A 41-year-old bottomland hardwood plantation experiment located in southeastern Arkansas was revisited in 2017 to evaluate basal area increment (BAI) of four oak species [cherrybark oak (Quercus pagoda Raf.), swamp chestnut oak (Q. michauxii Nutt.), Nuttall oak (Q. texana Buckl.), and water oak (Q. nigra L.)] planted in monoculture in relation with species, spacing, thinning, and neighborhood competition. Species had a significant effect on BAI (P = 0.04), with cherrybark oak and Nuttall oak demonstrating the greatest (21.5 ± 2.5 cm2 year−1) and lowest (12.7 ± 2.9 cm2 year−1) growth rates, respectively, whereas BAI declined significantly with increasing competition (P = 0.03). However, rates of growth decline with competition did not differ between species (P > 0.05 for competition × species term), and thinning and spacing treatments had no effect on BAI (P > 0.05). We recommend that repetitive thinning, rather than a single thinning, would be appropriate to maintain a positive impact on oak growth. Managing stand density would not only provide opportunities for improving timber production, but also would enhance ecological benefits (e.g., wildlife habitat) through diversification of structure within monoculture plantations.

中文翻译：

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低地硬木人工林中四种橡树树种的树层生长：对造林处理的启示

2017 年重新审视了位于阿肯色州东南部的一个 41 年历史的低地硬木人工林试验，以评估四种橡木树种 [樱桃树橡木 (Quercus pagoda Raf.)、沼泽板栗橡木 (Q. michauxii Nutt.) 的基底面积增量 (BAI) 、Nuttall 橡树 (Q. texana Buckl.) 和水橡树 (Q. nigra L.)] 在与物种、间距、间伐和邻域竞争相关的单一栽培中种植。物种对 BAI 有显着影响（P = 0.04），樱桃皮橡木和 Nuttall 橡木的增长率分别最高（21.5 ± 2.5 cm2 year-1）和最低（12.7 ± 2.9 cm2 year-1），而 BAI 下降随着竞争的加剧（P = 0.03）。然而，随着竞争而下降的增长率在物种之间没有差异（竞争×物种项 P > 0.05），间伐和间隔处理对 BAI 无影响（P > 0.05）。我们建议重复间伐而不是单次间伐，以保持对橡木生长的积极影响。管理林分密度不仅会为提高木材产量提供机会，而且还会通过单一种植园内结构的多样化来提高生态效益（例如野生动物栖息地）。