Effects of grazing exclusion on plant community and soil physicochemical properties in a desert steppe on the Loess Plateau, China

Although fencing is an effective restoration strategy used to achieve the global sustainability of grassland ecosystem, it is unclear from the literature whether fencing results in positive effects on soil physicochemical properties, plant diversity and the relationship between soil particle and soil chemical properties in a desert steppe on the Loess Plateau. Therefore, we selected fenced communities and grazed communities to study the effects of grazing exclusion on desert grassland on the Loess Plateau in China. Our results indicate that plant coverage, plant height, richness index, above- and below-ground biomass, root/shoot ratio, the number of grasses and the number of perennials increased significantly, whereas litter biomass, the number of forbs and annuals significantly decreased after approximately 12 years of fencing. Fencing also resulted in marked increases in ammonium nitrogen (AN) in the 0-10 cm soil depth, soil organic carbon (SOC), total nitrogen (TN), nitrate nitrogen (NN), clay and silt in the 0-30 cm soil depth and soil total phosphorus (TP) in 0-100 cm soil depth. Our results also indicated that SOC, TN, NN, clay, silt, sand and belowground biomass were significantly affected by land use type, soil layer and their interaction between land use type and soil layer. However, AN was affected by only land use type, and TP was affected by land use type and soil layer but not their interaction. In addition, there was s significant correlation between soil chemical properties (SOC, TN, TP, NN, AN) and soil particles (silt, clay and sand) in the 0-5 cm soil depth. As part of our ongoing research, this paper can produce substantial ecological benefits by contributing to the development of a more scientific strategy for grassland management on the Loess Plateau. (C) 2016 Elsevier B.V. All rights reserved.