Dissertation Research: Genetic Diversity & Population Structure of Quercus ruba in Old Growth & Secondary Forests in Southern New England

Kesseli&Amp；Gerwein新英格兰的地貌在过去300年里发生了巨大的变化，最明显的是森林覆盖的缩小和最近的重新出现。虽然森林覆盖率已从19世纪中期高度分散分布的不到30%的低点增加到目前的65%，但这一瓶颈对这些群落物种的遗传多样性和结构的影响尚不清楚。19世纪30年代马萨诸塞州森林覆盖的记录为研究这些影响提供了机会。这些记录被用来确定马萨诸塞州四个地区的历史森林砍伐模式。DNA标记将被用来表征红栎树的遗传多样性和种群结构，红栎树是古林和次生林的优势树种。这项研究将描述老生长种群的遗传结构，确定二次生长种群是否具有较低的遗传多样性，并描述与历史砍伐森林记录相关的招募、扩散和结构模式。结果将有助于规划新英格兰森林的保护和区域发展，并将提供第一批数据，说明砍伐森林和森林退化的长期后果。新英格兰的历史视角可以作为描述这些长期影响的基线数据。这些数据将确定遗传多样性的关键避难所，并描述扩散模式和种群结构，这些都是保护管理的重要参数。

0073495Kesseli & GerweinThe landscape of New England has been drastically altered over the last 300 years, most obviously by the shrinking and recent reemergence of the forest cover. While forest cover has increased from a low of less than 30% in a highly fragmented distribution during the mid 1800s to the current 65%, nothing is known of the affect of this bottleneck on the genetic diversity and structure of the species of these communities. Records of Massachusetts forest cover in the 1830s provide an opportunity to examine these effects. These records are used to determine historic deforestation patterns in four areas of Massachusetts. DNA markers will be used to characterize the genetic diversity and population structure of Red Oak (Quercus rubra), a dominant tree of both old-growth and secondary forests. Thi study will describe the genetic structure of old-growth populations, determine whether secondary-growth populations have lower genetic diversity, and characterize the patterns of recruitment, dispersal and structure associated with historical deforestation records. Results will be useful in planning the conservation of New England forests and regional development and will provide the first data showing the long-term consequences of deforestation and forest degradation. The historical perspective of New England could be used as baseline data characterizing these long-term affects. These data will identify critical refugia of genetic diversity and characterize dispersal patterns and population structure, all important parameters for conservation management.