制。利用西北西北地区地形的复杂性，拟议的研究将研究温度暴露和其他非生物因素（如降水、生长季节长度、营养物质）的空间异质性如何调节对气温上升的生态反应速率，以及这些反应是否被整个物理模板（如生活史策略、群落动态、生态系统遗产）中发挥作用的生物过程加速或减弱。本研究的具体目标包括：(1)继续表征高海拔山区系统对气候变化的响应；(2)检验解释生态响应随气温上升速率变化的假设机制；(3)探索变暖响应速率的综合效应如何改变山区景观生态系统功能的预测。该研究项目提供了气候变化对山区生态系统影响的关键信息，为山区集水区及其为社会提供的资源的保护和管理提供了信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Mountains provide critical services for human society and important habitats for diverse forms of life. They are also changing rapidly: temperatures are rising, leading to shifts in the timing of snowmelt, the amount of water flowing downstream, and the length of the snow-free growing season. While more than one-sixth of the world’s population lives in river basins fed by snow or glacier melt, we know very little about how changing climate in high mountain areas will affect biodiversity and water resources. One reason for this knowledge gap is that rugged mountain terrain causes the patterns of changing temperature to vary dramatically across the landscape. The Niwot Ridge (NWT) LTER is an interdisciplinary research program that is investigating how complex topography interacts with biological processes to determine how high-elevation mountain ecosystems are changing in response to rising temperature. The project documents long-term patterns of climate change in alpine tundra, subalpine forest, mountain lakes, and alpine streams, as well as the associated responses of organisms, populations, communities, and ecosystem processes. Located in the populous Front Range of the Colorado Rocky Mountains, NWT LTER is uniquely positioned to generate results that will directly impact a large human population while engaging diverse audiences in ecology, conservation, and mountain science.For over four decades, the NWT LTER has documented rapidly rising temperatures amidst highly variable precipitation patterns at the study site. The biological responses to these changes in climate have been highly variable in both speed and magnitude. In NWT LTER VIII, scientists will evaluate the ecological mechanisms that determine the rates at which biota and ecosystem processes respond to rising temperature. Leveraging the topographic complexity of NWT terrain, the proposed research will examine how rates of ecological responses to rising air temperature are mediated by spatial heterogeneity in temperature exposure and other abiotic factors (e.g., precipitation, growing season length, nutrients), and if these responses are accelerated or attenuated by biotic processes that play out across the physical template (e.g., life history strategies, community dynamics, ecosystem legacies). The specific objectives of this research include (1) continuing to characterize how high-elevation mountain systems are responding to climate change, (2) testing hypothesized mechanisms that explain variation in the rate at which ecological responses track rising air temperature, and (3) exploring how the aggregated effects of variable rates of response to warming alter forecasts of ecosystem function across mountain landscapes. This research program provides critical information about the effects of climate change on mountain ecosystems that informs the conservation and management of mountain catchments and the resources they provide to society.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.