International Research Fellowship Program: Plant Invasions and Species Range Shifts in the Face of Climate Change: An Experimental and Modeling Study in Mediterranean Ecosystems

[00:50 . 98]国际研究奖学金计划使美国科学家和工程师能够到国外进行9至24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项将支持Miguel Schwartz博士与以色列特拉维夫大学的Marcelo Sternberg博士以及北卡罗来纳州杜克大学的James S. Clark博士共同开展为期24个月的研究。气候变化正以多种方式改变着自然生态系统。物种范围的变化和生物入侵是这些影响中最重要的两个。这些过程与区域生物多样性减少、生态系统功能改变和物种相互作用重组有关。由于物种范围转移和外来物种入侵的机制具有共同的特征，因此PI和宿主提出了一个实验和建模框架，使他们能够在高度多样化的生态系统中进行研究。了解物种（无论是外来物种还是邻近地区的外来移民）入侵自然群落的潜力是预测物种、群落和生态系统在不断变化的未来变化的关键。地中海盆地是一个生物热点，位于温带和干旱地区的交界处。区域气候模式表明降水显著减少，对自然系统的影响未知。这项研究提出的主要问题是：考虑到这种剧烈的气候变化，植物群落可能会是什么样子？以色列具有很强的降水梯度，为本研究提供了理想的地点，可以在短距离内评估不同的地点。Sternberg博士是研究这一梯度的国际努力（GLOWA约旦河项目）的协调员之一。PI将与他的东道主合作，通过确定选定的物种是否可以入侵沿着干旱梯度的两个地点的自然群落来调查这项研究的主要问题。在这两个代表地中海和半干旱气候的地点，他们将操纵降雨量来模拟本世纪中叶的预测降水。在两个地点的一系列微站点上，在两种降水处理下，他们将评估种植入侵者（包括外来物种和邻近地区物种）相对于彼此，相对于种植的本地物种和周围的本地社区的成功。植物性能将通过几种测量方法进行量化，并对所选物种的可量化物种性状进行研究。他们将使用复杂的采样技术来测量生物和环境协变量，以更好地了解微点和时间的变化范围。PI与国内主机合作，建议使用分层贝叶斯建模框架来分析结果。这种方法允许使用来自操作实验的数据以及利用来自GLOWA项目的长期监测数据。他们将通过使用该模型来预测在现实气候情景下被测试物种（及其基于特征的类似物）的区域入侵，从而扩大他们的结果。该项目的结果和相关的物种特征数据库将通过一个现有的网站进行共享，并对结果进行分析，面向学术界的科学家和广大公众。

0705098SchwartzThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Miguel Schwartz to work with Dr. Marcelo Sternberg at Tel Aviv University in Israel, and with Dr. James S. Clark at Duke University in North Carolina.Climate change is altering natural ecosystems in diverse ways. Shifts in species ranges and biological invasions are two of the most consequential of these impacts. These processes are associated with regional reductions in biodiversity, altered ecosystem function and reorganized species interactions. Because the mechanisms of species range shifts and exotic species invasions share common characteristics, the PI and host propose an experimental and modeling framework that allow them to study both in a highly diverse ecosystem. Understanding the potential of species (be they exotics or immigrants from a neighboring region) to invade natural communities is key to predicting species, community, and ecosystem changes in a changing future. The Mediterranean basin, a biological hotspot, lies at the border between temperate and arid regions. Regional climate models indicate a significant reduction in precipitation with unknown consequences for natural systems. The main question this study asks is: what might plant communities look like, given this dramatic climatic change. With its strong precipitation gradient, Israel provides an ideal area to locate this study, allowing assessment of diverse sites within a short distance. Dr. Sternberg is one of the coordinators of an international effort (GLOWA Jordan River Project) investigating this gradient. The PI will work with his host to investigate the study's main question by determining whether selected species can invade natural communities at two sites along the aridity gradient. At these two sites, representing Mediterranean and semi-arid climates, they will manipulate rainfall to simulate predicted precipitation in the middle of the century. Across a range of microsites at both sites, and at two precipitation treatments, they will assess the success of planted invaders (both exotic and neighboring region species) relative to each other, to planted natives, and to the surrounding native community. Plant performance will be quantified via several measures and investigate quantifiable species traits of the selected species. They will measure biotic and environmental covariates using a sophisticated sampling technique to better understand the range of variation across microsites and time. Working with the domestic host, the PI proposes to use a hierarchical Bayesian modeling framework to analyze the results. This approach allows use of the data from the manipulation experiment as well as to exploit long term monitoring data from the GLOWA Project. They will scale their results by using the model to predict regional invasions of tested species (and their trait-based analogues) under a realistic climate scenario. Results of both the project and the associated species traits database will be shared through an existing website with analysis of results geared to both academic scientists and the public at large.