摘要
为研究木本植物自然恢复过程中生态系统碳密度对群落结构变化的响应机制,选取百山祖国家公园高、中、低3种杉木萌条保留密度(1154、847和465株·hm^(-2))下自然恢复初期林分为研究对象,分析生态系统碳密度及其组分与树种多样性、林分结构多样性(胸径变异系数)、林分空间结构参数(混交度、角尺度、大小比数、密集度)之间的关系。结果表明:随杉木萌条保留密度减少,树种多样性(物种丰富度指数、Shan⁃non多样性指数)增加;林分结构参数中胸径变异系数、林分密度和混交度随杉木萌条保留密度减少呈升高趋势,不同杉木保留密度处理林分分布格局均为均匀分布,林木生长状态均为亚优势,林分密集程度均为比较密集。高、中、低3种杉木萌条保留密度处理乔木层碳密度分别为57.56、56.12和46.54 t·hm^(-2),土壤层碳密度分别为104.35、122.71和142.00 t·hm^(-2),生态系统碳密度分别为164.59、182.41和190.13 t·hm^(-2),林下植被层和凋落物层碳密度在不同处理之间变异较小。不同杉木保留密度处理生态系统碳密度分配特征均为土壤层(63.4%~74.7%)>乔木层(24.5%~35.0%)>林下植被层与凋落物层(0.8%~2.0%)。方差分解结果表明,乔木层碳密度变化主要受林分结构多样性影响,土壤层碳密度受树种和结构多样性共同影响,而生态系统碳密度主要受树种多样性影响,林分空间结构参数对生态系统碳密度及其组分影响相对较小。在试验区杉木人工林向天然林转变过程中,杉木萌条保留密度显著影响生态系统碳积累,保留较低的杉木密度(500株·hm^(-2)左右)更有利于林分固碳增汇。
To explore potential responses of ecosystem carbon density to changes of community structure during natural regeneration of woody plants,we analyzed the relationships between ecosystem carbon density and its com⁃ponents,tree species diversity,structural diversity(CVDBH)and spatial structure parameters(mingling,aggrega⁃tion,dominance,crowding)of Cunninghamia lanceolata forests with different sprouting densities(1154,847 and 465 individuals·hm^(-2))at the early stage of succession in Baishanzu National Park.The results showed that tree species diversity(species richness index and Shannon diversity index)increased with the decrease of sprouting density of C.lanceolata.Among the stand structural parameters,CVDBH,stand density,and mingling increased with the decrease of sprouting density of C.lanceolata.The stand distribution pattern of different C.lanceolata densities was uniform,with sub⁃dominant stand growth status and relatively dense status.The carbon density of tree layer under high,medium,and low sprouting densities of C.lanceolata were 57.56,56.12 and 46.54 t·hm^(-2),soil car⁃bon density were 104.35,122.71 and 142.00 t·hm^(-2),and the total carbon density of ecosystem were 164.59,182.41 and 190.13 t·hm^(-2),respectively.There was little variation in carbon density of understory layer and litter layer among different treatments.The carbon density distribution characteristics of different C.lanceolata densities were following the order of soil layer(63.4%-74.7%)>tree layer(24.5%-35.0%)>understory layer and litter layer(0.8%-2.0%).The results of variance partitioning analysis indicated that the change of tree layer carbon density was mainly influenced by stand structure diversity,soil layer carbon density was influenced by both tree spe⁃cies diversity and stand structure diversity,while ecosystem carbon density was mainly influenced by tree species diversity.Stand spatial structure parameters had a relatively little effect on ecosystem carbon density and its compo⁃nents.The sprouting density of C.lanceolata significantly affected ecosystem carbon accumulation during the con⁃version from C.lanceolata plantations to natural forests.A lower remaining density of C.lanceolata(about 500 indi⁃viduals·hm^(-2))was more conducive to forest carbon sequestration.
作者
张煜林
刘玲娟
刘胜龙
方万力
骆珍莎
洪宣生
成向荣
ZHANG Yulin;LIU Lingjuan;LIU Shenglong;FANG Wanli;LUO Zhensha;HONG Xuansheng;CHENG Xiangrong(Research Institute of Subtropical Forestry,Chinese Academy of Forestry,Hangzhou 311400,China;Nanjing Forestry University,Nanjing 210037,China;Longquan Conservation Center of Qianjiangyuan-Baishanzu National Park,Longquan 323700,Zhejiang,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2024年第2期289-297,共9页
Chinese Journal of Applied Ecology
基金
百山祖国家公园科学研究项目(2021KFLY02)资助。
关键词
树种多样性
林分结构
碳密度
自然恢复
杉木
tree species diversity
stand structure
carbon density
natural restoration
Cunninghamia lanceolata
