Effectiveness of shrub planting and grazing exclusion on degraded sandy grassland restoration in Horqin sandy land in Inner Mongolia

Abstract

Effective methods of restoring lands stressed by desertification and sand movement are needed. The stabilization of sand dunes with shrub planting with the help of straw checkerboard (PCS) and grazing exclusion was evaluated in degraded sandy grasslands in Horqin sandy land, China. The characteristics of vegetation and soil chemical properties were studied in PSC sites and grazing exclusion sites 0, 6, and 12 years after implementation. Natural community sites were also examined in 2012. Results showed that the implementation of PSC and grazing exclusion not only significantly (P<0.05) promoted the number, density, coverage, and Shannon–Weiner diversity of plant species, but also enhanced the accumulation of total carbon (C) and total nitrogen (N) and accelerated the increase of C/N ratio in soil. In addition, the recovery of vegetation density, coverage, and Shannon–Weiner diversity occurred sooner in the PSC sites than in the grazing exclusion sites. The PSC sites became stable at 6 years. The soil chemical properties also changed more in the PSC sites than in the grazing exclusion sites, but did not become stable state. The restoration of soil chemical properties had a lag effect with respect to vegetation characteristics in degraded sandy grasslands. These findings also suggested that PSC and grazing exclusion are useful methods for accelerating vegetation development and restoring deserted lands. In addition, implementation of PSC was more effective than using grazing exclusion alone. For this reason, it should be adopted in sandy grasslands in the Horqin region in China.