贵州喀斯特山地5种森林群落的枯落物储量及水文作用

摘要

Litter mass and the distribution pattern in 4 different microhabitats under 5 kinds of Karst forest vegetables ( Lithocarpus confines + ltea yunnanesis, P1; Platycarya longipes + ltea yunnanesis, P2; Platycarya longipes + Quercus aliena, P3; Platycarya longipes + Rosa cymosa, P4; Platycarya longipes + Rhamnus hetrophylla, P5 ) in Puding, Guizhou,were investigated and calculated. Hydrological characteristics of the litter, such as the maximum water storage capacity,water absorption speed curve and the abilities of restraining soil water vaporization were studied. The result showed that the thickness of litter was between 2.7 - 13.7 cm on the forest floor, while the litter mass was between 4.9 - 9. 1 t· hm -2 The maximum water storage capacity ranged from 1. 608 to 3. 445 kg· kg-1, with P5 ＞ P4, P3 ＞ P2 ＞ P1. The relationship between the water absorption speed of litter and immerse time was fitted to equation of V = at-b. The soil evaporation speed was evidently reduced by the coverage of litter. The thicker the litter as, the lower the speed was. The abilities of restraining soil evaporation by litter under 5 different forests were significantly different. P1 and P5 were highest, followed by P4, and then P2 and P3.%在贵州省普定县喀斯特山地5种森林类型的4种小生境中进行枯落物储量和持水能力调查,研究枯落持水过程和不同厚度(2,4,6,10 cm 4个梯度)枯落物抑制土壤蒸发的作用.结果表明:5种森林类型的枯落物层平均厚度变化在2.7～13.7 cm,枯落物总储量在4.9～9.1 t·hm-2.枯落物最大持水量范围为1.608～3.445kg·kg-1,其排序为圆果化香-异叶鼠李林>圆果化香-小果蔷薇林和圆果化香-槲栎林>圆果化香-云南鼠刺林>窄叶石栎-云南鼠刺林.不同森林类型枯落物吸水速率与浸水时间的关系为V=at-b;有枯落物覆盖的土壤蒸发速率远远小于无枯落物覆盖土壤,并随着枯落物厚度递增而递减.5种森林类型枯落物层的土壤蒸发抑制作用有显著差异,窄叶石栎-云南鼠刺林和圆果化香-异叶鼠李林较强,其次为圆果化香-小果蔷薇林,圆果化香-云南鼠刺林和圆果化香-槲栎林较弱.