The impact of land use and land cover changes on the landscape pattern and ecosystem service value in Sanjiangyuan region of the Qinghai-Tibet Plateau.

Decades of intensifying human activities have caused dramatic changes in land use and land cover (LULC) in the ecologically fragile areas of the Qinghai-Tibet Plateau, which have led to significant changes in ecosystem service value (ESV). Taking the ecologically fragile Sanjiangyuan region of the Qinghai-Tibet Plateau as the research object, we focused on understanding the impact of LULC changes on the Sanjiangyuan's landscape pattern and its corresponding ESV, which was combined with a Markov-Plus model to predict LULC changes in 2030. The results showed: (1) from 2000 to 2020, the LULC of Sanjiangyuan has changed to varying degrees, respectively. In the central and southern regions where animal husbandry is the mainstay activity, the area of grass land converted to bareland had expanded; (2) from 2000 to 2010, the total regional ESV increased sharply. However, the total amount of ESV decreased from 2010 to 2020; (3) the overall ESV in the study area was observed to be trending down and is expected to decrease by approximately 4.25 billion CNY by 2030; (4) the fragmentation and complexity of regional landscape patterns will negatively affect local ecosystem stability and biodiversity. Overall, there is a strong temporal and spatial correlation between LULC and ESV. This study will provide a reference for the local government to provide targeted and sustainable land management policies, thereby promoting the improvement of the Qinghai-Tibet Plateau regional ecology value.

Multi-scenario analysis of land space based on PLUS and MSPA.

Land space is an important link between human social-economic activities and the evolution of the natural environment. Its changes can directly reflect the transformation process of mankind's activities on the surface system, and it is a core element of the study of global environmental change. In the research, based on the "three districts and three lines" classification method of national land spatial, the urban space, agricultural space, and ecological space of Tianjin were divided. Natural trend, economic development, cultivated land protection, and ecological priority were set as four simulation scenarios, which were predicted by the Markov-Plus model for the spatial pattern of national land in 2030. Data statistics and the MSPA model were used to quantitatively analyze Tianjin's future land space from two aspects of structure and pattern. The main conclusions were as follows: (1) The overall accuracy of the simulation results of the Markov-Plus model was 0.971, and its kappa value was 0.948. The simulation accuracy was relatively high, which provides a reference for future spatial simulation prediction in this area. (2) In different simulation scenarios, the changing trend of Tianjin's land space scale from 2020 to 2030 was that urban space continues to increase, while agricultural space and ecological space decrease successively. (3) Each simulation scenario achieves good results for spatial prediction under the condition of setting limiting factors. In the natural trend scenario, the spatial variability of the types is more complex, the boundaries are more fragmented, and the spatial reference value of the territory is lower.