Impact of vegetation restoration on soil properties in near-surface fissures located in karst rocky desertification regions

Abstract

Karst rocky desertification and vegetation restoration have become major environmental and social problems throughout the world. In regions facing rocky karst desertification, any form of residual soil is pivotal to vegetation growth and the restoration of rocky desertification. The goals of this study were to discover the impact of vegetation restoration on soil properties in near-surface fissures of karst rocky desertification regions, and analyses of the physical and chemical properties of soil and stable isotope techniques were used to achieve these goals. We found that the morphological structures of karst near-surface fissures are diverse. Fissures with grass and shrubs exhibit improved soil bulk density and more fine soil particles than those with other vegetation. Fissures with shrubs have higher soil field capacity, an increased capillary water content and a greater field capacity, whereas fissures with grass display greater fertility, particularly with respect to hydrolysable nitrogen, and greater available phosphorus and potassium contents, which create conditions that are superior to those found in areas with other crops, shrubs and even trees. Karst near-surface fissures are the optimal locations for vegetation restoration in areas of karst rocky desertification. Fissures with grass have a better soil structure, a higher water content and improved fertility compared with other fissure with growing crops, shrub grasses and forests with certain soil degradation. The use of grasses should be prioritized to improve soil conditions and to advance sustainable land use during the implementation of vegetation restoration projects in karst rocky desertification regions, particularly in highly fissured areas.