热带季节雨林林窗区域土壤-植物-大气连续体热力效应初步分析

利用西双版纳雾凉季和干热季热带季节雨林林窗的小气候观测资料,探讨了昼间林窗地表温、气温及下层植物的叶温的时空分布和变化规律,分析了叶温与气温和地表温的相互关系指出在林窗区域,由于受雾和太阳高度的影响,各小气候要素最大值随时间、季节的不同,出现在林窗不同的方位,并且存在叶温高值区时空动态位移现象;另外,林窗区域土壤-植物-大气连续体界面间热量传递方向随时间、季节的不同而发生着改变,甚至在同一时段内,林窗不同区域会存在热量传递方向截然相反的现象,显示出林窗内可能存在热量循环的小环流.其结果对深入探讨林窗区域的热量传输,小气候的形成机制、生物多样性和更新等问题均具有重要意义.

A Primary Study on Thermal Effect of Soil-Plant-Atmosphere Continuum in Tropical Seasonal Rain Forest Gap

Made use of measurement data of microclimatic elements of canopy gap in tropical seasonal rain forest in fog cool and dry hot season in Xishuangbanna, the daytime characteristics of temporal spatial distribution and variation of soil surface temperature, air temperature, and leaf temperature of understory plants in canopy gap were discussed. The finding showed that influenced by fog and solar altitude, the maximum value of microclimatic elements displayed at different site of gap in different time and season and there existed phenomenon about higher value area of leaf temperature dynamic displacement. In addition, the direction of heat transferring of soil plant atmosphere continuum varied with time and season, indeed at the same time, the different part of gap had the different heat transferring directions. The results would supply a research basis for further studying heat and water vapor transport, microclimatic formation, biodiversity and succession of canopy gap.