| 摘要: |
| 为阐明喀斯特森林地上生物量特征及驱动因素，本研究在贵州省茂兰自然保护区内选取海拔在650-700 m的青冈栎林样地为研究对象，采取地上生物量方程计算青冈栎林群落地上生物量和优势树种地上生物量，并利用线性回归分析，Pearson相关性分析及结构方程模型等方法，探究青冈栎林地上生物量特征及物种多样性、结构多样性、地表因素和土壤理化性质等因素对森林地上生物量的相对影响。结果表明:①青冈栎林平均地上生物量为125.96 t·hm-2，优势树种占据主要地上生物量，累积贡献为68.11%；优势树种中青冈栎（Cyclobalanopsis glauca）和轮叶木姜子（Litsea verticillata Hance）地上生物量占比高，分别为21.08%和19.26%，并且常绿树种地上生物量明显高于落叶树种。②回归分析显示，地上生物量仅与物种多样性指标的物种均匀度指数显著正相关（P<0.05），与多数结构多样性指标极显著正相关（P<0.001）。③相关分析显示，环境因素与地上生物量、结构多样性和物种多样性的相关性较强，其中土壤含水量、有机质和全氮（土壤理化性质）与地上生物量和结构多样性呈极显著正相关（P<0.001），岩石裸露率（地表因素）则呈极显著负相关（P<0.001），有机质与物种多样性呈显著正相关（P<0.05）。④土壤理化性质和地表因素对地上生物量的解释作用（总效应分别为0.67和0.57）高于结构多样性和物种多样性（总效应分别为0.48和0.15），主要通过影响结构多样性和物种多样性来促进地上生物量积累。此外，结构多样性对地上生物量有显著的直接促进作用，而物种多样性的促进作用较低。综上，青冈栎林地上生物量主要受树木结构多样性（胸径、树高）、土壤理化性质和地表环境因素综合调控。因此，科学改善群落的土壤环境和地表特征，增加群落结构复杂性有助于喀斯特森林生产力提高。 |
| 关键词: 喀斯特森林 地上生物量 土壤理化性质 地表因素 结构多样性 |
| DOI： |
| 投稿时间：2024-11-24修订日期：2025-01-06 |
| 基金项目:国家自然科学基金(31660107)；黔科合平台人才项目([2020]6010-2，[2017]5726-45) |
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| Characteristics and Driving Factors Influencing the Above-ground Biomass of Cyclobalanopsis glauca Forest in Maolan National Reserve |
|
He Qing, Long Cuiling, Liu Qi, YUAN Rongli, Li Juan
|
| (College of Geography and Environmental Sciences, Guizhou Normal University) |
| Abstract: |
| In order to understand the characteristics and ecological drivers of above-ground biomass of karst forest, a Cyclobalanopsis glauca forest community with an altitude of 650-700 m was selected as the research object in Maolan Nature Reserve, Guizhou Province. Allometric growth equation was used to calculate the above-ground biomass of woody plants of Cyclobalanopsis glauca forest. The relative effects of species diversity, structure diversity, ground factors and soil physical and chemical properties on forest above-ground biomass were analyzed by regression model, Pearson correlation analysis and Structural equation model. The results showed that: ①The average above-ground biomass of Cyclobalanopsis glauca forest was 125.96 t·hm-2, and the dominant tree species occupied 68.11% of community above-ground biomass. Cyclobalanopsis glauca and Litsea verticillata Hance specie had higher proportion of above-ground biomass, 21.08% and 19.26% respectively. ②Regression analysis showed that above-ground biomass had merely significant positive correlation with species evenness index (P<0.05), but above-ground biomass had significant positive correlation with most structural diversity index (P<0.001). ③Correlation analysis showed that environmental factors were strongly correlated with above-ground biomass, structural diversity and species diversity. Specifically, soil moisture content, soil organic matter content and soil total nitrogen content (soil physical and chemical properties) were significantly positively correlated with above-ground biomass and structural diversity (P<0.001), rock exposure rate (ground factor) was significantly negatively correlated with above-ground biomass and structural diversity (P<0.001). Soil organic matter content had significant positive correlation with species diversity (P<0.05). ④The explanatory effects of soil physical and chemical properties and ground factors on above-ground biomass (total effects respectively were 0.67 and 0.57) were higher than those of structural diversity and species diversity (total effects respectively were 0.48 and 0.15), which mainly promoted above-ground biomass through structural diversity and species diversity. In addition, structural diversity had a significant direct positive effect on above-ground biomass, while species diversity had a low positive effect. In conclusion, the above-ground biomass of Cyclobalanopsis glauca forest was mainly regulated by tree structural diversity (DBH, tree height), soil physicochemical properties and surface environmental factors. Therefore, the research suggested that scientifically improving the soil environment, ground characteristics of the community and increasing forest structure complexity were conducive to promote karst forest productivity. |
| Key words: Karst forest Above-ground biomass Soil physical and chemical properties Ground factors Structural diversity |
