Study on the Correlation between Ecological Service Value and Ecological Risk of Typical Mountain-Oasis-Desert Ecosystems: A Case Study of Aksu City in Northwest China

Abstract

Aksu City, located in the southern region of Xinjiang, China, holds the position of being the fifth largest city in Xinjiang. It holds significant ecological importance as a vital functional region for the management of desertification in China. To safeguard the ecological security of Xinjiang and preserve the ecological stability of Aksu City, it is crucial to examine the relationship between ecological service value and ecological risk, as well as the geographical and temporal changes in land use characteristics in Aksu City. This study examines the evolutionary characteristics and spatial correlation between ecological service value and ecological risk in Aksu City, using Aksu City as a case study. The analysis is based on five periods of land use data from 2000, 2005, 2010, 2015, and 2020. The study revealed the spatial and temporal patterns of landscape ecological risk and ecosystem service value in Aksu City from 2000 to 2020 using the landscape pattern index, ecological service value estimation, and ecological risk index. In addition, the study explored the interrelationship between ecological service value and ecological risk. The findings indicated that: (1) Bare land constituted the predominant land use category in Aksu City, accounting for over 81% of the total land use transfer over a 20-year period, encompassing a total area of 459.83 km2. (2) The total ecological service value (ESV) in the area experienced a decline of CNY 3.41 × 108 within the study’s time frame, exhibiting a decrease rate of 6.73%. Notably, grass and shrubland emerged as the primary contributor to the ESV, accounting for 33.25% of the total. (3) The ecological risk index (ERI) in Aksu City, within the period of 2000–2020, showed an increase in the interval from 0.2686 to 0.2877. The results indicated a decline in the overall ecological condition. The ecological risk level in Aksu City from 2000 to 2020 was dominated by lower and medium ecological risks. (4) Moran’s I values in Aksu City between 2000 and 2020 ranged from 0.428 to 0.443, which suggested a positive spatial correlation between ESV and ERI in the study area. The primary factor contributing to the heightened ecological risk in the study region was predominantly attributed to human activities such as urban expansion, agricultural production, and overgrazing.