Impact of Biological Invasion on Floristic Composition in An Indian Dry Tropical Urban Region of India

Biological invasions are key contributor to global environmental change, leading to the depletion of native biodiversity and functional changes in ecosystem. Anthropogenic activities add to the aggravation caused by these intrusions. This study was aimed to investigate the invasion trends of alien flora within a dry tropical region of India i. e. region across Meerut University Campus and surrounding area, which is a well intruded area located amidst the rapidly urbanizing districts of Uttar Pradesh, India. Extensive site surveys were conducted in the study region from 2019 to 2022, resulting in the compilation of a species list which was derived from recorded flora and existing literature. Each species was classified based on its nativity, life form and habit. Out of 111 plant species spread across 37 families, 84.49% were identified as alien, while only 15.51% were found native. The highest proportion of alien flora originated from American biogeographic regions (36.06%), followed by Asian (10.81%), European (9.91%), African (5.41%), Australian (3.61%) and 21% of mixed origins. Dominant families included Poaceae, Fabaceae, Asteraceae, Malvaceae, Cyperaceae, and Amaranthaceae; collectively constituting to 58.31% of the total flora. Herbaceous species were most prevalent, accounting for 85.58%, followed by shrubs (9.01%), climbers (3.61%) and trees (1.81%). Further annual life form was more dominant (65.76%), followed by perennial (26.12%) and biennial (1.81%). Increase in perennial invaders shows the progressing threat to native species. The findings highlight an increasing trend in the intrusion of alien flora, predominantly from American, Asian and European biogeographic origins, into the studied region. These results underscore the need for effective management strategies to mitigate the naturalization, colonization, and invasion of alien weeds in urban areas where native species are already under threat and undergone many alterations, particularly within rapidly urbanizing anthropo - ecosystems in Indian dry tropics.