基于林分密度控制图的闽楠人工林全周期经营目标树密度研究

Study on target tree density of Phoebe bournei plantation in full cycle management based on stand density control chart

【目的】目标树密度作为近自然森林经营的重要经营参数,确定林分不同发展阶段的目标树密度可为近自然森林经营提供理论依据。【方法】以湖南省永州市金洞林场闽楠人工林为研究对象,基于连续6 a调查得到的9块固定标准地数据54个,临时样地数据10个,共64个样本量,建立等树高线、最大密度线、等疏密度线、等直径线和自然稀疏线等5个密度控制图的相关模型,通过这5个模型编制闽楠人工林林分密度控制图,利用林分密度控制图,得到闽楠人工林各林分发展阶段的目标树密度。【结果】在保证实用性的前提下将闽楠人工林的生长过程分为五个发展阶段:当闽楠人工林处于建群阶段和竞争生长阶段时,林内生长的闽楠尚不满足目标树选择的标准,所以这两个阶段不选择目标树;当闽楠人工林进入质量选择阶段,此时闽楠满足目标树的选择标准,可以开始选择目标树。在开始目标树选择后的三个阶段,目标树密度分别为:质量选择阶段360~720株/hm^(2),目标树生长阶段165~330株/hm^(2),林分蓄积生长阶段65~130株/hm^(2)。【结论】运用林分密度控制图研究闽楠人工林各林分发展阶段的目标树密度,为目标树密度的确定提供新方法,为金洞林场闽楠人工林近自然经营提供理论依据,该方法同样适用于其他树种的目标经营。

【Objective】Target tree density is an important management parameter of near natural forest management.The determination of target tree density at different development stages can provide a theoretical basis for near natural forest management.【Method】Taking Phoebe bournei plantation in Jindong forest farm of Yongzhou city,Hunan province as the research object.Through six years of continuous investigation,we obtained 54 data of 9 fixed standard plots and 10 data of temporary sample plots,with a total of 64 sample sizes.Five models of contour line,equal diameter line,maximum density line,equal density line and natural sparse line were established,through these five models,the density control system of Phoebe bournei plantation was worked out.Based on the stand density control chart,the target tree density of Phoebe bournei plantation in each stage was obtained.【Result】On the premise of ensuring practicability,the growth process of Phoebe bournei plantation is divided into five stages.When Phoebe bournei plantation is in the stage of group building and competitive growth,the growth of Phoebe bournei in the forest does not meet the selection criteria of target tree,so the target tree is not selected in these two stages.When Phoebe bournei plantation enters the stage of quality selection,Phoebe bournei can meet the selection criteria of target tree to start selecting the target tree,the target tree density of the three stages after the start of target tree selection are are:quality selection stage 360-720 plants·hm^(2),target tree growth stage 165-330 plants·hm^(2),and stand volume growth stage 65-130 plants·hm^(2).【Conclusion】The density control chart was first used to study the target tree density of Phoebe bournei plantation in each development stage,which provided a new method for determining the target tree density and a theoretical basis for the near natural management of Phoebe bournei plantation in Jindong forest farm.This method is also suitable for the target management of other tree species.