雷州半岛尾巨桉人工林林下穿透雨特征研究

Precipitation Throughfall Characteristics of Eucalyptus urophylla×E.grandis Plantations on the Leizhou Peninsula

为深入了解桉树生态水文过程,正确认识桉树水文功能,本文通过野外实测法,对不同林龄尾巨桉林下穿透雨进行连续观测,并结合林外降雨量分析尾巨桉人工林林下穿透雨特征及其与降雨的关系。结果发现:尾巨桉各林龄林下穿透雨量与降雨量呈极显著正相关线性模型(P<0.01);林下穿透雨率与降雨强度呈极显著正相关(P<0.01),截留率与降雨强度呈极显著负相关(P<0.01),变异系数随降雨强度的增大先增大后减小,且两者均与降雨量无显著相关性;干湿季林下穿透雨率差异显著,湿季显著大于干季(P<0.05),最大穿透雨率及最小穿透雨率分别是干季的1.17倍和3.2倍。

For an in-depth understanding of ecological processes of Eucalyptus plantations with respect to key hydrological factors,this article reports on field surveys carried out to observe and quantify throughfall of rainfall in Eucalyptus urophylla × E.grandis plantations of different ages.This involved analysing the throughfall characteristics of eucalypt plantations and analysed relationships between total rainfall and throughfall.The results showed that the throughfall and rainfall of E.urophylla × E.grandis plantations showed significant,positively linear relationships for all plantation ages examined.Also,the penetration rate of rainfall was found to have a highly significant,positive correlation with rainfall intensity（P〈0.01）,the interception rate was very significantly negatively correlated with rainfall intensity（P〈0.01）,the coefficient of variation tended to increase as rainfall intensity initially increases but then tended to decrease.Significant differences were found in rainfall penetration through plantation canopies between dry and wet seasons,and those of the wet season were significantly greater than those of the dry season（P〈0.05）.Minimum and maximum rainfall penetration rates during the wet season were 3.2 and 1.2 times greater,respectively,than those observed during the dry season.