Seasonal Terpene Variability in Pinus nigra Needles from Urban and Natural Sites: Insights for Health-Related Ecosystem Services

Urbanization is increasingly limiting daily human exposure to natural forest environments, highlighting the growing importance of urban green infrastructure and nature-based solutions in supporting human health and well-being. Among the mechanisms underlying the beneficial effects of forests, biogenic volatile organic compounds (BVOCs), particularly terpenes, are recognized as key contributors due to their bioactive properties and role in cultural ecosystem services related to human well-being. This study explores the potential of urban and natural trees of Pinus nigra J. F. Arnold to serve as sources of health-relevant BVOCs by examining seasonal and spatial variability in needle terpene profiles. Needle samples were collected from trees growing in an urban park and a protected natural area across three seasons (spring, summer, and autumn), and analyzed using headspace GC/MS. The study was designed as an exploratory assessment aimed at identifying general patterns of terpene variability across contrasting environments. Across all seasons and locations, α- and β-pinene consistently dominated the terpene profile, together accounting for the majority of detected compounds, and showed no significant variation in relation to site or season. In contrast, secondary monoterpenes and sesquiterpenes exhibited greater variability, contributing to context-dependent differences between environments. Despite these variations, the overall terpene composition remained relatively stable, particularly with respect to compounds previously associated with health-related effects. These preliminary findings provide insights into the potential role of Pinus nigra within urban and natural green infrastructure associated with nature-based health-oriented practices. The observed stability of health-related terpenes suggests that urban Austrian pine trees can represent a consistent source of compounds previously associated with health-related effects, although their relevance requires further investigation involving total and individual BVOC emissions measurements and human exposure assessments.