Stable reverse J-shaped diameter distribution occurs in an old-growth karst forest  

作　　者：Yuanfa Li Jie Li Liting Wei 

机构地区：[1]Guangxi Key Laboratory of Forest Ecology and Conservation,Guangxi Colleges and Universities Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantation,College of Forestry,Guangxi University,Nanning 530004,People’s Republic of China [2]Laibin Jinxiu Dayaoshan Forest Ecosystem Observation and Research Station of Guangxi,Laibin 545700,People’s Republic of China

出　　处：《Journal of Forestry Research》2024年第6期135-147,共13页林业研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(32060340 and 31400542);the Scientific Research Capacity Building Project for Laibin Jinxiu Dayaoshan Forest Ecosystem Observation and Research Station of Guangxi(22-035-130-01).

摘　　要：The reverse J-shaped diameter distribution is considered an inherent attribute of natural forests,cru-cial for forest resource utilization and community stability.However,in karst regions,intense habitat heterogeneity might alter species composition,spatial distribution,growth,biomass allocation,and mortality processes,yet its impact on diameter structure remains unclear.A fixed plot of 200 m×110 m was established in the Nanpan River Basin,Southwest China,within an old-growth oak forest(>300 years old),and the influence of site substrates(i.e.,rock and soil),topographic factors,sample area,and orientation on diameter distribution was analyzed.Trees on both rock and soil exhibited a reverse-J shape,quantifiable Project funding:This work was supported by the National Natural Science Foundation of China(32060340 and 31400542),the Scientific Research Capacity Building Project for Laibin Jinxiu Dayaoshan Forest Ecosystem Observation and Research Station of Guangxi(22-035-130-01).through the Weibull function.The substrates had a similar density,approximately 2100 plants/ha.However,the average and range of diameter of trees on rock were smaller than those on soil,suggesting that rock constrains tree growth.The diameter distribution of trees across microtopography also displayed a reverse-J shape.Yet,higher elevations and sunny slopes showed a greater curvature of diameter classes compared to lower elevations and shady slopes,indicating habitat preferences in karst trees.Sample area and orientation had minimal effects on diameter class curve that reached stability when the plot size was 6000 m2.These results suggest that the reverse J-shaped diameter distribution prevails at small scales in karst old-growth forests,encompassing multiple curvatures and spanning forest ecosystems.

关 键 词：Old-growth forest Diameter distribution KARST Habitat heterogeneity MICROTOPOGRAPHY 

分 类 号：S718.5[农业科学—林学]