桉树人工林不同林冠高度小气候特征研究

对比分析了桉树人工林内不同高度位置的大气温度、空气湿度、水汽压、风速的变化特征,结果表明:林冠层以下日平均气温存在随高度增加而增加的辐射逆温现象;与林冠上方相比,空气相对湿度日均值雨季前(2—4月)较小,雨季(5月)以后较大,但变化幅度均较小;林冠层以下水汽压日均值较林冠上方大但变动幅度相对较小;林冠下风速明显小于林冠层以上风速,且林冠下风速层差异微小,风速相对林冠层以上较稳定,对风力有显著的削弱作用。

Study on Microclimate Characteristics at Different Heights within a Eucalyptus Plantation

Atmospheric temperature,humidity,vapor pressure,wind speed characteristics were analyzed at four different heights（3.0,6.0,10.0 and 18.0 m） in a Eucalyptus plantation.There was an inversion of radiation phenomenon from above to below the canopy average temperatures under the canopy increased as height increased but above the canopy the trend was opposite this.Below the canopy,mean relative humidity was lower before the rainy season（February to April） and higher after the rainy season（May） and the daily range was consistently lower beneath the canopy compared to above the canopy.Average daily vapor pressure under the canopy was consistently higher than that above the canopy,but its daily range was lower below than above the canopy.Wind speed under the canopy was significantly less than that above the canopy layer but there was little difference in wind speeds between different heights under the canopy,and under the canopy wind speed was relatively stable compared with that above canopy;the canopy significantly weakened the wind force.