关键词: 喀斯特石漠化, 土地利用, 土壤理化性质, 土壤种子库

Abstract:

By investigating the soil physical and chemical properties and soil banks of three different applied soils (Ⅰclosing hill for regeneration,Ⅱretired farmland for forest land,Ⅲfarmland) in karst rock desertification zone in Puding City of Guizhou Province of China,it was found that soil physical and chemical properties,soil banks of different applied soils were distinctly different.Soil bulk density and capillary porosity dropped with the increase of disturbance(Ⅰ＞Ⅱ＞Ⅲ).The total soil porosity and noncapillary porosity increased with disturbance(Ⅲ＞Ⅱ＞Ⅰ).The changes of soil bulk density were slight,the soil textures were similar in each type.The organic matter content of Ⅱ was lower compared to Ⅲ andⅠ.The change of type Ⅰ was due to the formation of forest environment.Organic matter content,total N, total P,dissoluble N dropped with the increase of soil depth.The disturbance reduced the change of soil chemical properties.There are slight differences in soil bank species under different land use modes and quantities of seeds,species decreased with the increase of depth.Seeds mostly lay in 0～5 cm soil,and the difference of seed number was significant (〖WTBX〗p〖WTBZ〗=0.021 897),whereas the difference of species was not (〖WTBX〗p〖WTBZ〗=0097 628).Disturbance of soil could accelerate the distribution of seeds to deeper soils,and retired farmland for forest land would benefit soil quality recovery.

Key words: karst rocky desertification, land use, soil physical and chemical properties, soil banks