太岳山不同郁闭度油松人工林降水分配特征

Characteristics of precipitation distribution in Pinus tabulaeformis plantations under different canopy coverage in Taiyue Mountain

利用2011年5—9月生长季观测的30场降雨数据,分析了山西太岳山不同郁闭度下油松人工林林冠截留、穿透雨以及树干茎流与降雨量的关系,以及林冠截留过程的特点。结果表明:(1)实验观测期间,该地区降雨总量为634.79mm,单次平均降雨量为21.16mm,单次最大降雨量为58.15mm,单次最小降雨量为0.54mm。其中,8月份的降雨总量最大,为190.77mm,6月份的降雨总量最小,为41.81mm。(2)郁闭度为0.8的油松人工林林冠截留量与降雨量呈一元线性关系,郁闭度为0.7、0.6和0.5均呈幂函数关系;对于各郁闭度的油松人工林,其林冠截留率与降雨量均呈对数函数关系;穿透雨量、树干茎流量与降雨量均呈明显的一元线性关系,穿透雨量和树干茎流量都随着降雨量的增加而增加。(3)不同郁闭度油松人工林之间林冠截留、穿透雨和树干茎流不同,总的趋势为随着郁闭度的减小,林冠截留量减小,穿透雨量增大,树干茎流量增大。林冠截留量与郁闭度表现出正相关关系,而穿透雨量、树干茎流量都与郁闭度表现出负相关关系。(4)各郁闭度林冠截留量、穿透雨量和树干茎流量的月动态变化与总降水量的月变化基本一致。

A study was conducted on Pinus tabulaeformis plantations in the Taiyue Mountain of Shanxi Province to analyze the relationship between canopy interception, throughfall, stemflow and rainfall using data from 30 rainfall events observed from May to September, 2011. The results were as follows： （1） During the research period, the total precipitation was 634. 79mm. Average rainfall was 21.16mm, the maximum rainfall was 58.15ram, and the minimum rainfall was 0.54mm. The largest monthly rainfall occurred in August, was 190.77 mm, the minimum monthly rainfall happened in June, was 41.81 mm. （2） The correlation between canopy interception with 0.8 canopy coverage and rainfall was fitted by linear function, while canopy coverage of 0.7, 0.6 and 0.5 were all be fitted by power function. The correlation between canopy interception rate for all canopy coverage and rainfall was fitted by power function. The correlation of all canopy coverage between canopy throughfall, stemflow and rainfall was fitted by linear function. Both of canopy throughfall and stemflow increased with increasing rainfall. （3） Different canopy coverage of Pinus tabuleformis produces different canopy interception, throughfall and sternflow. In general, with the decrease of the canopy coverage, the canopy interception decreased, throughfall increased, and the trunk stemflow increased. Canopy interception showed a positive correlation between canopy coverage, while throughfall, stemflow and canopy coverage showed a negative correlation. （4） The monthly dynamic changes of canopy interception throughfall and sternflow was consistent with that of rainfall