An Evaluation of Dispersal Distances of Two Treeline-Forming Species

随着环境的变化，植被必须适应，迁移或死亡。植物的迁移能力是植物地理学和生态学中最难解决的问题之一。遗传学的最新进展允许分析植物迁移潜力，以前是不可能评估的。在气候变化的情况下，植被带可能会发生变化。这些变化的幅度以及发生这些变化的速度可以由气候变化的速度和植被群落要素能够对这些变化作出反应的速度决定。植物传播种子的能力以及这些种子在气候变化下扎根的能力并不为人所知。这项研究将作出重要贡献的文献过渡区（生态交错带）之间的不同植被类型，最终回答的问题是否新的个人在一个广泛的植被过渡（高山树线）来自当地环境，如果他们长途跋涉。本研究将通过对阿拉斯加中南部白色云杉和山铁杉的基因组DNA进行微卫星（短序列）分析，来研究上述核心问题。这些人口将被用来确定是否新兵的树线更密切相关的近或远的人口，从而确定流行的长距离与短距离的传播。还将进行亲子关系分析，以估计实际的传播距离和方向。这项研究将有助于培养研究生和本科生，并加强美国和德国科学家之间的联系。将努力吸收代表性不足的学生群体参加研究。此外，通过与美国国家公园管理局和美国鱼类和野生动物管理局建立的联系，将促进与公众的互动，并将进一步加强这种联系。教育推广机会将包括向环境规划署人员作公开介绍，以及向基奈峡湾国家公园、基奈国家野生动物保护区的游客和得克萨斯州的当地学校传播主要调查结果。

As environments change over time, vegetation must adapt, migrate or die. The ability of plants to migrate is one of the more intractable and unanswered problems in both biogeography and ecology. Recent advances in genetics allow analysis of plant migration potential that previously had been impossible to assess. Under a changing climate, vegetation zones may shift. The magnitude of those shifts as well as the speed at which those shifts occur can be determined by both the rate of climate change and the rate at which elements of vegetation communities are able to respond to those changes. The ability of plants to disperse their seeds and for those seeds to become established under climate change is not well known. This research will make a vital contribution to the literature on transition zones (ecotones) among different vegetation types by finally answering the question whether new individuals at one wide-spread vegetation transition (the alpine treeline) are derived from the local environment versus if they are traveling long distances. The procedures developed to determine dispersal distances at treeline could also be extended to other ecotones or ecosystems.This study will examine the central questions above by employing microsatellite (short sequence) analysis of genomic DNA to identify the genetic sub-populations of both white spruce and mountain hemlock in southcentral Alaska. These populations will be used to determine if recruits to the treeline are more closely related to near or far populations, thereby determining the prevalence of long versus short distance dispersal. A parentage analysis will also be conducted to estimate actual dispersal distances and directions. This research will aid in the training of both graduate and undergraduate students and strengthen ties between scientists in the US and Germany. Efforts will be made to recruit under-represented groups of students in the study. Furthermore, interaction with the general public will be facilitated through the connections that have been made and will be further strengthened with the US National Park Service (NPS) and the US Fish and Wildlife Service. Educational outreach opportunities will include public presentations to NPS personnel as well as dissemination of key findings to visitors to the Kenai Fjords National Park, the Kenai National Wildlife Refuge, and to local schools in Texas.