Assessing landscape ecological risk in the Southern Hill and Mountain Belt of China: A 30-year analysis and future projection

Abstract

Hills and mountains cover approximately 25 % of Earth’s landmass; therefore, investigating landscape ecological risk (LER) in these regions is imperative for ecosystem management. Hilly and mountainous regions susceptible to influences such as desertification and erosion include the Southern Hill and Mountainous Belt (SHMB) in southern China. Over the past 30 years, the SHMB has undergone significant changes, offering an excellent research case. A comprehensive assessment of the ecological status of this region is crucial for the protection and management of the ecosystems in the SHMB. This study assessed the LER of the SHMB, identified influencing factors over the past 30 years, and utilized a patch-generating land-use simulation model (PLUS) to project future land use and LER. Accounting for more than 90 % of the total area, cropland and forestland were the two most common land use types in the SHMB. From 1990 to 2020, impervious surface and water area saw obvious increases, rising by 154 % (from 1209.37 km2 to 3073.59 km2) and 21 % (from 1584.78 km2 to 1924.8 km2), respectively. Grasslands and shrublands decreased by 54 % and 34 %. It is anticipated that there will be little change in land-use types by 2030 compared to 2020. Additionally, the overall LER in the SHMB was low, with low- and medium–low-risk representing around 70 % of the overall risk. The general state of LER improved during the research period but did not converge. Specifically, the LER intensity did not decrease although the total LER showed a declining trend. In the western portion of the research region, the karst area displayed an increasing LER, and the severity of the high-risk area increased. Furthermore, natural factors promote the restoration of LER. For example, the abundance of hydrothermal conditions (i.e., increased temperature and precipitation) promotes the recovery of vegetation growth and reduces the LER. Human activities, such as the construction of stations, highways, and an increasing population, exacerbate LER, contributing to an increase in LER. This study offers helpful guidance for formulating ecological conservation strategies to maintain the ecological balance and sustainability of hilly and mountainous regions.