<p>Urban green spaces (UGS) play a critical role in enhancing biodiversity, mitigating environmental stressors, and promoting ecosystem resilience within highly urbanized areas. However, rapid urbanization in megacities such as Metropolitan Manila has led to the loss and fragmentation of these ecological frontiers, highlighting the urgent need to assess their ecological functions. This study investigates the plant functional diversity and ecological dynamics of two key urban forests in Metro Manila—Arroceros Forest Park and Las Piñas-Parañaque Wetland Park—by analyzing whole-plant and leaf trait-specific indicators to evaluate ecosystem functions and services. Functional diversity indices were employed to identify relationships among plant communities and assess how species’ functional traits influence ecosystem stability. Results indicate that while species in both urban forests exhibit similar functions, variations in functional characteristics are driven by phenotypic plasticity, habitat filtering, and ecological differentiation. These factors influence community-based functional diversity, affecting species adaptability and resilience. The study highlights the importance of maintaining high functional diversity to support ecosystem services, emphasizing the role of urban forests in mitigating environmental challenges in rapidly developing cities. Findings from this research provide valuable insights into urban conservation strategies. Additionally, it reinforces the necessity of integrating functional diversity into urban ecological planning to enhance ecosystem resilience and sustainability. Furthermore, the study highlights the potential for more comprehensive ecosystem assessments by incorporating abiotic variables and examining interactions with fauna and microbial communities that may significantly influence ecological dynamics.&#xa0;</p>