Ecohydrological Functions Of Litter In Main Plant Communities In The Songnen Grassland

The ecohydrological functions of litter in three main plants communities in the Songnen grassland were studied. The litter storage, water holding capacity, interception effect on rainfall, restraining effect on soil water evaporation , soil physical property and water holding capacity were quantitatively measured in three main plants communities. The results indicated that the litter storages in Leymus Chinensis,Chloria Virgata and Puccinellia tenuiflora communities ranged from 1.5 to 5.5t·hm^-2, being large for Leymus Chinensis community than that for Chloria Virgata and Puccinellia tenuiflora communities. The maximum water capacities of the whole litter layer ranged from 2.5 to 10.9t·hm^-2, being in the declined order of Leymus Chinensis, Chloria Virgata, Puccinellia tenuiflora, and the maximum water capacities were positively correlated with the litter storages. The maximum water holding rates were 208.4%,262.8% and 202.2%, respectively. The modified interception varied from 4.6 to 7.5t·hm^-2, in the declined order of Leymus Chinensis, Puccinellia tenuiflora, Chloria Virgata. The capacity of litter interception on rainfall were 6.57t·hm^-2,5.79t·hm^-2 and 5.26t·hm^-2, and the rates of litter interception on rain were 6.22%,5.52% and 5.23%, respectively in the three communities. With the increasing of rainfall the capacity of litter interception on rainfall increase, and the rate of litter interception on rain decreases. Under different levels of soil moisture, the soil water evaporation covered by litter with the thickness of 0.5cm～2cm was less than 7.95%～56.79% of the soil without litter covering. Such restraining effect increases with both litter thickness and soil water content. The maximum water storage varied from 1087.2 to 1265.4 t·hm^-2, and the order was Leymus Chinensis > Puccinellia tenuiflora > Chloria Virgata >waste grassland; The water holding capacity of non-capillary porosity varied from 42 to 90.6t·hm^-2, being in the declined order of Leymus Chinensis > Puccinellia tenuiflora > Chloria Virgata >waste grassland. This experiment will provide the basic data and scientific evidence for further studies on water and soil conservation functions of the grasslands and comprehensive evaluation of ecological function of f grasslands.