Study on zoning of livestock carrying potential based on spatial distribution of soil organic matter on the Bashang Plateau of northern China

Abstract

An understanding of the existing patterns of soil spatial heterogeneity is needed to clarify the potential of carrying livestock in different grassland regions, so as to provide an important reference and data support for the calculation of stock capacity and the establishment of reasonable grazing prohibition areas and times. Under the same vegetation coverage state, soils with different resilience capabilities will show different livestock carrying capacity. Thus, this study aimed to analyze the effect of soil organic matter as an indicator of soil resilience capabilities on the zoning results of livestock carrying potential, and to discuss the vegetation changes in different potential zoning over the years. By combining qualitative and quantitative methods, the weights of different indicators influencing livestock carrying potential were calculated. The results of this study show that, except for the unique effects of drought, vegetation coverage improved from 2000 to 2017 and that the most significant improvements were observed in Fengning and Guyuan Counties after grazing prohibition. The degraded area in Weichang County, which had good basic vegetation coverage, was the largest in the past many years, accounting for 5.3% of the local area. However, the vegetation coverage affected by the natural environment in Kangbao County has remained basically unchanged for many years. Soil organic matter participates in the zoning, which reflects the spatial variability in the livestock carrying potential. The calculation results of this work show that the study area can be divided into three levels of carrying potential (high, medium and low) and conservation area. Among the various regions, the high-potential area of Fengning County accounts for the largest proportion, followed by Weichang County, with proportions of 14.1% and 13.6%, respectively. Considering the proportions of high- and moderate- potential areas, the livestock carrying potential of the six counties decreased in the following order: Weichang, Fengning, Guyuan, Zhangbei, Shangyi and Kangbao. According to the multi-year changes in vegetation and the characteristics of the degraded spatial distribution in various regions, the high-potential areas should be normal grazing to increase grassland biodiversity, while the medium-potential areas and low-potential areas can be grazed by restricting the number of livestock and sporadically, respectively, to enhance grassland utilization.