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

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 www.scholink.org/ojs/index.php/rhs Research in Health Science Vol. 6, No. 2, 2021 40 Published by SCHOLINK INC. 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.


Introduction
Medicinal as well as aromatic plants are seen globally as raw materials in the pharmaceutical and traditional health sectors (Phondani, Maikhuri, & Saxena, 2014). It has been observed that over 85% of traditional herbal medications globally are derived from medicinal plants (Phondani, Maikhuri, & Saxena, 2014). Such is seen in the Indian pharmaceutical sector where out of the 280 medicinal plants being used, 175 are found in the Indian Himalayan Region (Kumar, 2015). Studies from Iran showed that there are 8,000 medicinal plants growing in the wild and Geographical Information System (GIS) has been leveraged upon to map these to strengthen operationalization of policies and plans towards improving livelihoods for rural communities (Mashayekhan, Reza, Jidian, Jalilvand, Gholami, & Teimouri, 2016). Most of these medicinal plants are now being threatened due to urbanization, land clearing for farming and overharvesting 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. Nonetheless, best practices on cultivation, and sustainable harvesting could be leveraged on as strategies for sustainable livelihood in rural communities. Some countries like Canada under the Medicinal Plant Project (Chowdhury, Koike, Muhammed, Halim, Saha, & Kobayashi, 2009).
This study attempted to present systematic biodiversity, ethno-botanical survey and geospatial analysis of indigenous medicinal plant species used for management of malaria and other associated illnesses and its implication on conservation management in rural Kwara State, Nigeria.

Study Area
Our study area is located in Moro local government area (LGA) of Kwara state, Nigeria. Kwara state is

GIS Operation for Land Cover Mapping
We subset the geographic extent of the study area using both the settlement point data and the administrative shape file at ward level in ArcGIS 10.2 ( Figure 1). The 2019 Sentinel satellite images of the Ilorin-Igbeti scenes at 20 m spatial resolution was obtained and downloaded from web portal of Copernicus project (https://scihub.copernicus.eu).
Raster processing was performed by cropping the study area extent from the larger satellite images.
Image enhancement and band combinations were performed to extract land cover features such as vegetation water bodies and settlements. All the satellite images were co-registered to the same study area shape file to give similar spatial dimension. As shown in Figures 2 and 3, vegetation index analysis was performed using soil adjusted vegetation index (SAVI) as proposed by Huete (1988) to distinguish gradient of plant cover and minimize the effect of soil background on vegetation signal in the landscape. We set our soil adjustment L factor to 0.5 given the semi forest nature of the study area.

Figure 3. Soil Adjusted Vegetation Index
The Nearest Neighbour Analysis was carried out to determine the spatial pattern of observed medicinal plants in the study area. NNA is a statistical model used to determine the probability of finding a point within a radius around one point follows a Poisson distribution when sampled from a population of points on a plane (Clark & Evans, 1954). It is indexed from 0 being clustered to 1 being random and 2.15 being regular in spatial pattern.

Statistical Analysis
Each study questionnaire involved seventy-six constructs/variables on the entire subject matter. Among these variables, fifty-one (51) are quantitative variables while the remaining twenty-five (25) constitute qualitative variables. For the nine respondents, the study involved a total of 459 observations from qualitative variables among which 42 were missing due to non-responses. We completed cases for the data by automatically replacing the missing entries in a reliable data-adaptive way using multivariate imputation by chained equation technique, package of the version 3.6.1 of the R software for statistical computing and graphics (R Core Team, 2019).

Ethical Clearance
All aspects of the study were approved by Kwara State University Research Committee and Ethical Review Board. Verbal and written Informed consent was obtained from the traditional healers used as respondents through community leaders and magajis'. They were assured of voluntary participation, confidentiality of their responses and the opportunity to withdraw at any time without prejudice in line with the Helsinki Declaration was emphasized (World Medical Association, 2001).

Results
The study found twenty-one (21) different ethno-medicinal plants used in different forms for management of malaria and other associated allied illnesses in the rural communities (Table 1).  Common illnesses identified include malaria, typhoid fever, skin rashes, cough, diarrhea, cholera, measles, convulsion, diuretics and others in the settlements. However, data evidence revealed that all (100%) of the respondents are aware of malaria in their practice and experience with ethno-medicinal plants and herbs. Data evidences also showed that majority of the traditional healers combine the identified medicinal plants in the treatment of malaria as presented (Table 3). Some of the combinations therapies are presented in table 3 while those acclaimed to be most effective for treatment of both acute uncomplicated and severe malaria are listed in Table 4 respectively.  Six classes of land use land cover (LULC) were identified as follows: Water bodies, river valley, savanna woodland, degraded woodland, grassland and settlements cluster with the associated medicinal plants (Table 6).  . This further support the aim of this study which seeks to leverage conservation of medicinal plants for treating malaria in their natural habitats. The random spatial pattern confirms that these plants have not yet been affected by anthropogenic activities and hence they need to be conserved there in the wild.

Conclusion
Out of the nine identified traditional healers in the community, all nine claimed to have used at least one or some in combinations of these plants for treatment of malaria. It could be seen that all identified species of medicinal plants when mapped had statistically random distribution proving their growth being in the wild and being influenced by nature. With increasing reliance on traditional medicine, there is a 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. Urbanization due to increasing sphere of influence of KWASU in the area should also be monitored and proper urban planning initiatives incorporated to ensure cultivation of these plants are incorporated into the greening efforts of the Kwara state government in this area.

Competing interests
No conflict of interest associated with this work.

Contribution of Authors
We declare that this work was done by the authors named in this article and all liabilities pertaining to claims relating to the content of this article will be borne by the authors.