樟树人工林小气候特征研究

Microclimate Characteristic of Cinnamomum camphor Plantation

为了探讨樟树人工林形成的环境基础和森林对气候环境的影响，在樟树人工林建立气象站进行小气候长期定位观测研究。结果表明，樟树人工林的气温、湿度、土壤温湿度等表现出与太阳辐射趋势相同但不完全一致的变化规律，在晴天全光照条件下，林冠边界层叶面气温日变化呈现与太阳辐射相同的单峰变化趋势，但最高温度出现的时间一般比太阳辐射的峰值迟滞3-4h左右；相对湿度的日动态全年呈“U”型变化，但不同生长季节的湿度最高值、最低值和变化幅度有差异，林冠中部的空气相对湿度均高于林冠下；土壤温度由于温度变化迟滞效应，日变化和季节变化与太阳辐射或气温变化不同步，土壤湿度日变化和季节变化较小，在全年中，叶初期土壤含水率最高，叶盛期最低，叶衰期较高，表明土壤水分受植物生长影响大。

In order to explore the eveironmental conditions for the formation of Cinnamomurn camphor plantation and the influence on climate and environment by forests, a monitoring station was set up in the plantation . The results showed that although the fluctuations of the atmosphere temperature, humidity, soil temperature,soil humidity,etc, of the C. camphor plantation were not in well accordance with that of sun radiation, the single-top shaped diurnal variations curve of the temperature of leaves around the canopy edge fitted quite well with sun radiation. The highest temperature occurred 3-4 hours after the climax of sun radiation ; the annual dynamic curve of the relative humidity was ＂U＂ shape. But differences existed in the highest ,lowest and amplitude of the humidity among years. The relative humidity in middle canopy was higher than upper canopy ; because of the delayed effect of temperature,the diurnal and seasonal variations of the soil temperature were not synchronize with sun radiation or atmosphere temperature. The diurnal and seasonal variations of the soil humidity were smaller. During the whole year, the moisture rate of soil decreased from the initial stage of leaves to the flourishing stage of leaves but increased in the declining stage of leaves which was still lower than the initial stage of leaves ,this indicated that the growth of plant was greatly influenced by soilwater.