Dr. Nidhi Shubhanand
Department of Botany
M. K. R. Government Degree College, Ghaziabad, Uttar Pradesh- 201003
Abstract
The green city spaces are developed to support biodiversity, deliver ecosystem services, and enhance human wellbeing in rapidly urbanising areas. This review focuses on how urban plant diversity and landscape design add value to the environment and the respective roles of native and exotic species in sustainable greenspace planning. Based on landscape ecology, invasion biology, ecosystemservice assessments, and urban design studies, this paper demonstrates that plant origin strongly impacts spatial patterns like patch size, connectivity, and surrounding land use which in turn influence biodiversity and ecosystem function. Studies show that native plants supports greater native animal diversity and stronger food chains. Carefully selected, noninvasive exotic species can balance native flora by tolerating harsh urban conditions by adding diversity to structure of the ecosystem. However, invasive alien plants increase the greenness in surroundings but also lower the native species richness and leads to biotic homogenisation. A case study of Delhi-NCR shows that in rapidly urbanising cities rich native species diversity, widespread exotic species, and invasive species coexist under intense development pressure. It could be concluded that sustainable urban planning should focus on native plant species with judicial use of exotic species for multiscale landscape planning. Multifunctional ecosystem can be developed by combining robust native flora, noninvasive exotics and active invasivespecies control.
Key Words: Urban landscape, Homogenisation, Native and Exotic species, Biodiversity