Dissertation Research: The Genetic Consequences of Self- thinning in Stands of Loblolly Pine

火炬松（Pinus taeda）占主导地位的早期 北卡罗来纳州皮埃蒙特的连续森林。 资源的稀缺，特别是光的稀缺， 松树林经历间伐：随着树木的生长 更大，对光的竞争升级， 矮个子、有阴影的个体死亡率很高。 一些调查人员发现，在一些森林中， 树种，遗传杂合性在幼龄时较低 站在高处的老看台上。 这种趋势是 这可能是挑选更纯合的 个体，当林分经历间伐。 研究 以确定这些人是否与 高杂合性不太可能死亡， 林分存活个体的平均杂合度 反映了资源竞争的激烈程度， 由初始林分密度决定。 这项研究旨在探索自然过程 影响着林分的遗传结构。 与松树种植园相反， 可能会保持较高的遗传多样性， 杂合子个体通过稀疏的优势 茂密的树林 天然林分的遗传效应 间伐可能对森林产生重要影响 管理工作旨在最大限度地提高树木的活力， 森林生产力。

Loblolly pine (Pinus taeda) dominates the early successional forests of the North Carolina Piedmont. Scarcity of resources, especially light, causes the stands of pine to undergo thinning: as the trees grow larger, competition for light escalates and the shorter, shaded individuals suffer high mortality. Several investigators have found that in some forest tree species, genetic heterozygosity is low in young stands and high in older stands. This trend is the likely result of the culling of the more homozygous individuals when the stands undergo thinning. Research is proposed to determine whether those individuals with high heterozygosity are less likely to die, and whether the average heterozygosity of the survivors in a stand reflects the intensity of competition for resources as determined by initial stand density. This research proposes to explore the natural processes which influence genetic structure in forest stands. Natural forest stands, as opposed to pine plantations, may maintain higher genetic diversity as a likely benefit of heterozygous individuals through thinning of dense stands. The genetic effects of natural stand thinning could have important implications for forest management efforts aimed at maximizing tree vigor and forest productivity.