LTER: Sevilleta (SEV) Site: Climate Variability at Dryland Ecotones

干旱地区已经占地球陆地面积的40%以上，而且在许多地方还在扩大。每年的气候差异极大地影响着这些旱地的生态和动植物的进化。新墨西哥州的塞维利亚长期生态研究场址包括五个主要的旱地生境或生态系统。这项研究将扩大这些生态系统的生态知识。指导性问题是：长期气候趋势如何驱动旱地生态系统的变化？特别是，一种类型的旱地生态系统是如何变成另一种类型的？科学家们将发展新的理论来预测会发生什么，例如，当降雨量减少时，他们将收集长期数据来验证他们的想法。他们还将做改变降雨模式的实验。该项目将使科学家能够改进对旱地的预测，改变我们对世界各地这些生态系统的理解。塞维利亚的科学家将通过各级学习活动招募和培训多样化的劳动力。这些包括许多校园课程，本科研究计划，跨学科的研究生和专业培训。该计划的社会影响包括与地方、区域和国家土地管理者的密切合作。Sevilleta LTER计划将测试气候均值和方差的变化如何独立和交互地影响旱地生态系统的动态和生态系统之间的过渡。研究活动将通过将长期观测和实验与理论、统计和模拟模型相结合，评估控制旱地人口、社区和生物群落过渡对气候变异性敏感性的机制的一般性。此外，塞维利亚生态系统和生态交错区的多样性将有助于对旱地转变的原因和后果进行比较研究，并促进新的跨地点合作。三个新的模型将吸收观测和实验结果，以预测气候变异对以下方面的影响：（一）基础植物物种时空轨迹驱动的过渡，（二）五个广泛分布的旱地生态系统的生态系统功能和服务，以及（iii）消费者动态通过气候对资源分配的影响。这个奖项反映了NSF的法定使命，并已被认为是值得支持，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。

Arid areas, which already comprise more than 40% of land on earth, are expanding in many places. Yearly differences in climate greatly affect the ecology and evolution of plants and animals in these drylands. The Sevilleta Long-Term Ecological Research (LTER) site in New Mexico includes five major dryland habitats or ecosystems. This research will expand ecological knowledge of those ecosystems. The guiding question is: How do long-term climate trends drive what happens in dryland ecosystems? In particular, how does one type of dryland ecosystem get turned into another type? Scientists will develop new theory to predict what happens when, for example, it rains less. They will collect the long-term data needed to test their ideas. They will also do experiments that change patterns of rainfall. This project will allow scientists to improve forecasts for drylands, transforming our understanding of these ecosystems worldwide. Scientists at Sevilleta will recruit and train a diverse workforce through activities at all levels of learning. These include many schoolyard lessons, undergraduate research programs, and interdisciplinary graduate and professional training. Societal impacts of the program include strong collaborations with local, regional, and national land managers.The Sevilleta LTER program will test how changes in climate mean and variance independently and interactively affect the dynamics of dryland ecosystems and the transitions between ecosystems. Research activities will evaluate the generality of mechanisms that control sensitivities of dryland populations, communities and biome transitions to climate variability by integrating long-term observations and experiments with theoretical, statistical, and simulation models. Moreover, the diversity of Sevilleta ecosystems and ecotones will enable comparative study of the causes and consequences of dryland transitions and foster new cross-site collaborations. Three novel models will assimilate observational and experimental results to forecast effects of climate variability on (i) transitions driven by the spatio-temporal trajectories of foundation plant species, (ii) ecosystem functions and services in five widespread dryland ecosystems, and (iii) consumer dynamics via climate impacts on the distribution of resources.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.