The rapid urbanization process means that even moderate-sized cities can quickly become part of larger urban agglomerations, creating new urban zones. Urban Green Infrastructure (UGI) plays a crucial role in these clusters, acting as precious green spaces essential for maintaining ecological safety. This study combines fluctuation analysis based on Morphological Spatial Pattern with traditional landscape pattern analysis, comprehensively addressing the evolution of UGI in terms of quantity, characteristics, and morphology. We selected the Taiyuan-Jinzhong agglomeration as our study area, which is currently in an agglomeration process. The results demonstrated the critical role of surrounding mountains as natural ecological barrier zones. During urban agglomeration, management strategies focused on large-scale afforestation to ensure the quantity of UGI. However, this approach also led to a more clustered landscape with reduced connectivity. Additionally, linear or small-scale UGI types such as branch and islet have seen reductions over the past decade. Changes in internal morphological and complex fluctuations within UGI can harm the formation of ecological networks and potentially negatively affect biodiversity and ecological safety. The research highlights how ecological protection and urban planning policies can influence UGI fluctuations. Therefore, urban managers should not just concentrate on maintaining the quantity of UGI, but also give consideration to changes in its internal features and morphology. Before cities further agglomerate into larger urban clusters, it is crucial to address deficiencies in UGI, continuously improving type configurations and functional structures at the landscape scale. Through strategic planning of UGI, cities can mitigate ecological risks and foster sustainable urban development.

Urban green infrastructure (UGI) is critical for mitigating fine particulate matter (PM _2.5 ) pollution, a major obstacle to sustainable urban development. However, the morphological spatial patterns of UGI and their impact on PM _2.5 remain largely unexplored, as most related studies have focused solely on case studies. This study employed morphological spatial pattern analysis to document the national scale spatial distribution of seven UGI morphology space patterns (MSPs) across 288 Chinese cities. It verified the disparities of each MSP under varying geographic conditions and scalar categories. Using advanced interpretable machine learning methods that account for aggregated contribution of location features, the study confirmed the positive role of UGI proportion in mitigating PM _2.5 levels. Significantly, the findings revealed that smaller non‐core UGI areas, such as perforation and islet, exert a more pronounced positive impact on reducing PM _2.5 . Furthermore, the study explored the potential PM _2.5 risks facing Chinese cities due to temporal changes of UGI. The study results not only fill the gap in UGI research, but also contributes a feasible urban planning method and provide a basis for reducing PM _2.5 to promote sustainable urban development.

Green infrastructure (GI) effectively mitigates health effects associated with PM _2.5 and urban heat. However, the impact of GI's morphological characteristics on compound exposure remains unclear. With a large urban population, Chinese cities face significant compound exposure risks, yet national‐scale GI planning strategies addressing this issue are lacking. This study incorporates 374 Chinese cities, quantifying and mapping the spatial distribution and changes of four spatial morphological structures of GI, seasonal PM _2.5 pollution, and summer daytime and nighttime land surface temperature over the past 20 years. Results indicate that core areas are larger and have expanded significantly, failing to effectively mitigate compound exposure risks. Although connectors represent a smaller scale of GI, they play a significant and positive role in mitigating compound exposure risk, especially when their proportion exceeds 2% of urban space. We suggest that urban planners prioritize connectivity‐oriented GI strategies to effectively mitigate compound exposure risks.