【摘要】 水文功能是森林生态功能的重要方面,为了解桉树人工林的水文生态效应,采用定位研究并结合室内测定的实验方法,研究了广东肇庆桉树人工林冠层降雨再分配、凋落物持水能力、土壤水分物理及蓄水能力。结果表明,研究期间(2006-05-2007-05)的大气降雨量为2016.7mm,通过林冠层后降雨被重新分配,穿透降雨量、树干茎流量和林冠截留量分别占总降雨量的85.70%、3.62%和10.68%。产生树干茎流的临界降雨量为3.93mm,穿透雨量、树干茎流量与林外降雨量均呈极显著正相关(P<0.01);林冠截留率与降雨量呈显著的负相关(P<0.05),降雨量超过20mm后,林冠截留率基本保持稳定。本研究桉树人工林的凋落物最大持水量为4.27mm,凋落物中树叶的最大持水量最大,为2.54mm。0-100cm土层的最大蓄水量为470.06mm,其中非毛管蓄水量为98.22mm,土壤总孔隙度和非毛管孔隙度随土壤深度增加呈递减趋势;0-10cm土壤层的初渗速率和稳渗速率分别为25.03mm.min-1和8.83mm.min-1,且随土壤深度增加而逐渐减小。更多还原

【Abstract】 The hydrological function is one of the important ecological functions of forest.To understand the eco-hydrological effects of eucalyptus plantation,we studied the canopy interception,rainfall redistribution and water-retaining capacity of litter and soil based on fixed field observation and measurement of laboratory in Gaoyao,Zhaoqing City,Guangdong Province,China.The results indicate that among the cumulative gross rainfall(2016.7mm)generated during the period from Apr.2006 to Apr.2007,throughfall,stemflow and canopy interception account for 85.70%(1728.4mm),3.62%(72.9mm),and 10.68%(215.4mm),respectively.The stemflow can be produced only when the precipitation is more than 3.93 mm.The throughfall and stemflow are distinctly positive related to the precipitation(P<0.01)and the values of the interception ratio to gross rainfall have a distinctly negative relationship to the precipitation(P<0.05).The value of interception ratio to gross rainfall keeps generally steady when the precipitation is more than 20 mm.The results also show that the water-capacity of litter is 4.27mm,and among the total 4.27mm,the capacity from the part of leaves(2.54 mm)is the best among all kinds of components of litter.The maximum water-capacity of the soil layer from 0 to 100 cm depth is 470.06 mm,and the non-capillary water-capacity accounts for 20.90%(98.22mm)of the total.Both of the total and non-capillary porosities show a decreasing trend with the increasing of soil depth.The initial and steady infiltration rates in the surface(0-10 cm)are 25.03 mm·min-1 and 8.83 mm·min-1 respectively,and also decrease with the increasing of soil depth.更多还原