Implications of Ecotypic Variation for the Response of Tundra Plants to Climate Change

“该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。“本项目将研究生态类型分化的作用，即，植物对环境的局部适应，调节并可能限制植物物种对气候变化的反应。1979 ~ 1980年在阿拉斯加北方进行了两个相互移植试验，一个是沿沿着梯度排列的羊胡子草，另一个是沿沿着梯度排列的睡莲。这两个实验都表明，在这两个北极植物物种种群间的遗传分化。在拟议的研究中，PI将重新调查两项相互移植研究，以询问气候变化是否已经导致？不匹配？生态类型和它们的原始环境之间的联系，发出一个信号？适应滞后来应对气候变化。将在每个移植部位进行一系列性能（健康相关）测量（3个部位x 3个人群，D. octopetala和E. vaginatum），包括生存、生长和繁殖。将使用两个物种的芽种群的大小分类矩阵建模来测量生长。还将测量相关的生理参数，包括光合作用、碳同位素比和组织氮含量，以解释种群和地点之间的性能差异。将采用多因素ANOVA或对数似然分析（适当时采用重复测量）分析数据。数据将通过Toolik LTER数据库存档。

"This award is funded under the American Recovery and Reinvestment Act of 2009(Public Law 111-5)."This project will examine the role of ecotypic differentiation, i.e., local adaptation of plants to the environment, in modulating and potentially limiting the response of a plant species to climate change. Two reciprocal transplant experiments were set up in northern Alaska in 1979-80 to examine ecotypic differentiation; one with Eriophorum vaginatum arrayed along a latitudinal gradient, and one with Dryas octopetala arrayed along an elevational gradient. Both experiments demonstrated strong between-population genetic differentiation in these two arctic plant species. In the proposed study, the PIs will re-census the two reciprocal transplant studies to ask whether climate change has already resulted in a ?mismatch? between ecotypes and their original environment, signaling an ?adaptational lag? in response to climate change. A suite of performance (fitness-related) measures will be made in each of the transplant sites (3 sites x 3 populations for D. octopetala, and 6 sites x 6 populations for E. vaginatum), including survival, growth, and reproduction. Growth will be measured using size-classified matrix modeling of shoot populations for both species. Relevant physiological parameters will also be measured, including photosynthesis, carbon isotope ratios, and tissue nitrogen content, in order to explain performance differences among populations and sites. The data will be analyzed with multi-way ANOVAs or loglikelihood analyses, with repeated measures, as appropriate. Data will be archived through the Toolik LTER database.