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。气候的年差异极大地影响了这些旱地动植物的生态和进化。新墨西哥州的塞维利亚塔长期生态研究（LTER）地点包括五个主要的旱地栖息地或生态系统。这项研究将扩大这些生态系统的生态学知识。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，一种旱地生态系统是如何转变成另一种类型的？科学家们将开发新的理论来预测，例如，当降雨减少时会发生什么。他们将收集检验他们的想法所需的长期数据。他们还将做一些改变降雨模式的实验。这个项目将使科学家能够改进对旱地的预测，改变我们对全球这些生态系统的理解。塞维利亚塔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，本科生研究项目，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强有力合作。塞维利亚LTER项目将测试气候均值和方差的变化如何独立地、相互地影响旱地生态系统的动态以及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、统计和模拟模型结合起来，评估控制旱地人口、群落和生物群落过渡对气候变率敏感性的机制的一般性。此外，塞维利亚生态系统和过渡带的多样性将有助于对旱地过渡的原因和后果进行比较研究，并促进新的跨站点合作。三个新的模型将吸收观测和实验结果来预测气候变率对以下方面的影响：(i)基础植物物种时空轨迹驱动的过渡；（ii）五个广泛分布的旱地生态系统的生态系统功能和服务；（iii）通过气候对资源分布的影响而产生的消费者动态。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。

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.