Abstract:

Litter mass and the distribution pattern in 4 different microhabitats under 5 kinds of Karst forest vegetables (Lithocarpus confines+Itea yunnanesis,P1; Platycarya longipes+Itea 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.

Key words: Karst, microhabitats, litter mass, water hold capacity, hydrological effects