Spatial Changes of Suburban Forest Ecological Functions and Their Impact on Ecological Equity in the Process of Urbanization—A Case Study of Jiangning District, Nanjing, China

Abstract

After the transformation of counties in urban suburbs into districts, the rapid urbanization and industrialization process in China’s developed regions had a huge impact on the spatial distribution and equity of the suburban forest ecological functions. Accurately describing this impact could provide an important reference for the construction of suburban forest engineering and for ecological environmental planning. Jiangning District of Nanjing City, China, was selected as the research area, while the forest resource planning and design survey data in 2007 and 2017, together with the demographic data of the study area, were collected as the main information sources. Following the establishment of the forest ecological function evaluation indicators and the analysis of the spatial change of the forest ecological functions, the Gini coefficient was calculated to analyze the changes of the regional ecological function equality. The results showed that: (1) Compared with 2007, the proportion of areas with low forest ecological functions (abbreviated as FEF) in the study area in 2017 showed a downward trend, and the proportion of areas with medium and high FEF showed an increasing trend; (2) Compared with 2007, the forest landscape in the study area in 2017 was severely fragmented, the spatial aggregation of the FEF showed a significant decline, and the FEF developed towards a direction of spatially balanced distribution; (3) During 2007–2017, the sub-compartments with high-value FEF in the study area (hot spots) shifted to the northwest, where the economy was developed and the population density was higher, and the sub-compartments with low-value (cold spots) shifted to the south, where the economy is underdeveloped and with lower population density; (4) From 2007 to 2017, the Gini coefficient of the FEF in the study area decreased, indicating that the regional ecological equity had initially improved. The urbanization and industrialization process of the urban suburbs is a double-edged sword. On the one hand, the process has caused the fragmentation of forest landscape, the decline of the forest area, and the unbalanced spatial distribution of the population. On the other hand, the huge material wealth and human capital accumulated through industrialization have promoted regional ecological equity and improved the living environment of the local residents.