植被对土壤热扩散特征的影响——以长白山阔叶红松林为例  

The influence of vegetation on soil thermal properties: a case study of broadleaved Korean pine forest in Changbai Mountain

作　　者：施婷婷[1] 郑兴波[2] 张丽波[1] 杨弘[2] 李辉东[2] 李伟莉[3] 高玉芳[1] 

机构地区：[1]南京信息工程大学,应用气象学院,生态气象环境研究中心,南京210044 [2]中国科学院沈阳应用生态研究所,沈阳110016 [3]沈阳市水利建筑勘测设计院,沈阳110015

出　　处：《生态学报》2015年第12期3970-3978,共9页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41105112;41105077);南京信息工程大学生态气象环境研究中心科研基金;江苏省自然科学基金面上项目(BK2012859);江苏高校优势学科建设工程(PAPD)

摘　　要：土壤温度变化及热传递是影响土壤和大气水热交换的重要过程,而植被是决定这种变化和影响的环境因子之一。通过比较林地与裸地土壤热特性的差异分析植被对土壤热扩散的影响。研究内容包括观测2007年长白山阔叶红松林区不同深度的土壤温度以及同期土壤含水量和叶面积指数。分析不同深度林地与裸地土壤温度年周期特征,根据热传导方程估算各土壤层温度的阻尼深度和热扩散率,并探讨引起林地与裸地土壤热特性差异的可能原因。结果表明,林地与裸地的土壤温度有明显的时空变化规律。随着深度的增加,土壤温度年周期的振幅逐渐减小、相位逐渐增大、平均值逐渐升高。林地土壤温度年平均值低于裸地,表层年平均温度相差约0.8℃;地表以下相同深度处,林地土壤温度年周期的振幅约低于裸地2.6—2.9℃,相位约小于裸地0.2—0.24 rad(角速度),这表明林地土壤温度极大值和极小值出现的时间比裸地滞后约11—14d。土壤温度阻尼深度和热扩散率随深度的增加而逐渐增大,而在1.6—3.2m则略有降低的趋势。林地与裸地土壤温度和热特性的时空特征和差异可能与土壤含水量和叶面积指数有关。Vegetation is one of the determining factors for soil temperature variation and thermal transfer, which are important processes for the energy and water exchange on the land-atmosphere interface. This study was to understand the impacts of vegetation on soil thermal diffusivity through comparing observations on forested and bared lands. The observations were made in broadleaved Korean pine forest over Changbai Mountain during 2007. The annual cycle of soil temperature and thermal properties at five depths were measured, together with soil volumetric water content and leaf area index.. The soil thermal diffusivity and damping depth of the soil temperature fluctuations were estimated using the heat conduction equation and the sinusoidal-fluctuating temperature at the ground surface. The potential environmental factors for the thermal properties were explored. The results show that soil temperature in both bared land and forest had similar spatial and temporal variations but with different magnitudes. With increasing soil depth, the amplitude of annual temperature variation decreased gradually, while both its phase and annual average temperature itself increased. In comparison with the based soil, the annual average temperature of the surface soil layer in the forest was 0.8℃ lower, the annual amplitude of soil temperature was 2.6-2.9℃ lower, and the temperature phase was 0.2-0.24 rad lower, suggesting that the maximum and minimum temperatures of the forest lagged by 11-14 days behind those of the bare land. The damping depth and thermal diffusivity increased with the soil depth, with an exception for the 1.6-3.2m layers where slightly decrease with depth was observed. It is indicated that soil moisture and leaf area index are probably responsible for the different characteristics in soil temperature and thermal properties between the forest and bared land.

关 键 词：土壤温度 热扩散 阔叶红松林 阻尼深度 

分 类 号：S714[农业科学—林学]