采伐强度对马尾松中龄林林分状态的影响
The impact of logging intensity on the stand state of middle-aged Pinus massoniana plantations
[目的]对比分析不同采伐强度对马尾松中龄林林分状态的影响，旨在为马尾松人工林的科学经营提供理论依据。[方法]本研究以中龄阶段马尾松人工林为研究对象，设置了5种采伐强度(0％、10％、20％、30％、40％)，从结构、活力和多样性3个方面选取9个典型指标构建林分状态评价体系，并利用单位圆方法检验了采伐强度对马尾松中龄林林分状态的短期影响。[结果](1)林分密度、林木健康、树种组成和树种多样性这4个林分状态指标对采伐强度响应相对敏感，采伐后短期内可以显著改善(P＜0.05);而树种均匀度、胸径分布、树高分布、林木优势度和林分长势等林分状态指标对采伐强度的响应相对较差，需要更长时间的恢复。(2)马尾松中龄林林分状态综合评价指数随采伐强度呈先增加后降低的趋势，约30％采伐强度下林分状态最理想。(3)单位圆方法与主成分分析对林分状态评价结果呈极显著线性相关(R2=0.909，P＜0.001)，但单位圆方法较主成分分析更为直观且反应更敏感。[结论]采伐强度显著影响马尾松中龄林的林分状态，中度采伐(约30％采伐强度)有助于改善林分状态。单位圆方法能够科学有效地反映采伐强度对马尾松中龄林林分状态的短期影响，并对具体森林经营措施制定具有较高的指导意义。
[Objective]This investigation aimed to secure a theoretical foundation on which to inform the judicious management of Pinus massoniana plantations by assessing the repercussions that varied logging intensities have on the stand state of middle-aged P.massoniana plantations and provide invaluable guidance for the formulation of specific forest management strategies.[Method]Five distinct logging intensity categories were delineated(0％,10％,20％,30％,40％).To construct a robust stand state evaluation framework,nine representative indicators across the three dimensions of structure,vitality,and diversity were selected.Employing the unit circle method first,we scrutinized the short-term ramifications of logging intensity.[Result]The findings revealed that:(1)Four indicators—stand density,tree health,species composition,and species diversity—exhibited pronounced sensitivity to logging intensity.These four exhibited significant improvement in the short-term post-logging(P＜0.05).Conversely,the indicators of species evenness,diameter distribution,height distribution,tree dominance,and stand growth exhibited a more subdued response to logging intensity.These five necessitated an extended period to begin to improve.(2)The comprehensive evaluation index values measuring the stand state of middle-aged P.massoniana plantations initially ascended,but then subsequently descended,as logging intensity escalated.The stand state zenith was pinpointed at an approximate 30％logging intensity.(3)A highly significant linear correlation emerged between the unit circle method results and the principal component analysis results in evaluating stand state(R^2=0.909,P＜0.001),although the unit circle method proved to be more intuitive and responsive.[Conclusion]In summation,logging intensity exerted a substantial influence on the stand state of middle-aged P.massoniana plantations,with moderate logging(circa 30％logging intensity)enhancing the stand state the most.The unit circle method proficiently and effectively illuminated the short-term effects of logging intensity on the stand dynamics of middle-aged P.massoniana plantations.
涂静;柴宗政;赵中文;
贵州大学林学院 贵州 贵阳 550025;贵州大学林学院 贵州 贵阳 550025;贵州省织金县国有桂花林场 贵州 织金 552100;
plantation logging intensity stand state unit circle method principal component analysis
96-105 / 10
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