Wood property and leaf habit structured leaf resource acquisition strategies across 30 subtropical urban tree species

Abstract

Urban stressors may drive plant community homogenization through environmental filtering, yet the convergence of survival strategies across different urban plant types remains unclear, limiting a deeper understanding of urban forest management. We investigated whether tree species differing in key functional trait differences (such as wood properties and leaf habits) exhibit convergent leaf-level resource acquisition strategies in urban environments, and how these changes influence their survival strategies. We assessed eight leaf economic traits in 30 urban woody species to test the differentiation across evergreen diffuse-porous, deciduous diffuse-porous and deciduous ring-porous species. We found that evergreen diffuse-porous species favored a slow-return strategy with high leaf mass per area (LMA), carbon-to-nitrogen ratio (C:N), and leaf carbon content (LCC), while deciduous ring-porous species adopt a fast-return strategy, with lower LMA and higher nitrogen content (LNC) and photosynthetic rate (A_mass). Deciduous diffuse-porous species occupied an intermediate position, balancing resource acquisition and conservation. The trade-off between LNC and LMA revealed that deciduous ring-porous species had heightened sensitivity of A_mass to structural investment, indicating reliance on rapid resource acquisition in urban environments. In contrast, evergreen diffuse-porous species relied more on LNC for photosynthetic efficiency, with greater structural investment reflecting a conservative strategy. Differences in wood properties further amplified these strategic divergences, particularly in the trade-off between LNC and LMA. Our results revealed diverse resource acquisition strategies among species with distinct wood and leaf types. For future urban forest management, species selection should consider not only the evergreen-deciduous ratio but also wood property to enhance ecosystem resilience and stability.