Dynamics of Root Development of Herbaceous Vegetation on Abandoned Land on the Loess Plateau, China

摘要

Currently, returning farmlands to forest and grassland was one of the main measures to ecological construction in West China, especially on the Loess Plateau. Returned farmlands have been the important land type in these districts. In this study, vertical root distribution characters of vegetation at different succession stages were investigated by soil drilling method. The results indicated that the root distribution patterns of different root indexes (root biomass, root length, etc) changed with the increase of abandoned times. At the earlier stages, more roots were distributed in the deeper soil layer, which is of great importance to ameliorate and improve the soil physical and chemical conditions for later species. With the increase of abandoned time, more roots were concentrated in the surface soil layer. By calculating the root extinction coefficient,β, the results indicated that the value of β at earlier succession stages was bigger than that of later stages, which was help to verify that there were more root distributed in deeper soil in earlier abandoned years, and more roots were tended concentrate in surface soil with the increase of abandoned years.