杉木人工林林分叶面积动态变化规律  

Dynamic change of stand leaf area for Chinese fir plantation

作　　者：屈彦成 江怡航 陈涵玥 张建国[1] 张雄清[1,2] QU Yancheng;JIANG Yihang;CHEN Hanyue;ZHANG Jianguo;ZHANG Xiongqing(State Key Laboratory of Efficient Production of Forest Resources,Key Laboratory of Tree Breeding and Cultivation of the National Forestry and Grassland Administration,Research Institute of Forestry,Chinese Academy of Forestry,Beijing 100091,China;Collaborative Innovation Center of Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]中国林业科学研究院林业研究所,林木资源高效生产全国重点实验室,国家林业和草原局林木培育重点实验室,北京100091 [2]南京林业大学南方现代林业协同创新中心,南京210037

出　　处：《生态学报》2024年第13期5609-5620,共12页Acta Ecologica Sinica

基　　金：国家自然基金面上项目(31971645)。

摘　　要：叶面积与树木生长密切相关,是量化树木潜在生产能力的重要因子,其动态变化直接驱动林木生长的变化,但目前学者们对于林分叶面积动态变化规律却持有不同的观点。以亚热带不同气候区杉木人工林为研究对象,基于54个样地,共144株解析木的数据,采用6种生长方程通过非线性混合效应模型分别构建杉木单木叶面积模型和林分密度模型,将二者相乘得到林分叶面积动态变化模型,进而探究其动态变化规律。结果表明,以样地作为随机效应因子,考虑Logistic方程a参数上的随机效应,同时不考虑异方差结构的混合模型(样地水平)作为单木叶面积的最优模型;以地区作为随机效应因子,考虑Logistic方程a参数上的随机效应,同时不考虑异方差结构的混合模型(总体平均水平)作为林分密度的最优模型;林分叶面积动态变化呈单峰形式,幼龄阶段增长较快,达到峰值后迅速下降,之后下降幅度减少。本研究在考虑林分自然稀疏的前提下从生长模型的角度证明了杉木林分叶面积动态变化呈单峰型,而非达到顶峰后保持不变,同时也表明林分叶面积达到顶峰后下降是由于林分密度的降低引起的。研究结果对于合理经营不同气候梯度的杉木人工林具有重要意义。Leaf area is an important factor for quantifying the potential production of trees because it is closely related to tree growth.The dynamic changes in leaf area directly drive the change of tree growth.At present,scholars hold varying views on the dynamic changes in stand leaf area.Some scholars proposed a classical hypothetical trend that leaf area of a stand showed a more or less constant level after the initial peak.On the contrary,other scholars proposed another hypothetical trend:i.e.,the stand leaf area showed a single peak maximum of leaf area followed by a decline after canopy closure.However,neither the hypothesis of constant leaf area nor the hypothesis of a maximum leaf area clearly explained why leaf area should remain constant or decline after canopy closure from the growth models.In this study,data were collected from 54 plots,containing 144 trees in various subtropical climatic zones.We developed tree leaf area and stand density models for Chinese fir using nonlinear mixed-effects models based on six growth equations(Richards,Logistic,Gompertz,Mitscherlich,Korf,Weibull).The stand leaf area was determined by multiplying the tree leaf area by the number of trees.Then we explored the dynamic change of stand leaf area.The results showed that the optimal tree leaf area model(at the plot level) considered the random effect of the plot on the parameter ‘a' of the Logistic function.The optimal stand density model(at the population-averaged level) considered the random effect of the site on the parameter ‘a' of the Logistic function.However,the heteroscedasticity structure of both models was not considered.The dynamic change in stand leaf area followed a unimodal pattern,increasing rapidly during the young growth phase,peaking,and then gradually declining at a slower rate.With the consideration of self-thinning as a premise,from the growth model perspective,the dynamic change in stand leaf area exhibited a unimodal pattern,instead of remaining constant after reaching its peak.In addition,the decrease of

关 键 词：杉木 林分叶面积 动态变化 单峰 自然稀疏 

分 类 号：S791.27[农业科学—林木遗传育种]