桂西南北热带喀斯特季节性雨林土壤钾、钙、镁空间分布特征及其影响因素  

Spatial distribution characteristics of soil potassium,calcium,and magnesium and their influencing factors in a northern tropical karst seasonal rainforest in southwestern Guangxi

作　　者：李佳奇 郭屹立[1,2] 李冬兴 王斌[1,2] 向悟生 黄甫昭[1,2] 陆芳 文淑均[1,2] 李健星 陆树华[1,2] 李先琨 Jiaqi Li;Yili Guo;Dongxing Li;Bin Wang;Wusheng Xiang;Fuzhao Huang;Fang Lu;Shujun Wen;Jianxing Li;Shuhua Lu;Xiankun Li(Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain,Guangxi Institute of Botany,Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences,Guilin,Guangxi 541006;Nonggang Karst Ecosystem Observation and Research Station of Guangxi,Chongzuo,Guangxi 532499;College of Tourism and Landscape Architecture,Guilin University of Technology,Guilin,Guangxi 541006)

机构地区：[1]广西壮族自治区中国科学院广西植物研究所广西喀斯特植物保育与恢复生态重点实验室,广西桂林541006 [2]弄岗喀斯特生态系统广西野外科学观测研究站,广西崇左532499 [3]桂林理工大学旅游与风景园林学院,广西桂林541006

出　　处：《生物多样性》2023年第2期174-185,共12页Biodiversity Science

基　　金：国家自然科学基金(32071540,32260286);广西自然科学基金(2022GXNSFDA035076,2022GXNSFBA035552)。

摘　　要：矿质元素是土壤养分的重要组分,关系着森林生态系统的群落组成和生物地球化学循环。喀斯特局域尺度内地形异质性较高,目前尚缺乏地形等非生物因子和生物因子如何影响喀斯特地区土壤矿质元素空间分布方面的研究。本文在弄岗北热带喀斯特季节性雨林15 ha森林动态监测样地中沿海拔梯度设立的100个凋落物收集器所在位点进行土壤取样,对样品中的K、Ca、Mg 3种矿质元素含量进行测定,并基于空间回归模型和变差分解等方法对喀斯特季节性雨林中土壤K、Ca、Mg与生态因子之间的关联进行定量分析,探讨非生物因子和生物因子与其空间分布特征的内在关联,以期为北热带喀斯特生物地球化学循环研究和脆弱喀斯特生态系统保护提供科学依据。结果表明,研究区内土壤K、Ca、Mg均存在空间自相关性,Ca与海拔和凹凸度显著正相关,主要聚集在山脊区域;K与地形湿润度指数显著正相关,主要在洼地聚集;Mg在中坡位表现出聚集特征。变差分解显示生态因子对土壤K、Ca、Mg空间分布的驱动作用强于空间结构,单个生态因子中海拔的解释度最高,并且非生物因子的解释度总体上高于生物因子,生物因子中物种丰富度解释度最高,同时Mg的聚集伴随着较高的物种丰富度水平。Aims:Mineral elements are important determinants of soil nutrients and are related to forest community composition and nutrient cycling.There is high terrain heterogeneity in karst seasonal rainforest local scale,but there is still lack of research on how terrain and other abiotic and biotic factors affect the spatial distribution of soil mineral elements in karst area.Methods:In this study,we set up 100 litter fall traps along the elevation gradient in the 15 ha northern tropical karst seasonal rainforest dynamics plot in Nonggang,southwestern Guangxi,and conducted soil sampling at the litter fall trap sites.We tested soil samples for the content of mineral elements such as K,Ca,Mg.We performed quantitative analysis of the association between ecological factors and soil K,Ca,Mg in karst seasonal rainforests based on methods such as spatial regression models and variation partitioning.Results:Soil K,Ca and Mg in the study area were all spatially autocorrelated,with Ca significantly positively correlated with elevation and convexity(P<0.05),mainly clustered in the hilltop;K significantly positively correlated with topographic wetness index,mainly clustered in low-lying land;Mg showed clustering characteristics in the hillside.Variation partitioning shows that ecological factors drove the spatial distribution of soil K,Ca and Mg more than spatial structure.Elevation was the highest predictor variable among the individual ecological factors,and abiotic factors were higher than biotic factors in general,and species richness was the highest among biotic factors,while the aggregation of Mg elements was accompanied by a higher level of species richness.Conclusion:In this study,the soil K,Ca and Mg in the 15 ha northern tropical karst seasonal rainforest dynamics plot in Nonggang have spatial autocorrelation,and the spatial distribution of the three soil elements was significantly different.In the karst seasonal rainforest in southwestern Guangxi,ecological factors such as altitude have a strong driving effect on the spa

关 键 词：土壤矿质元素 生态因子 空间回归模型 变差分解 北热带喀斯特季节性雨林 

分 类 号：S714.2[农业科学—林学]