Ethnobotanical Survey and Habitat Mapping of Medicinal Plants and Its Implication on Conservation Management in Rural Kwara Communities

Abstract

Background: In Nigeria, medicinal plants are now being threatened due to increased urbanization, land clearing for farming and over-harvesting from their natural habitats. As such, if such trends continue, some of these medicinal plants might increasingly become not available and in the extreme circumstance be faced with extinction.

Methods: An epidemiological descriptive field survey that employed a carefully-structured, closed-ended, interviewer-administered, paper-based questionnaire designed to capture information on the use of medicinal plants as antimalarial and for management of other associated illnesses. We also employed Global Positioning System (Garmin etrex 75) to captures the geo-coordinates of previously identified medicinal plants across the footpath transect at 20 m intervals. A total of twenty-one (21) medicinal plant species were surveyed across five communities with varying numbers per locations.

Results: Out of the nine (9) identified traditional healers across the communities, all claimed to have used at least one or combinations of these plants for treatment of malaria. An image classification performed through land cover land use map of the study area revealed six classes: swamp /water bodies, river valley, savanna woodland, degraded woodland, grassland and settlements cluster. Most threatened species such as Aristolochia ringes, Mucuna prurins, Azadirachta indica, Kigelia africana, Citrus limon, Ludwigia suffruticosa, Parkia biglobosa, and Picralima nitida are those found in Malete KWASU campus axis in the degraded woodland and settlement cluster classes. This is due to the high level of forest destruction in the area as a result of growing student population and massive constructions of students’ hostel. We reported that about 60% of original plant cover has been lost between 2005 and 2015. It was observed that availability of surface water bodies played a crucial role in influencing the distribution of identified medicinal plants. The nearest neighbour analysis gave a nearest neighbour index of 0.695 at p=0.000003 and z-score of -4.70314. This shows that the observed random distribution of medicinal plants in the study area was statistically significant. It has been observed that random patterns are usually associated with natural occurrences. The random spatial pattern confirms that these plants have not yet been affected by anthropogenic activities and hence need to be conserved there in the wild.

Conclusion: There is need to leverage on conservation of medicinal plants for treating malaria in their natural habitats. Also, the need to ensure sustainable harvesting and other socio-ecological process to ensure these are not threatened to the extreme case of extinction in these communities. In the view of the above, we recommend that KWASU-Malete campus axis be monitored, proper urban planning initiatives implemented and ensure cultivation and preservation of these plants are incorporated into the greening efforts of the Kwara state government in this area.