This study investigated the effects of different grazing systems on plant communities, and examined the causes of Mongolian grassland desertification. The typical steppes near the Chinese-Mongolian border were studied using quadrat sampling and remote sensing methods. Aboveground biomass in the steppe areas differed significantly among the three grazing systems (p < 0.05): Biomass in the grazing-prohibited areas (455.9 g) was greater than that in the rotational-grazing areas (268.4 g) and the continuous grazing areas (122.2 g). Aboveground biomass was well correlated with the Soil Adjusted Vegetation Index (SAVI; y = 5600x 2 + 260x + 110; R 2 = 0.67; p < 0.05). The relative mean deviation between the aboveground biomass was calculated using this regression and the measured biomass was 29.1%. The Soil Adjusted Vegetation Index (SAVI) values for nomadic-grazing areas were greater than those for continuous-grazing areas in 1989, 2005, 2011, and 2016, and were significantly greater in 2011 and 2016. The SAVI values for the continuous-grazing areas were slightly, but not significantly greater, than those for the nomadic-grazing areas in 1993. Plant species that dominated in moderately degraded areas were most dominant in nomadic-grazing areas, followed by continuous-grazing areas and grazing-prohibited areas. Plant species that dominated in lightly and heavily degraded areas were most dominant in continuous-grazing areas, followed by nomadic-grazing areas and grazing-prohibited areas. Generally, continuous grazing caused more serious grassland degradation than did nomadic grazing, and nomadic-grazing areas tolerated more intense grazing than did continuous-grazing areas.

This study examines the effects of different grazing systems in two neighboring regions with similar biotic and abiotic factors, Nalan Soum in Mongolia and Naren Soum in Inner Mongolia, China. We employed the quadrat sampling method and remote sensing to set three perpendicular lines that dissect the boundary between the two countries, and seven lines parallel to the boundary to form a rectangular shape as a means to compare plant community response to different grazing systems under natural conditions. NDVI data is included in discussing the causes of Mongolian grassland degradation. The results of quadrat sampling and NDVI analysis show that rotational grazing has greater values for the quadrat's average height, total coverage, total individual density, and total aboveground biomass (p < 0.05), but has lower species richness than continuous grazing (p > 0.05).The NVDI values of rotational grazing in 1989, 2005, 2011, and 2016 were higher those of continuous grazing, and significant difference was shown in 2011 and 2016; the NDVI value of continuous grazing in 1993 was higher than that of rotational grazing, but did not show a significant difference. This indicates that different grazing approaches affect steppe ecological systems in different ways, despite their similar biotic and abiotic factors, as well as grazing intensity. Nonetheless, we find rotational grazing to be better for ecosystem vitality than continuous grazing, to some degree.

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