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，也是各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，导致积雪融化的时间、下游的水量以及无雪生长季的长度发生了变化。虽然世界上超过六分之一的人口生活在积雪或冰川融化的河流流域，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。造成这种认识差距的一个原因是，崎岖的山区地形导致整个地区的温度变化模式有很大的不同。尼沃特山脉(Niwot Ridge)LTER是一项跨学科研究计划，旨在研究复杂的地形与生物过程如何相互作用，以确定高海拔山区生态系统如何随着气温上升而发生变化。该项目记录了高山冻原、亚高山森林、山湖和高山溪流气候变化的长期模式，以及生物、种群、群落和生态系统过程的相关响应。NWT LTER位于科罗拉多州落基山脉人口密集的前沿山脉，具有独特的优势，能够产生直接影响大量人口的成果，同时吸引不同的受众参与生态、保护和山地科学。40多年来，NWT LTER记录了研究地点在高度变化的降水模式中气温迅速上升的情况。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，科学家们将评估决定生物群和生态系统过程对气温上升做出反应的速率的生态机制。利用西北地区地形的复杂性，拟议的研究将研究温度暴露的空间异质性和其他非生物因素(如降雨量、生长季长度、营养物质)如何调节生态对气温上升的反应速率，以及这些反应是否被跨越物理模板的生物过程(如生活史战略、群落动态、生态系统遗产)加速或减弱。这项研究的具体目标包括：(1)继续描述高海拔山区系统如何对气候变化作出反应，(2)测试解释生态反应随气温上升的速率变化的假想机制，以及(3)探索对气候变暖的不同反应速率的综合影响如何改变整个山区景观生态系统功能的预测。这项研究计划提供了有关气候变化对山区生态系统影响的关键信息，为山区集水区及其提供给社会的资源的保护和管理提供了信息。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.