基于Meta-分析的间伐强度对栎类天然林生长与更新的影响——对我国栎类天然林经营的启示

Influence of Thinning Intensity on Growth and Regeneration of Natural Oak Forests Based on Meta-analysis:Implications for Oak Forest Management in China

【目的】基于文献综述,研究间伐强度对栎类天然林生长与更新的影响,促进其科学经营和林分质量改善。【方法】检索已发表的相关文献数据,获得有效文献37篇和数据149条,采用Meta-分析方法探究间伐强度对栎类林分胸径年均生长量(mm·a^(−1))、林分蓄积年均生长量(m^(3)·hm^(−2)·a^(−1))和幼苗密度(株·100 m^(−2))的影响。【结果】中度(20%~39%)和强度间伐(≥40%)均能显著提高林分胸径生长量和蓄积生长量,特别是对幼龄林(≤20 a)和中龄林(21~40 a)效果显著,但对近熟林(41~60 a)和成熟林(>60 a)效果不显著;中度和强度间伐均能显著提高林分的幼苗密度,尤其对成熟林的效果最大;同时,在阳坡和下坡位或中坡位林分的间伐正效应值高于其它坡向和坡位。间伐激发幼龄林与中龄林生长和成熟林更新的效应持续时间约为10 a。【结论】中度以上间伐(≥20%)显著提高了栎类中幼龄林分的胸径和蓄积生长量以及成熟林幼苗密度,为持续促进上述林分生长与更新,其间伐间隔期应为10 a左右。研究结果可为我国栎类森林的可持续经营提供参考。

【Objective】Based on the literature review,the effects of thinning intensity on the growth and regeneration of natural oak forest were studied to promote its scientific management and the improvement of stand quality.【Method】In this study,a Meta-analysis approach was employed by carefully screening published relevant literature data(37 valid literatures;149 pairs of data),to investigate the impact of thinning intensity on the annual increment of diameter at breast height(DBH,mm·a^(−1)),annual increment of stand volume(m^(3)·hm^(−2)·a^(−1))and seedling density(individuals per 100 m^(2)).【Result】The findings found that moderate thinning(20%~39%)and strong thinning(40%)significantly promoted the increment of stand DBH and volume,particularly for the young-aged(20 a)and middle-aged forests(21~40 a).However,no significant effects were observed for the near mature forests(41~60 a)and mature forest(>60 a).Moderate to strong thinning intensity had a significant positive impact on seedling density enhancement,especially for the mature oak forests.Additionally,stands located on sunny slopes and bottom or middle slope positions exhibited more favorable responses to thinning across all three variables studied.The beneficial effects from thinning on the growth of young-to middle-aged oak forests and seedling density of mature oak forests generally lasted about ten years.【Conclusion】Moderate and above thinning intensity(20%)significantly enhanced the growth of young-to middle-aged oak forests and seedling density of mature oak forests.Approximate ten-year thinning interval was recommended to consistently improve productivity and recruitment of corresponding oak forests.This study provided valuable scientific guidance for formulating and implementing sustainable management measures for oak forests of China.