The effects of erosional topography on soil properties in a Pinus massoniana forest in southern China

Understanding the distribution and properties of soils is necessary for planning and implementing sustainable land use and for the rehabilitation of degraded land, especially for the Pinus (P) massoniana forests typical in the hilly area of southern China where the red soils have been badly eroded. The long-term soil erosion affected the local ecological environment greatly. To control soil erosion and restore the ecological environment, the P massoniana forests were widely planted in this region, and the planted area was 142,000 km(2) (54,830 mi(2)) at the end of the 1980s. This study analyzed the effects of three erosional topographies on the soil properties of the P massoniana forests in this hilly area. Soil physical and chemical indices, microbial populations, and enzymatic activities were higher in gullies than on concave and ridge slopes. The relationships amongst these parameters differed significantly in the topographies, being more positively correlated for the gullies than for the concave and ridge slopes. The grey relational degree between soil properties and gullies was 0.93, which was the highest amongst the three topographies. The microenvironment formed by gullies improved the soil properties, providing favorable conditions for vegetational restoration. The results of this study are helpful to understand the potential effects of erosional topography on soil properties, land-use adjustment, and vegetational restoration in the hilly red soil area of southern China.