Abstract:
Strychnos henningsii is a threatened and endangered medicinal plant species in Kenya. It is highly over-exploited for medicinal purposes, which has resulted in its decline in the natural habitat. For instance, it has been reported as disappearing in Ukambani areas in Kenya. A study on ethnobotany of this species reported that the species was obtained with difficulties in the study areas. Recently, Neem Foundation in Kenya reported that this species is important for malaria treatment. Therefore, this species is a serious case for conservation. The main objective of this study is to model the potential suitable habitats for growth and reintroduction of this species which can be targeted for its conservation. The use of species distribution models has gained popularity in biological sciences. These tools find use in predicting species distribution across a given area of study. The maximum entropy (or MaxEnt) distribution model was used for predicting potential a suitable habitat for S. henningsii. Therefore, field-collected co-ordinates of
International Journal of Innovative Research and Knowledge ISSN-2213-1356
www.ijirk.com Page 62
270 presence data locations of this species were used. Additionally, environmental data downloaded from the WorldClim data portal were also used. MaxEnt was then run using default settings with 75% of the locations being used for the training and the remaining 25% for the testing of the model. It generated a map of predicted suitable habitat of a species on the scale from 0 to 1. The lowest suitable areas represented by 0, and 1 representing the highest suitable areas. The results indicated that the area under the curve (AUC) for the receiver operating characteristic (ROC) analyses measured at all possible threshold values for training and test data were 0.986 and 0.983 respectfully. These values were close to 1 thereby showing that the model performed better than random and therefore points to the accuracy of the model in prediction. The areas identified for growth and reintroduction of these species were Kilifi, Kwale, Taita Taveta Mt. Kilimanjaro Game Reserve (coastal regions), Maasai Mara Game Reserve, Marigat, Maralal, Baragoi, Marsabit and Huri Hills (dry land areas in Kenya). These areas can be used to develop S. henningsii demonstration plots. People living within these niches can also be encouraged to adopt the species for agroforestry in order to conserve this important plant species.
