Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China.
Nanjing Forestry University, Nanjing 210037, China.
Ying Yong Sheng Tai Xue Bao. 2024 Feb;35(2):289-297. doi: 10.13287/j.1001-9332.202402.014.
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 components, tree species diversity, structural diversity (CV) and spatial structure parameters (mingling, aggregation, dominance, crowding) of forests with different sprouting densities (1154, 847 and 465 individuals·hm) 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 . Among the stand structural parameters, CV, stand density, and mingling increased with the decrease of sprouting density of . The stand distribution pattern of different 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 were 57.56, 56.12 and 46.54 t·hm, soil carbon density were 104.35, 122.71 and 142.00 t·hm, and the total carbon density of ecosystem were 164.59, 182.41 and 190.13 t·hm, respectively. There was little variation in carbon density of understory layer and litter layer among different treatments. The carbon density distribution characteristics of different 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 species 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 components. The sprouting density of significantly affected ecosystem carbon accumulation during the conversion from plantations to natural forests. A lower remaining density of (about 500 individuals·hm) was more conducive to forest carbon sequestration.
为了探索在木本植物自然更新过程中群落结构变化对生态系统碳密度的潜在响应，我们分析了不同萌蘖密度（1154、847 和 465 株/hm）森林生态系统碳密度及其组成部分、物种多样性、结构多样性（变异性系数）和空间结构参数（混交度、聚集度、优势度、拥挤度）之间的关系。该研究以百山祖国家公园演替早期的森林为研究对象。结果表明，物种多样性（物种丰富度指数和 Shannon 多样性指数）随着萌蘖密度的降低而增加。在林分结构参数中，变异性系数、林分密度和混交度随着萌蘖密度的降低而增加。不同萌蘖密度的林分分布格局均匀，处于亚优势种生长状态，较为密集。高、中、低萌蘖密度的林分中，乔木层碳密度分别为 57.56、56.12 和 46.54 t·hm-2，土壤碳密度分别为 104.35、122.71 和 142.00 t·hm-2，生态系统总碳密度分别为 164.59、182.41 和 190.13 t·hm-2，林下植被层和凋落物层的碳密度变化不大。不同萌蘖密度下的土壤层（63.4%-74.7%）>乔木层（24.5%-35.0%）>林下植被层和凋落物层（0.8%-2.0%）。方差分解分析结果表明，乔木层碳密度的变化主要受林分结构多样性的影响，土壤层碳密度的变化同时受物种多样性和林分结构多样性的影响，而生态系统碳密度主要受物种多样性的影响。林分空间结构参数对生态系统碳密度及其组成的影响相对较小。萌蘖密度显著影响从人工林到天然林的转换过程中生态系统的碳积累。较低的萌蘖密度（约 500 株/hm）更有利于森林的碳封存。
