8. Comparative Biodiversity Assessment of Weed Species in Monocropping Plantations of University of Ilorin, Nigeria

Abstract

The present study investigates the weed species diversity in four plantations of university of Ilorin, Ilorin, Nigeria using quadrat method. The survey revealed two major life cycles (annual and perennial) and recorded a total of 88 weed species belonging to 32 families. Four species (Azadirachta indica, Daniellia oliveri, Desmodium tortuosum, and Tridax procumbens) were common in all the surveyed plantations while the family Fabaceae was the most dominant. The abundant weed species analysis showed a high importance value index and were more adapted to the plantations. Diversity analysis revealed high species richness in the sugarcane plantation. The non-canopy nature of the plantation, soil structure as well as ability to coexist with many other species may underscore the reasons for this pattern of diversity. The evenness and similarity indices between and across the plantations were generally low, thus, indicating varying diversity. As a result of the recorded variation in weed composition between and across the plantations, the study has provided an insight on the pattern of weed diversity in the studied plantations. The study recommended that the most abundant weed species populations be checked for the plantations to thrive. Finally, there is an urgent need to conserve weed species that are not only rare in abundance but also showed great social and economic values.