西藏原始林芝云杉林雨季林冠降水分配特征

利用2006-2007年对西藏米林县南伊沟原始林芝云杉(Picea likiangensis var.linzhiensis)林林外降水、穿透水和树干茎流定位观测数据,对林芝云杉林的林冠降水再分配特征进行研究。结果表明:西藏南伊沟的年降水量为716.4mm,主要集中在4-9月份,占全年降雨量的86.95%。在林芝云杉的生长季节(4-10月份),林冠截留量为338.6mm,占同期林外降水量的51.60%;林内穿透水量为316.3mm,占同期林外降水量的48.21%;树干茎流量仅为1mm,仅占0.19%。林内穿透水(Tp)、树干茎流(Sf)、林冠截留量(Ip)及林冠截留率(PIp)与林外降水量(p)之间的关系分别为:Tp=0.8622p-3.5229,r=0.9964;Sf=0.0004p1.4586,r=0.9458;Ip=1.2222p0.6341,r=0.874;PIp=253.6p-0.7008,r=0.9732。林芝云杉林雨季林冠降水的分配规律与该森林结构复杂、林分年龄高、胸高断面积大密切相关,说明该森林在涵养水源和保持水土等方面发挥着重要的作用。

Canopy interception and throughfall in a primary Picea likiangensis var. linzhiensis forest of Tibet

Rainfall partitioning in forest canopy plays an important role in hydrological cycles. Because the process that rainfall is partitioned by canopy into interception,throughfall and stemflow affects the volume and routine of rainfall that reaches the ground surface,the surface runoff causing soil erosion,and soil water supply for plant growth are altered. Although extensive researches have been conducted to examine the canopy interception,throughfall and stemflow in forest ecosystems across China,lacking of t...