摘要
【目的】构建栎类天然林最大密度线,探究栎类天然林自稀疏规律,从理论上丰富种群生态学,为天然林林分密度管理与控制提供理论参考。【方法】以湖南省265块栎类天然林连续清查样地为研究对象,对现有林分密度指数进行改进,采用分位数回归和随机前沿分析评估Reineke林分密度指数和改进林分密度指数在构建栎类天然林最大密度线方面的适用性,并对不同林分类型栎类天然林的自稀疏特点进行分析。【结果】与Reineke林分密度模型相比,改进林分密度模型的预测误差显著降低(P<0.05),模型以林分平均胸径和优势树种平均高为基础变量,能够更好诠释林分自稀疏的内涵;随机前沿分析方法在模拟天然林最大密度线模型方面更加客观且精度较高,分位数回归方法也可提供有价值的补充;天然混交林自稀疏过程受林分平均胸径和优势树种平均高的共同影响,林分平均胸径越大,自稀疏速率越快;林分优势树种平均高越大,林分可容纳株数越多。天然林自稀疏速率在不同类型林分之间存在显著差异(P<0.05),栎类相对纯林的自稀疏速率更快、死亡率更高。【结论】构建栎类天然林最大密度线,探究其自稀疏规律,可为栎类天然林自稀疏状态的判别提供定量依据,有助于精准提升栎类天然林林分质量,更好把握天然林的自稀疏动态。
【Objective】To construct the maximum density-size line and explore the self-thinning rule of oak natural forest,the study aims to enrich the theory of population ecology and provide a theoretical reference for the management and control of forest stand density in natural forests.【Method】Using data from 265 continuous inventory plots of oak mixed forests in Hunan Province,the stand density index was improved.The applicability of Reineke density index and the improved density index in constructing the maximum density line of oak natural forests was evaluated using quantile regression and stochastic frontier analysis.The self-thinning rule of oak natural forest with different stand types were also analyzed.【Result】Compared with Reineke’s stand density model,the improved stand density model significantly reduced prediction errors(P<0.05).The improved stand density model,based on mean diameter at breast height and mean height of dominant tree species,could better interpret the meaning of self-thinning in forest stands.The stochastic frontier model was more objective and accurate in simulating the maximum density-size model,and the quantile regression method can also provide a valuable supplement.The self-thinning process of natural mixed forest was determined by the average diameter and the average height of dominant tree species.The larger the mean stand diameter was,the faster the rate of self-thinning was.The higher the average height of dominant tree species,the more plants could be accommodated.Moreover,the rate of self-thinning showed significantly different among different types of oak stands(P<0.05),and the oak pure forest showed a faster rate and a higher mortality.【Conclusion】The study of maximum density-size model and self-thinning rule can provide a quantitative basis for the identification of the self-thinning state of the oak natural forest,and help to improve the quality of the oak natural forest and grasp the dynamics of the self-thinning.
作者
龙时胜
曾思齐
杨盛扬
Long Shisheng;Zeng Siqi;Yang Shengyang(Central South University of Forestry&Technology,Changsha 410004;Key Laboratory of National Forestry and Grassland Administration on Forest Resources Management and Monitoring in Southern China,Changsha 410004)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2023年第9期13-22,共10页
Scientia Silvae Sinicae
基金
湖南省教育厅科学研究项目(22B0255)
林业公益性行业科研专项(201504301)。
关键词
自稀疏规则
最大密度线
林分密度指数
天然林
栎类
self-thinning rule
maximum density-size line
stand density index
natural forest
oak
