为探讨苏南丘陵区毛竹林林内冠层水文特征,准确揭示冠层水文动态变化规律。2013年1月到2014年12月连续两年对苏南丘陵区毛竹林(phyllostachy edulis)林内水文效应进行了定位监测,使用自制装置收集树干径流、集水槽收集穿透雨、雨量筒收集林外降雨。研究不同的降雨量等级、降雨强度等级下,树干径流、穿透雨和林冠截留随降雨特征变化规律,并建立了回归模型,通过降雨量、相对湿度、降雨强度、风向、空气温度、相对湿度、叶面积指数定量分析了影响林冠截留的主要因素。结果 表明:研究期内苏南丘陵区毛竹林外累计降雨量为2 419.1 mm,林内累计穿透雨量、树干径流量、林冠截留量分别占同期降雨量的58.70%,6.14%,35.16%; 降雨量与穿透雨量、树干径流量呈现极显著线性关系,与林冠截留量的线性相关性较显著; 毛竹林生长旺季月平均叶面积指数不断增加的同时,各月林冠截留总量随之增加,月平均林冠截留率整体呈下降趋势。研究区毛竹林林冠部分和树干的持水能力分别为0.38 mm,0.1 mm,且降雨事件中形成树干径流的最小雨量为1.30 mm。通过相关性分析得到影响毛竹林林冠截留主要气象因子为降雨量和降雨强度。研究可为苏南丘陵区毛竹林降雨再分配特征研究提供科学的数据支撑,为毛竹林集约发展提供理论基础。
To investigate the canopy hydrological characteristics of the bamboo forest in the hilly area of southern Jiangsu, and to reveal the dynamics of canopy hydrology, the hydrological effects of the Phyllostachy edulis forest in the hilly area of southern Jiangsu were monitored for two consecutive years from January 2013 to December 2014. The trunk flow was collected by the self-made device, throughfall was collected by the sump, and the rain outside of the forest was collected by cylinder. The changes of trunk runoff, throughfall and canopy interception with rainfall characteristics were studied under different rainfall levels and rainfall intensity levels, and regression models were established, the main influence factors on canopy interception were quantitatively analyzed through rainfall, relative humidity, rainfall intensity, wind direction, air temperature, relative humidity, leaf area index. The cumulative rainfall outside of the bamboo forest in the hilly area of southern Jiangsu was 2 419.1 mm during the study period. The cumulative rainfall, trunk runoff and canopy interception in the forest accounted for 58.70%, 6.14%, and 35.16% of the rainfall during the same period, respectively. The amount of rainfall has the significantly linear relationship with the amount of throughfall and trunk runoff, and has the linear correlation with the canopy interception. The average monthly leaf area index of the bamboo in growing season was increasing, and the monthly total amount of canopy interception increased over the time. The average canopy interception rate showed the decreasing trend as a whole. The water holding capacity of the canopy part and trunk of the bamboo forest in the study area was 0.38 mm and 0.1 mm, respectively, and the minimum rainfall causing the trunk runoff among the rainfall events was 1.30 mm. It can been seen that the main meteorological factors affecting the canopy interception of the bamboo forest are rainfall and rainfall intensity through correlation analysis. This study can provide the scientific data support for the study of rainfall redistribution characteristics of bamboo forest in the hilly area of southern Jiangsu Province, and provide the theoretical basis for the intensive development of bamboo forest.
