文献类型：期刊文献

中文题名：杉木-闽楠近自然改造下杉木大径材出材量的影响因子

英文题名：Influencing factors of large-diameter timber yield of Cunninghamia lanceolata under the close-to-nature silviculture stands mixed with Phoebe bournei

作者：江怡航[1,2] 刘振华[3] 张建国[1] 张雄清[1,2]

第一作者：江怡航

机构：[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;[3]湖南林业科学院,长沙410000

年份：2025

卷号：36

期号：10

起止页码：3026-3032

中文期刊名：应用生态学报

外文期刊名：Chinese Journal of Applied Ecology

收录：;北大核心:【北大核心2023】；

基金：十四五国家重点研发计划课题(2021YFD2201304)资助。

语种：中文

中文关键词：杉木;大径材出材量;结构方程模型;空间结构;林下植被;近自然改造

外文关键词：Cunninghamia lanceolata;large-diameter timber;structural equation model;spatial structure;understory vegetation;close-to-nature silviculture

分类号：S791.27;S792.24

摘要：杉木是我国南方人工林的主要用材树种,提升其大径材出材量对实现人工林高质量发展至关重要。本研究以湖南省临武县不同杉木-闽楠混交比例的近自然改造林为对象,构建结构方程模型,解析林分生长、空间结构与林下植被多样性对杉木大径材出材量的影响机制。结果表明:模型拟合良好(R^(2)=0.729)。杉木胸径是影响大径材出材量的关键直接因子(路径系数=0.82,P<0.001),冠幅(路径系数=0.36,P<0.05)和适度的竞争强度(以Hegyi竞争指数表征,路径系数=0.33)亦具有正向作用。杉木保留密度(路径系数=-1.19,P<0.001)、树高结构异质性(以基尼系数表征,路径系数=-0.45)及灌木层多样性(Simpson指数,路径系数=-0.34,P<0.05)主要通过抑制杉木胸径生长间接降低大径材出材量。草本层多样性与草本生物量(路径系数均为0.16)则表现出正向的间接效应。因此,调控杉木保留密度与空间结构(如降低杉木密度、减小保留木大小比数等)、促进保留木径向生长,并维持合理的林下植被结构(如适度发展草本层、控制灌木层),是提升杉木-闽楠近自然改造林分中杉木大径材出材量的关键路径。
Cunninghamia lanceolata is the primary timber species in artificial forests in southern China.Increasing the large-diameter timber yield of this species is crucial for achieving high-quality development of artificial forests.We focused on close-to-nature stands of C.lanceolata-Phoebe bournei mixed forests with varying mixing ratios in Linwu County,Hunan Province,and constructed a structural equation model to analyze the mechanisms by which stand growth,spatial structure,and understory vegetation diversity influencing the yield of large-diameter timber.The results showed that the model exhibited a good fit(R^(2)=0.729).Diameter at breast height of C.lanceolata was the key direct factor affecting the yield of large-diameter timber(path coefficient=0.82,P<0.001),and crown width(path coefficient=0.36,P<0.05)and moderate competition intensity(represented by Hegyi competition index,path coefficient=0.33)had positive effects.In contrast,retained density of C.lanceolata(path coefficient=-1.19,P<0.001),tree height structure heterogeneity(represented by Gini coefficient,path coefficient=-0.45),and shrub layer diversity(Simpson index,path coefficient=-0.34,P<0.05)indirectly reduced the large-diameter timber yield by limiting the increases of diameter at breast height.The diversity and biomass of the herbaceous layer(path coefficient=0.16)exhibited positive indirect effects.In conclusion,regulating retained density and spatial structure of C.lanceolata(e.g.,reducing density and size ratio),promoting radial growth of retained trees,and maintaining a balanced understory composition(e.g.,promoting herb layer development and controlling shrub layer)are key strategies for enhancing the yield of large-diameter C.lanceolata timber in close-to-nature stands of C.lanceolata-P.bournei mixed plantations.