宁夏六盘山水源区华山松次生林的生长季水量平衡与产流特征

The characteristics of water budget and water yield of the Pinus armandii secondary forest in the waterhead area of Liupan Mountains,Northwest China

为揭示典型森林生态系统对水文过程和产流功能的调控机制,文中在宁夏六盘山区,选择了华山松次生林样地,观测了2011年生长季(5月24日至10月20日)的水文过程,分析了水量平衡与产流特征。结果表明:2011生长季总降水量为724.3mm;华山松林分冠层截留量(率)为102.3mm(14.13%);林下降水量(率)为622.0mm(85.87%);枯落物层渗漏水量(率)为424.3mm(58.59%);0-30cm土层渗漏水量(率)为275.9mm(38.09%)。华山松林的生长季总蒸散为477.1mm,各蒸散分量(mm)对总蒸散的贡献表现为林木蒸腾(222.9)>林下蒸散(151.9)>植被截持(102.3)。水量平衡计算表明,该年生长季降水量可充分满足华山松林蒸散耗水需要,林地产水量(0-30cm土层的净流出量)为252.7mm。

In order to reveal the regulatory mechanism of hydrological process and water yield in typical forest ecosystem, the representative stand of Pinus armandii secondary forest were selected in the Liupan Mountains, Ningxia in Northwest China. The observation of hydrological processes was carried out in the growing season of 2011 （May 24 to October 20）. The main characteristics of the water budget and water yield of the forest stands were analyzed. The main conclusions are described below. The gross precipitation in the growing season of 2011 amounted to 724.3mm. The canopy interception depth （rate） in the Pinus armandii secondary forest was 102. 3mm（14. 13% ）. The depth （rate） of rainfall under canopy was 622.0ram（85.87% ）. The leakage depth （rate） under humus layer was 424.3mm （58.59%）. The leakage depth （rate） under the 0 -30cm soil layer was 275.9mm（38.09% ）. According to the measurement, the evapotranspiration of Pinus armandii secondary forest was 477. lmm in growing season, the contribution of evapotranspiration components was in the order of： tree transpiration（222.9mm） 〉 floor evapotranspiration（151.9mm） 〉 canopy interception（102.3mm）. The calculation of water budget in growing season of 2011 indicated that the rainfall was sufficient to meet the demand of evapotranspiration in the Pinus armandii secondary forest stands studied. The water yield （i. e. , the net out- put from soil layer of 0 -30cm） performed as 252.7mm.