2006-2010年下辽河平原地温和土壤热通量变化特征

依据国家沈阳农田生态系统野外研究站2006-2010年监测数据，分析0-100cm 土层8个层次的地温、0-100 cm地温、地温极值、0-20 cm地温与气温的关系和土壤热通量的变化趋势。结果表明：从年际变化看，8个层次地温和地温极值呈下降趋势；0 cm层次地温变化受外界影响较大。研究区域年尺度0-20 cm地温与气温有比较一致的变化规律。作物生长季节，可分为4-7月气温上升和8-10月气温下降两阶段；这两个不同阶段的0-20 cm地温与气温分别做线性拟合，与整个生长季4-10月线性拟合相比，线性相关性可信度更高。土壤热通量受气温和土壤质量含水量影响年际变化较大，年尺度土壤热通量≥0 MJ/m²，该区域地表是热汇。

Characteristics of soil temperature and soil heat flux from 2006 to 2010 in the lower reach of the Liaohe River plain

Based on the monitoring data from the national agroecosystems field research station in Shenyang from 2006 to 2010,the soil temperature from 0 cm to 100 cm soil layer was divided into 8 layers(0 cm,5 cm,10 cm,15 cm,20 cm,40 cm,60 cm and 100 cm)and the characteristics of each soil layer were analyzed.The relationships between soil temperature in 0-100 cm soil layer and its extreme value,soil temperature in 0-20 cm soil layer,and air temperature were discussed.At same time,the trends of soil heat flux were analyzed.The results indicate that for inter-annual variation,the soil temperature in 8 soil layers and its extreme value are in the decreasing trends.Soil temperature on 0 cm soil layer is largely influenced by the outside environment.The trends of soil temperature in 0-20 cm soil layer and air temperature are consistent at annual scale in the study area.Air temperature during the growth season could be divided into two stages,i.e.the ascending stage from April to July and the descending stage from August to October.The linear fitness between soil temperature in 0-20 cm soil layer and air temperature is respectively carried out in two stages,and it is compared with the linear fitness during the growth season from April to October.The linear correlation is significant.The inter-annual variations of soil heat flux are large because of the influence of air temperature and soil water content.Soil heat flux exceeds 0 MJ · m-2 on the annual scale,so soil surface is the heat sink in the study area.