This study examined the influence of midstory removal applied 9 years prior to a shelterwood establishment cut on survival, growth, and competitive status of black oak (Quercus velutina Lam.), white oak (Quercus alba L.), and an oak competitor, red maple (Acer rubrum L.), immediately before and at 6 years following shelterwood cutting on intermediate productivity sites in the Central Hardwood Forest Region. We also examined height and density distributions of the regenerating cohort to quantify seedling establishment and to elucidate relative oak competitiveness at each time period. Although oak seedlings were taller 9 years after midstory removal than in undisturbed controls, the midstory removal treatment reduced the frequency of free-to-grow oaks (relative to understory competitors) and increased the size of red maple and relative density of large competitors. Height growth of all three species following establishment cutting was increased by prior midstory removal and dependent on seedling competitive position immediately before shelterwood establishment. Additionally, we observed increased seedling densities 6 years following shelterwood establishment cutting and greater white oak seedling establishment when midstory removal preceded the shelterwood treatment.

中文翻译：

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砍伐中间材有利于生长，但降低了lt木定植前后的橡木生产竞争力。

这项研究调查了砍伐阔叶树前9年实施的去除中间层对黑橡树（Quercus velutina Lam。），白橡树（Quercus alba L.）和橡树竞争对手红树的存活，生长和竞争状态的影响。枫（宏碁癣菌L.），在中央硬木森林地区的中等生产力站点砍伐阔叶林之前和之后的6年。我们还检查了再生群体的高度和密度分布，以量化幼苗的建立并阐明每个时期的相对橡树竞争力。尽管中层去除后橡树幼苗比未受干扰的对照高9年，但中层去除处理减少了自由生长的橡树（相对于林下竞争者）的发生频率，并增加了红枫的大小和大型竞争者的相对密度。砍伐定居点后，所有三个树种的高度生长都通过事先清除中层而增加，并且取决于苗木定居前的幼苗竞争地位。另外，