Does Climate Change or Human Activity Lead to the Degradation in the Grassland Ecosystem in a Mountain-Basin System in an Arid Region of China?

Abstract

In mountain-basin systems in the arid region, grasslands are sensitive to the impacts of climate change and human activities. In this study, we aimed to resolve two key scientific issues: (1) distinguish and explain the laws of grassland ecosystem deterioration in a mountain-basin system and identify the key factors related; and (2) evaluate whether damaged grasslands ecosystem have the potential for natural revegetation. Hence, by combining spatial analysis with statistical methods, we studied the trends of the deterioration of the grassland ecosystem and its spatial characteristics in Kulusitai, a mountain-basin system in the arid region of Northwest China. According to our results, vegetation coverage and productivity exhibited significant decreasing trends, while the temperature vegetation drought index (TVDI) exhibited a significant increasing trend. Drainage of groundwater, because of increase in irrigation for the expanded irrigated area around Kulusitai, and climate warming were the critical triggers that leaded to the soil drought. Soil drought and overgrazing, resulting from the impact of human activities, were the main factors responsible for the deterioration of the grassland ecosystems. However, limiting the number of livestock to a reasonable scale and reducing the irrigated area may help to increase the soil moisture, thus promoting the germination of soil seed banks and facilitating the normal growth of grassland vegetation. Furthermore, based on analysis of the phenology of the grassland vegetation, the reasonable period for harvesting and storage is from July 29 to August 5. The results of this study provide a scientific basis and practical guide for restoring mountain-basin grassland systems in arid regions.

Spatiotemporal Variation and Drivers of Drought Based on TVDI in the Lower Reaches of the Jinsha River

“…The analysis of driving forces showed that temperature was the main cause of the increasing TVDI in areas with worsening drought (i.e., with significantly and nonsignificantly increasing TVDI). Especially in areas with significantly increasing TVDI, the variation of TVDI was related to temperature in 76% of the region; while an increase in temperature will lead to an increase in transpiration and a decrease in soil moisture content, resulting in increasing drought in the study area (Yuan et al, 2017; Yan et al, 2019b; Zhang et al, 2023). Therefore, the increase in temperature was the main major reason for the aggravation of drought in the study area.…”

Quantifying Grass Coverage Trends to Identify the Hot Plots of Grassland Degradation in the Tibetan Plateau during 2000–2019

“…Grassland covers about 40% of the global land surface [ 1 ], provides vital ecosystem services [ 1 , 2 ], and plays an essential role in food security, biodiversity maintenance, and sustainable development [ 3 , 4 ]. However, during recent decades, half of the global grasslands were degraded due to anthropogenic and natural factors [ 2 , 3 , 5 ]. As one of the major rangeland regions in the world, the Tibetan Plateau (TP) was also experiencing serious grassland degradation [ 6 , 7 , 8 , 9 ], resulted in declines of productivity, biodiversity, soil carbon and nutrients, and related socio-economic functions [ 9 , 10 , 11 , 12 ].…”

Analyzing Macro-Level Ecological Change and Micro-Level Farmer Behavior in Manas River Basin, China

“…Arid areas of Northwestern China experience glacier recession, the drying-up of lakes, decreased river runoff, vegetation decline, soil salinization and land desertification [1][2][3][4]. Such ecological degradation affects social and economic development and people's livelihoods.…”

“…Therefore, based on the above considerations, the aims of this study are to (1) analyze the relationships between farmers' land use behaviors and environmental degradation; (2) study farmers' feelings about and responses to environmental degradation; (3) put forward a new model of oasis expansion implementing land integration and realizing oasis connotation expansion; (4) guide farmers to adjust their land use behaviors to encourage the harmonious development of the social economy and the ecological environment in the Manas River Basin.…”