Diversity, Distribution and Habitat Suitability Assessment of Solanum Species of the Leptostemonum Clade in Uganda

Abstract

The diversity and distribution of Solanum species of the Leptostemonum clade in Uganda was updated based on field surveys, herbarium collections and literature. Distribution maps were generated using ArcMap software and Spatial Distribution Models generated using maximum entropy software (version 3.3.3). Predictions were based on five environmental variables, namely: temperature, rainfall, slope, soil and land use/cover. Model evaluations were based on Area Under Curve. Jack knife test assessed the importance of each environmental variable in predicting species occurrence. Twenty-one species were recorded with Solanum chrysotrichum as a new record for Uganda. The highest species richness was recorded in southwestern Uganda. Karamoja had unique diversity with four species restricted to the region, thus: S. forskalii, S. lanzae, S. coagulans and S. hastifolium. Most of the species occur in disturbed habitats in the land use/cover areas defined as croplands, tree cover and grasslands. Temperature and rainfall were the most useful variables in predicting occurrence of Solanum species. Karamoja and South western sub regions are hotspots for conservation of the spiny Solanum species. Periodic field surveys should be carried out in order to monitor changes in the occurrence of Solanum particularly in the identified hotspots.