森林与空旷地空气温湿度及土壤温度的长期对比研究

A long-term observation on the air temperature,relative humidity,and soil temperature in a mixed forest and its adjacent open site in Changbai Mountains of Northeast China

森林对温湿度的影响是其生态功能的基础,为了探讨森林的这种小气候效应,本文采用小气候对比观测的方法,根据2005—2007年观测资料,对长白山阔叶红松林与附近空旷地温度、湿度等小气候要素进行了差异性研究。结果表明,林内近地表层空气温度白天低于林外空旷地,晚间高于林外空旷地,因而具有较低的日较差。非生长季二者的月平均值差异不显著,但生长季差异明显,月平均气温最高差值出现季节与森林叶面积指数最大值出现时间一致。气温年较差的平均值林内小于空旷地,差值可达6.3℃。年均森林与空旷地土壤温度全年均表现出明显差异,以0℃为界,0℃以上,林内土壤温度低于空旷地,0℃以下高于空旷地,其中2005年1月5cm深处土壤温度差值达到了5.3℃。空气相对湿度生长季差异较大,其中以7、8月份差异最为明显,2006年7月差值最大,达7.0%。

The influence of forest on air temperature and relative humidity is the basis of forest ecological function.Aimed to approach the microclimatic effect of forest,a three-year（2005-2007） micrometeorological observation was conducted on the diurnal and seasonal changes of air temperature and relative humidity in a broadleaved-Korean pine mixed forest and its adjacent open site in Changbai Mountains,Northeast China.As compared with open site,the air temperature in the near-ground surface in the forest was lower at daytime but higher at night,with a lower diurnal difference.There was a remarkable difference in the mean monthly air temperature in the near-ground surface between the forest and open site in growth season,but no obvious difference in non-growth season.The greatest difference appeared in July,which coincided with the appearance of the maximal leaf area index of the forest.The mean annual air temperature difference was lower in the forest than in open site,with a difference up to 6.3 ℃.There also existed a remarkable difference in the soil temperature between the forest and open site.Throughout the observation years,the forest had a lower soil temperature than the open site when the soil temperature was above 0 ℃,but was in adverse when the soil temperature was below 0 ℃,with the difference of mean monthly soil temperature at 5 cm depth between forest and open site up to 5.3 ℃ in January,2005.In growth season,the relative humidity in the forest and open site had a significant difference,especially during the peak growth season July-August,with the greatest difference up to 7.0 ℃ in July,2006.