The Potential of Thunbergia spp. as a Green Facade Plant and Its Invasive Impact on Urban Biodiversity in Colombo, Sri Lanka

Abstract

The incorporation of green facades within urban architecture offers multifaceted benefits, including thermal regulation, air purification, carbon sequestration, and enhanced aesthetic value. Thunbergia spp., particularly Thunbergia grandiflora and Thunbergia fragrans, are widely utilized in tropical regions for rapid vertical greening due to their vigorous growth and dense foliage. However, the aggressive propagation and invasive potential of Thunbergia raise significant ecological concerns. This study critically examines the use of Thunbergia spp. as a green building covering plant in Colombo, Sri Lanka, with a focus on its growth performance, environmental adaptability, and potential adverse impacts on urban biodiversity. The research employs a mixed-methods approach comprising field experimentation, ecological impact assessments. The results indicate that while Thunbergia offers considerable. ecosystem services in the built environment, it poses substantial risks to native flora due to its invasive behavior. This paper concludes with evidence-based recommendations for the controlled application of Thunbergia
in urban greening initiatives.