Water Conservation Function of Typical Plant Communities in the Small Watershed of the Three Gorges Reservoir Area
The regional ecological hydrology and soil erosion processes were greatly affected by the changes in water conservation function. The Three Gorges Reservoir Area is a typical ecologically fragile area and a key area for soil erosion control in China,clarifying the water conservation function of different plant communities is of great significance for improving its ecological environment. Combined with field sampling and indoor anal-ysis methods,the characteristics of litter accumulation,water holding process,and the water source conser-vation capacity of litter and soil layers in typical plant communities in the reservoir area were systematical-ly analyzed. The results indicated that litter accumulation (varied from 0.43 to 5.76 t·hm-2) and water holding capacity differed significantly between different plant communities. The humid and hot climate conditions in the reservoir area led to less undecomposed litter than semi decomposed litter for all plant communities. Moreover,the maximum water holding capacity and effective retention capacity of undecom-posed litter were both less than those of semi decomposed litter for all plant communities except for Euca-lyptus and grassland. Furthermore,the water holding capacity and water absorption rate of undecomposed and semi decomposed litters were increased and decreased with the increase of litter immersion time as log-arithmic and power functions,respectively. There were certain differences in the effective water storage capacity of 0-20 cm soil layer among different plant communities. The effective water storage capacity of the Eucalyptus spp. was the maximum (208.42 t·hm-2),whereas shrubland was the minimum one (63.90 t·hm-2). Overall,the effective retention capacity of typical plant communities in the reservoir area was shown as follows:Eucalyptus being the maximum,then reducing as grassland,Cupressus fune-bris,Pinus massoniana,Citrus reticulata,sloping farmland,shrubland. The water conservation capacity of all plant communities was dominantly controlled by the water conservation capacity of the soil layer.
water conservationlitter hydrological effectsoil hydrological effectThree Gorges Reservoir Area
万方数据
维普
