<i>Prunus Spinosa</i> L. In Peri-Urban Environments Under Climate Change Conditions: Vulnerability and Adaptability

Summary This study aims to analyze the impact of climatic variables on the fruiting of blackthorn (Prunus spinosa L.), a species which serves as both a food source and a habitat, offering birds shelter and providing other species with refuge from predators. Accordingly, blackthorn fruiting was recorded through field research in the peri-urban green infrastructure of Belgrade over 18 consecutive years. Urban edges are often the sites of expanding artificial surfaces, habitat fragmentation, and complex land-use transitions, including agricultural intensification and abandonment, which collectively increase pressures on residual semi-natural ecosystems. The integration of floristic sampling, phenological observations, landscape measures, and climatic variables allowed for an exploration of landscapes where blackthorn is successfully incorporated into semi-natural ecosystem remnants within a peri-urban context. The results obtained indicate that the phenological patterns of blackthorn, in response to climate change, demonstrate both adaptability and vulnerability to extreme climatic events during the flowering phase. In 2024, flowering began 6 days earlier than the earliest recorded start date and 43 days earlier than the latest start recorded over the previous 17 years. Regarding the fruiting (phonological) pattern, the average fruit maturation period was 288 days, while in 2024 it occurred 61 days earlier. The statistical significance of earlier fruit maturation and reduced accumulated heat requirements for fruit ripening was confirmed, revealing that as temperatures rise, key phenological events occur earlier with reduced heat accumulation, indicating a dependency on climatic parameters. Understanding the mechanism of phenological patterns is crucial for promoting effective environmental management practices and biodiversity conservation. The study also contributes to the potential application of its findings in designing green spaces in other peri-urban regions, supporting the sustainable development of complex peripheral landscapes by integrating blackthorn into green infrastructure planning.