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。”该项目将研究生态型分化，即植物对环境的局部适应，在调节和潜在限制植物物种对气候变化的反应方面所起的作用。1979-1980年在阿拉斯加北部建立了两个相互移植的实验，以研究生态型的分化；一个是阴道绒螯蟹沿着纬度排列，另一个是章鱼沿着海拔梯度排列。这两个实验都证明了这两种北极植物种群间的遗传分化很强。在拟议的研究中，私人投资机构将重新普查这两项相互移植的研究，以询问气候变化是否已经导致错配？生态型与其原始环境之间的关系，标志着一种适应滞后？以应对气候变化。将在每个移植地点(章鱼3个地点×3个种群，阴道毛虫6个地点×6个种群)制定一套性能(与健康有关的)措施，包括存活、生长和繁殖。将使用两个物种的枝条种群的大小分类矩阵模型来测量生长。还将测量相关的生理参数，包括光合作用、碳同位素比率和组织氮含量，以解释种群和地点之间的表现差异。数据将用多因素方差分析或对数似然分析进行分析，并酌情进行重复测量。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.