桂西北喀斯特典型森林植被的小气候特征

Features of microclimate of typical Karst forest vegetation in northwestern Guangxi

森林小气候是森林生态效益研究的重要组成部分。采用常规气象观测方法，于2006—2010年在木论自然保护区典型森林内及其空旷地（林外）建立气象观测场，进行了主要气象要素的同步对比观测研究。结果表明：（1）森林内年平均太阳辐射能为107．8×10^4W／m^2，占林外的5．3％。（2）林内年平均气温及年较差依次为16．3℃和17．2℃，均比林外降低0.2℃。（3）林内0～20cm土层年平均温度为16．7—17．1℃，分别比林外同一土层降低0．9～2．0℃；年较差为12．7～15．8℃，分别比林外同一土层降低3．2～4．4℃。（4）林内年平均降雨量及林冠截留量分别为1275．7mm和415．6mm，分别占林外降雨量的75．4％和24．6％。（5）林内年平均蒸发量为293．3mm，占林外的57．9％。（6）林内年平均相对湿度为84％，比林外降低2％。木论喀斯特森林削减了到达林内的太阳辐射能、降低林内温度，使林内温度变化缓和，同时减少了林内降雨量，使林内蒸发量减少等具有良好的小气候效应，但对林内的增湿效果不明显。

Forest microclimate was the important part of forest ecological benefits. To conduct the study on major meteorological elements of synchronous contrast observation, the conventional meteorological observation method was used, the meteorological observation field was established in typical forest and on the open area （outside the forest） from 2006 to 2010 in Mulun Nature Reserve. The results showed that： （1）The average annual solar radiation in the forest was 107.8 × 10^4 W/m^2, accounting for 5.3% of that outside the forest. （2） The annual average temperature in forest was 16.3℃ and the annual range was 17.2℃, which were 0.2℃ lower than that outside the forest, respectively. （3）The annual average temperature in the soil of 0-20 cm was 16.7-17.1℃, 0.9-2.0℃ lower than that outside the forest, and the annual range was 12.7-15.8℃, 3.2-4.4℃ lower than that outside the forest. （4） The average annual rainfall and the forest canopy interception were 1275.7 mm and 415.6 mm respectively, accounting for 75.4% and 24.6% of that outside the forest respectively. （5）annual average evaporation in forest was 293.3 mm, accounting for 57.9% of that outside the forest. （6）The annual average relative humidity in forest was 84%, 2% lower than that outside the forest. The results fully demonstrated that the Karst forests in Mulun have great micro-climate effects on reducing solar radiation energy, lowering forest temperature, making the temperature in forest mitigative, and reducing forest rainfall and forest evaporation, however, no markeed effect of increase of humidity in forest was observed.