Spatio-temporal variations of ecosystem health in the Liuxi River Basin, Guangzhou, China

Abstract

Ecosystem health is an important research topic. Several studies have mainly focused on ecosystem health assessment (EHA) on a large or medium scale, with only a few studies using small grids as research units. Based on the Vigor–Organization–Resilience–Services (VORS) model, which can adequately compute multiple ecosystem values for each land use type, this study used a scale with a 250 m × 250 m grid as the spatial research unit to quantitatively and dynamically assess the ecosystem health and analyze its spatial implications in the Liuxi River Basin, Guangzhou, China. The results showed that the ecosystem health level of each land use type is ranked as follows: water areas > shrublands > grasslands > wetlands > broadleaf forests > drylands > construction land. The amount of construction land area rapidly increased from 2005 to 2018 at the cost of a substantial loss of broadleaf forests, shrublands, and wetlands, which led to a decline in ecosystem health values. Thus, anthropogenic activities such as urbanization and deforestation were the main driving factors affecting land use changes and spatial distribution of ecosystem health. Furthermore, the correlation between ecosystem services (ES) and ecosystem health was the strongest, indicating that ES was a key indicator contributing to ecosystem health in the Liuxi River Basin. The ecosystem health of the Liuxi River Basin had a significant positive spatial aggregation effect which gradually increased from 2005 to 2018. The high–high aggregation areas were mainly clustered in water areas and grasslands, and the low–low aggregation areas were mainly clustered in construction zones and paddy fields. This study provides an important reference for evaluating ecosystem health based on the VORS model, ecological conservation, and the management of small basins in the context of rapid urbanization.