Spatial and temporal evolution of habitat quality and its shrinkage effect in shrinking cities: Evidence from Northeast China

Continued population loss in the context of urban shrinkage has led to the transformation and reconfiguration of urban land use space, which in turn has had a major impact on regional habitats and ecosystem services. To explore the status of habitat quality (HQ) in shrinking cities, based on land use data from 2010 to 2020, this study uses the InVEST model to analyze the spatiotemporal characteristics of HQ in shrinking cities. Then, we reveal the shrinkage effect of HQ in shrinking cities from the perspective of population change rate, and detect the dominant influencing factors of HQ in different types of shrinking cities with the help of geographical detector. The results show that:(1) From 2010 to 2020, the primary land use types in both shrinking and non-shrinking cities of the three northeastern provinces were forestland and cropland. However, there were significant differences in the area of construction land between the two categories of cities. (2) The HQ in both shrinking and non-shrinking cities showed a declining trend, yet the HQ index of shrinking cities was higher than that of non-shrinking cities. (3) The distribution of HQ in shrinking cities has a significant shrinkage effect, and HQ index gradually strengthens as urban shrinkage intensifies. Low-quality habitats have a strong distributional advantage in slightly shrinking cities, while severely shrinking cities tend to be dominated by high-quality habitats. (4) Population profile, economic development, industrial structure and built environment are important factors influencing the spatial heterogeneity of HQ in shrinking cities. However, the spatial determinants of HQ vary significantly among different types of shrinking cities in terms of dimensions and indicators, with two-factor interactions exerting a stronger influence than single-factor impacts. Based on the findings of this study, the government can formulate differentiated habitat protection measures, dynamically adjust, and optimize them according to the distribution characteristics of HQ grades in shrinking cities.