Effect of Grazing Exclusion on Vegetation Characteristics and Soil Organic Carbon of Leymus chinensis Grassland in Northern China

Jiao Chen,Haiping Tang

doi:10.3390/su8010056

Abstract

Overgrazing has caused vegetation destruction and soil degradation in Leymus chinensis grassland, the widely distributed type of grassland in northern China. To restore the degraded ecosystem, grazing exclusion was implemented in 1979, 1999, and 2004. However, changes in the vegetation and soil organic carbon (SOC) in different years of grazing exclusion have not been thoroughly elucidated. This paper examines the changes in vegetation characteristics (i.e., biomass, cover, richness, degree of succession, and shannon diversity index) and SOC under free of grazing (FG), 6 years (6 GE), 11 years (11 GE), and 31 years (31 GE) of grazing exclusion plots in the Xilin River Basin, China. The results indicate that the vegetation characteristics and SOC increased during the restoration process. Both the vegetation characteristics and SOC in 6 GE did not differ significantly from FG (p > 0.05), while these indexes in 11 GE were significantly higher than in FG. The differences between the vegetation characteristics and SOC in 11 GE and those in 31 GE were not significant. To meet the tradeoff between ecosystem conservation and utilization, further studies with multi-year observation should be conducted to identify the optimal duration of grazing exclusion and the grazing exclusion time threshold in L. chinensis grassland. This study provides valuable insights into sustainable grassland management in northern China.

Highlights

As a main type of terrestrial ecosystem, grassland plays a crucial role in providing substantial and effective ecosystem services [1,2]
The vegetation characteristics and soil organic carbon (SOC) did not differ significantly between the 11 GE plot and the 31 GE plot. These findings indicate that at least a decade of grazing exclusion is required for favorable improvements in plant cover, productivity, biodiversity, and SOC in L. chinensis grassland in this region
This study investigates the effect of grazing exclusion on three L. chinensis grassland plots with representative numbers of years of grazing exclusion in northern China

Summary

Introduction

As a main type of terrestrial ecosystem, grassland plays a crucial role in providing substantial and effective ecosystem services [1,2]. Previous studies have shown that degraded grassland induced by overgrazing is characterized by reductions in vegetation coverage, biodiversity, and biomass [5,6]. The physical and chemical properties of soil, soil organic carbon, dramatically deteriorated under excessive livestock grazing [8,9,10]. Both vegetation and soil degeneration have a negative impact on productivity, ecological functions, and ecosystem services [11]. Effective ecological actions must be taken to restore the degraded ecosystem and improve the environment

Objectives

Methods

Findings

Discussion

Conclusion