贡嘎山不同海拔森林土壤热通量垂直梯带时空变异特征  

Spatial and Temporal Patternsof Soil Heat Flux in Forest at Different Elevations in Gongga Mountain

作　　者：杨阳[1] 王根绪[1] 孙向阳[1] 胡兆永 周云波 Yang Yang;Wang Genxu;Sun Xiangyang;Hu Zhaoyong;Zhou Yunbo(Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,P.R.China;Surveying and Mapping Technology Service Center,Sichuan Bureau,Surveying,Mapping and Geoinformation)

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,成都610041 [2]四川测绘地理信息局测绘技术服务中心

出　　处：《东北林业大学学报》2021年第8期70-77,共8页Journal of Northeast Forestry University

基　　金：国家自然科学基金重大项目(41790431),中国科学院战略性先导科技专项(A类)(XDA23090201)。

摘　　要：基于贡嘎山垂直植被带谱3种典型森林(阔叶林、针阔混交林、针叶林)土壤热通量的连续观测,分析了土壤热通量的时空变异规律及其影响因子。结果表明:月尺度上,阔叶林土壤热通量在3—8月、针阔混交林、针叶林在4—8月以向下传输为主,其他月份为向上传输为主;阔叶林、针阔混交林和针叶林年总土壤热通量分别为-1.88、-13.78和-9.61 MJ·m^(-2),占年净辐射的百分比分别为0.07%、0.47%、0.35%,说明年尺度土壤热通量并未达到平衡。土壤热通量对净辐射存在迟滞效应,阔叶林和针阔混交林反馈要迟滞3 h,针叶林为6 h。3种森林类型土壤热通量占净辐射比例随叶面积指数增大而减小。净辐射、2 m气温、5 cm土壤温度、10 cm土壤温度和叶面积指数共同影响着土壤热通量的季节变化。在阔叶林和针阔混交林中,净辐射相对贡献率最高(34.54%,30.12%);在针叶林中,叶面积指数贡献率最高(27.47%)。阔叶林、针阔混交林和针叶林土壤热通量没有表现出明显的海拔梯度规律,但阔叶林土壤热通量与针阔混交林和针叶林差异显著。土壤热通量表现出明显的差异性,主要是受到植被和气候因子共同影响。The spatiotemporal variation of soil heat flux in vertical vegetation zone plays an important role in land-air coupled Model for mountain ecosystems,which provides basic theoretical support for the establishment and testing of ecological and climate models.With the continuous observational datain the Hailuogou Valley of Gongga Mountain,the spatial-temporal patterns of soil heat fluxes in the broad-leaved forests(BLF),coniferous and broad-leaved mixed forests(CBF),and coniferous forests(CF)were analyzed.The soil heat fluxes transmit downward from March to August in BLF and from April to August at CBF,and CF,while transmit upward in other months.The total soil heat fluxes are-1.88,-13.78 and-9.61 MJ·m^(-2) in BLF,CBF and CF,respectively.The proportions of soil heat fluxes to the net radiation are 0.07%,0.45%and 0.35%in BLF,CBF and CF,respectively,indicating that the soil heat fluxes are unbalanced in the three forests.There is time-lag effect in soil heat fluxes to net radiation,with 3-h time-lag in the BLF and CBF,and 6-h time-lag in the CF.The ratios of soil heat fluxes to the net radiation decrease with the increase of leaf area index.The net radiance,air temperature at 2-m high,soil temperature in 5-and 10-cm depth affect the seasonal variation of soil heat fluxes significantly.Specifically,the highest contribution is net radiation in BLF(34.54%)and CBF(30.12%),while leaf area index is in the CF(27.47%)to the seasonal variations of soil heat fluxes.Although the soil heat flux in the BLF is significantly different with those in CBF and CF,the soil heat fluxes don’t present obviously pattern along the altitudinal gradient.Soil heat flux shows obvious difference,mainly influenced by vegetation and climate factors.

关 键 词：土壤热通量 山地 森林 净辐射 叶面积指数 时空变异 

分 类 号：S152.5[农业科学—土壤学] S718.5[农业科学—农业基础科学]