【摘要】 为进一步研究黄河三角洲盐碱地区土壤-植被-大气连续体的作用机理并为热量平衡研究提供基础数据,本试验以黄河三角洲盐碱地区长期生长的刺槐人工林为对象,利用黄河三角洲森林生态系统定位研究站2016年度观测数据,研究了该地区刺槐人工林土壤热通量的变化特征及其与地表净辐射的关系。结果表明:10、20 cm土层土壤热通量日变化基本呈现"S"型变化,且随土壤深度增加振幅减小;两层土壤热通量的月累积总量在3—8月为正值,其它月份为负值;两层的年总土壤热通量分别为-23. 85、-12. 97 MJ/m~2,占地表净辐射(720. 07 MJ/m~2)的比例分别为-3. 31%、-1. 80%,土壤均表现为热源;在日尺度、月尺度水平上,土壤热通量与地表净辐射分别呈极显著和显著正相关;土壤热通量对地表净辐射的反馈存在延时效应,延时5 h的10 cm土层土壤热通量和延时9 h的20 cm土层土壤热通量与地表净辐射相关性最高。本研究得出土壤热通量与地表净辐射关系密切,这对研究土壤-植被-大气连续体中地气能量交换和热量平衡具有重要意义。更多还原

【Abstract】 In order to further study the action mechanism of soil-plant-atmosphere continuum and provide basic data for studying the heat balance in the Yellow River Delta of saline-alkali area,based on the2016 annual data of forest ecosystem positioning research station of the Yellow River Delta,the long-term plantation of Robinia pseudoacacia was taken as research objects to study the variation characteristics of soil heat flux and its relationship with surface net radiation. The results suggested that the diurnal variations of soil heat flux at 10-and 20-cm depth mostly showed S shapes,and the amplitude decreased with the depth of soil layers. The monthly accumulation of soil heat fluxes of both layers was positive from March to August and negative in the other months. The annual total soil heat fluxes at 10-cm and 20-cm depth were-23. 85 and-12. 97 MJ/m~2 respectively with the proportion of total soil heat fluxes to the surface net radiation( 720. 07 MJ/m~2) as-3. 31% and-1. 80% respectively,indicating that the soil of both layers was heat source at the annual temporal scale. There were extremely significant correlations between soil heat fluxes and the surface net radiation at daily temporal scale,while significant correlations at monthly temporal scale. There was time-lag effect in the feedback of soil heat flux to surface net radiation,the soil heat fluxes lagged 5 h at10-cm depth and 9 h at 20-cm depth had the most correlation with the surface net radiation. In this study,we concluded that the soil heat flux was in close relationship with the surface net radiation,which had great significance to studying the energy exchange between ground and atmosphere among soil-plant-atmosphere continuum and heat balance.更多还原