喀斯特常绿落叶阔叶混交林凋落叶养分含量时空分布特征  

Spatiotemporal distribution characteristics of leaf⁃litter nutrients in a karst evergreen and deciduous broad⁃leaved mixed forest

作　　者：淦江 黄国勤[2] 杜虎[1,3,4] 宋同清 曾馥平[1,3,4] 张立进 彭晚霞[1,3,4] 谭卫宁 黄静 GAN Jiang;HUANG Guoqin;DU Hu;SONG Tongqing;ZENG Fuping;ZHANG Lijin;PENG Wanxia;TAN Weining;HUANG Jing(Key Laboratory of Agro-ecological Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academic of Sciences,Changsha 410125,China;Center for Ecological Science,Jiangxi Agricultural University,Nanchang 330045,China;Guangxi Key Laboratory of Karst Ecological Processes and Services,Huanjiang Karst Ecosystem Observation and Research Station,Chinese Academy of Sciences,Huanjiang 547100,China;Guangxi Rock Desertification Control Industry Technology Research Institute,Nanning 530000,China;Management Center for Guangxi Mulun National Nature Reserve,Huanjiang 547100,China)

机构地区：[1]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [2]江西农业大学生态科学研究中心,南昌330045 [3]中国科学院环江喀斯特生态系统观测研究站广西喀斯特生态过程与服务重点实验室,环江547100 [4]广西石漠化治理产业技术研究院,南宁530000 [5]广西木论国家级自然保护区管理中心,环江547100

出　　处：《生态学报》2024年第2期733-744,共12页Acta Ecologica Sinica

基　　金：广西自然科学基金项目(2023GXNSFAA026109);国家自然科学基金项目(42071073);国家重点研发计划项目(2022YFF1300703);中国科学院青年创新促进会项目(2021366)。

摘　　要：森林生态系统中凋落物养分含量通常具有明显的时空异质性,为探究喀斯特常绿落叶阔叶混交林凋落叶养分含量的时空分布特征及其影响因素,以广西木论喀斯特常绿落叶阔叶混交林25hm2动态监测样地内151个凋落物收集器所收集的凋落叶为研究对象,选取连续12个月的凋落叶进行元素含量分析。结果显示:该森林群落凋落叶元素含量大小顺序为碳(C)>钙(Ca)>氮(N)>镁(Mg)>钾(K)>硫(S)>磷(P),分别介于471.85—496.33、20.27—28.29、17.34—23.10、2.79—5.49、1.80—4.38、1.82—2.22、0.96—1.21g/kg之间,呈现高Ca、Mg,低P、K的分布规律,并且随时间出现明显波动,其中C、N、P、S和Ca元素均在4月出现较大值,而K、Mg则在1月出现峰值。生物因子在5m和10m邻域范围内对凋落叶含量的影响基本一致,但10m尺度上地形因子和土壤因子对凋落叶元素含量的影响更为明显。10m邻域范围内生物和非生物因子对凋落叶P元素的随机森林累积解释率最高,达80.27%,C元素累积解释率最低,仅10.49%,其中海拔和坡度对凋落叶C、N、P、S、K、Ca和Mg含量均有强烈影响,岩石出露率和土壤铁(Fe)含量也会在一定程度上对凋落叶元素含量产生较大影响。综上所述,喀斯特常绿落叶阔叶混交林不同月际间凋落叶养分含量存在显著差异,10m尺度上海拔和坡度是凋落叶养分含量产生空间变异的主要原因。Litter nutrient content in forest ecosystems usually has significantly temporal and spatial heterogeneity.To explore the spatiotemporal distribution characteristics of leaf-litter nutrients and their influencing factors in karst evergreen and deciduous broad-leaved mixed forest,this paper took the litter collected by 151 litter collectors in 25 hectares dynamic monitoring plot of karst evergreen and deciduous broad-leaved mixed forest in Mulun,Guangxi.We selected the litter for 12 months to analyze their element content.The results showed that the order of element content in leaf litter was C>Ca>N>Mg>K>S>P,which were 471.85—496.33,20.27—28.29,17.34—23.10,2.79—5.49,1.80—4.38,1.82—2.22,and 0.96—1.21g/kg,respectively,showing a distribution pattern of high calcium and magnesium contents and low phosphorus and potassium contents.Among them,the contents of carbon,nitrogen,phosphorus,sulfur,and calcium all appeared large values in April,while potassium and magnesium appeared the maximum values in January.The effects of biological factors on leaf-litter content were basically same at the 5m and 10m neighborhood scales,but the effects of topographic and soil factors on the elemental content of leaf-litter were more pronounced at the 10m scale.Within a 10m neighborhood,the cumulative interpretation rate of phosphorus element was the highest,reaching 80.27%,while the cumulative interpretation rate of carbon element was the lowest with only 10.49%.Both altitude and slope had strong effects on the content of leaf-litter elements.The rock outcrop rate and iron content in the soil also greatly influenced the content of leaf-litter elements to a certain extent.In conclusion,there were significant differences in leaf-litter nutrient content between different months in karst evergreen and deciduous broad-leaved mixed forest,and elevation and slope at the 10m scale were the main causes of spatial variation in nutrient content of leaf-litter.

关 键 词：凋落物 养分 时空异质性 喀斯特 常绿落叶阔叶混交林 

分 类 号：S71[农业科学—林学]