Objectives The integration and optimization of natural protected areas constitute an essential foundation for the establishment of a comprehensive natural protected areas system, with national parks representing the primary component. It is of great significance to study the changes in landscape patterns and habitat quality before and after the integration and optimization of natural protected areas in Fuzhou, which will allow the rationality of integration and optimization measures to be evaluated and the changes in the ecosystem of natural protected areas to be mastered.

Methods Based on the integration and optimization results of natural protected areas and land use/cover data in Fuzhou, this paper comprehensively used GIS spatial analysis, Fragstats software, and InVEST model to obtain landscape patterns and habitat quality index and perform correlation analysis on them.

Results The results showed that: (1) After integration and optimization, The PD, ED, and LSI index of natural protected areas of Fuzhou decreased at the landscape level, while the AREA_MN、SHDI、SHEI、COHESION、AI index demonstrated an increase, indicating that the overall landscape fragmentation, complexity, and landscape heterogeneity decreased, and spatial connectivity increased. (2) Following integration and optimization, the PD, ED, SHDI, and SHEI indexes of the geopark were 3−5 times higher than those before integration, indicating an increase in fragmentation and heterogeneity. In contrast, the PD, ED, SHDI, and SHEI indexes of the marine park have decreased significantly and were approaching zero, suggesting a tendency towards unitariness. (3) After integration and optimization, the overall habitat quality of natural protected areas in Fuzhou has been enhanced. The habitat quality of the geopark has decreased by 10.13%, and the habitat quality of some scenic spots was poor. (4) The habitat quality of protected areas was significantly positively correlated with COHESION and AI indices, while it was significantly negatively correlated with the PD, ED, SHDI, and SHEI indices.

Conclusions The comprehensive results demonstrated that the integration and optimization measures of natural protected areas in Fuzhou were generally reasonable and feasible and that the landscape pattern and habitat quality have been improved. However, further improvements are necessary with regard to the planning and management of related natural protected areas, in order to address issues such as the single landscape of marine parks and the increased fragmentation of geological parks.