天山西部山地森林土壤有机碳沿海拔的分布格局及环境驱动因素  

Vertical distribution patterns of soil organic carbon along elevational gradients and its environmental drivers in the montane forests of the western Tianshan Mountains,China

作　　者：吴芳 孙慧兰[1] 田中平 叶茂[1] 刘天弋 杨涵[1] 金晓亮 WU Fang;SUN Huilan;TIAN Zhongping;YE Mao;LIU Tianyi;YANG Han;JIN Xiaoliang(College of Geographical Sciences and Tourism,Xinjiang Normal University,Urumqi 830054,China;College of Life Sciences,Xinjiang Normal University,Urumqi 830054,China)

机构地区：[1]新疆师范大学地理科学与旅游学院,乌鲁木齐830054 [2]新疆师范大学生命科学学院,乌鲁木齐830054

出　　处：《应用与环境生物学报》2024年第4期715-725,共11页Chinese Journal of Applied and Environmental Biology

基　　金：第三次新疆综合科学考察专题(2021xjkk0406);新疆师范大学青年拔尖人才项目(XJNUQB2023-11)资助。

摘　　要：森林土壤有机碳(SOC)库对于维持生态系统碳平衡具有重要意义.然而,关于天山西部山地森林SOC垂直变化规律及其影响因素的解释仍然存在争议.在天山西部山地沿两条海拔梯度建立固定样地,实时监测微气候,结合GIS技术提取平面曲率(FC)、剖面曲率(PC)、地形起伏度(TR)、地表粗糙度(SR)和归一化植被指数(NDVI)等环境变量,采用地理加权回归模型(GWR)模拟森林SOC的空间分布特征,解析SOC海拔格局的驱动因素.结果表明:(1)天山西部森林土壤表层(0-20 cm)SOC平均含量(64.65-123.3 g/kg)远高于全国森林(42.4 g/kg)及中纬度其他山地生态系统(20.61-83.72 g/kg).(2)该地区森林SOS含量随海拔升高表现为单峰型分布(西天山)或随海拔升高呈现线性增长(野核桃沟),并没有形成统一的分布格局.(3)GWR模型分析指出,在西天山,环境垂直变化明显,土壤营养元素与微气候对SOC的空间分布起着更加重要的作用,主要影响因子为全钾(TK)、土壤pH、铵态氮(NH4-N)和土壤年均温(SMAT);相较之下,野核桃沟海拔高差较小,土壤营养元素对SOC分布的影响更强,尤其是全氮(TN)、硝态氮(NO_(3)-N)、pH值和TK.总体而言,天山西部森林SOC含量丰富,其分布主要受土壤营养元素与微气候综合影响,加之两个山地海拔跨度不同,导致环境垂直梯度的差异性影响,从而形成SOC沿海拔梯度变化的不同分布格局.该区SOC分布特征研究结果为森林的利用与管理提供了数据支持.(图6表5参70)The organic carbon pool in forest soils plays a crucial role in maintaining ecosystem carbon balance.However,the vertical variation patterns of soil organic carbon(SOC)and its influencing factors in western Tianshan Mountain forests remain controversial.This study aimed to discern the elevational distribution pattern of forest SOC and identify the predominant factors that influence this pattern.Furthermore,we sought to quantify the spatial correlation between the SOC and these factors.This study aims to provide a better basis for regional forest conservation and management.In this study,fixed plots were established along two elevational gradients in the western Tianshan Mountains.Real-time microclimate monitoring coupled with GIS technology was employed to extract environmental variables,such as flat curvature(FC),profile curvature(PC),topographic relief(TR),surface roughness(SR),and normalized difference vegetation index(NDVI).A geographic weighted regression(GWR)model was utilized to simulate the spatial distribution characteristics of the SOC and to decipher the driving factors of the SOC spatial distribution.The results revealed that the surface layer(0-20 cm)SOC content in the western Tianshan mountain region was abundant(64.65-123.3 g/kg),exceeding that of other mid-latitude mountain ecosystems(20.61-83.72 g/kg)and the national average(42.4 g/kg).Along different altitudinal(ALT)gradients,the spatial distribution patterns of SOC varied inconsistently,with the western Tianshan and wild walnut gullies forming unimodal and linearly increasing spatial distribution patterns with elevation,respectively.Western Tianshan exhibited more pronounced vertical changes in the environment and vegetation,with SOC being influenced by complex factors.Soil nutrient content and microclimate factors play significant roles in the spatial distribution of SOC,which is primarily influenced by total potassium(TK),soil pH,ammonium nitrogen(NH4-N),and soil mean annual temperature(SMAT).Conversely,the Wild Walnut Gully,with a smaller al

关 键 词：森林 地理加权回归模型 土壤有机碳 空间分布 环境变量 

分 类 号：S714.2[农业科学—林学]