Aruhan Olhnuud

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.

Apple is one of the most widely cultivated fruit crops world‐wide, and apple yield benefits from pollination by insects. The global decline in wild pollinator populations raises concern about the adequacy of pollination services in apple production. Here, we present a global meta‐analysis of pollination in apple. We assembled from the literature a dataset comprising results of 48 studies across five continents on fruit set and seed set in apple with insect pollination, artificial pollination and pollinator exclusion, and analysed the effects of explanatory factors such as variety and continent. Fruit set was on average 41% lower with open pollination than with artificial pollination, while seed set was 20% lower. These pollination deficits varied across continents and cultivars. Pollination deficits for fruit set were greatest in Asia (63%) followed by Europe (30%), whereas pollination deficits for seed set were greatest in Asia (47%) and South America (40%). Important differences in pollination deficit were also identified between cultivars but these differences were confounded with continent effects. Fruit set and seed set were 71% and 62% higher, respectively, when insects had open access to flowers than when they were artificially excluded, while results varied among cultivars. Synthesis and applications. Globally, there are substantial contributions of pollinators to fruit set and seed set in apple, as well as considerable limitations in apple pollination services, particularly in Asia, Europe and South America. Several management strategies could be applied to reduce the pollination deficits in apple production: (1) conserving wild bees and enhancing their abundance and diversity, (2) using managed bees for pollination, (3) using varieties with low pollinator dependency and/or (4) artificial pollination. These strategies should be tailored to the regional situation, considering the potential of landscapes for restoring wild pollinators, the acceptability of cultivated varieties for available pollinators, the acceptance in the market of self‐compatible varieties and the costs of management, such as artificial pollination, pollinator conservation, beekeeping and planting self‐compatible varieties. Conservation of wild pollinators is preferred in regions with sufficient potential for wild pollinators as it contributes to biodiversity conservation and improves pollination in both crops and wild plants.