The past, current, and future distribution modeling of four water lilies (Nymphaea) in Africa indicates varying suitable habitats and distribution in climate change

Abstract

Mapping and modeling suitable habitat and distribution of aquatic species is important to help assess the impact of factors such as climate change in affecting the shift, decline, or expansion of species habitat ranges. In Africa, the distribution of water lily (Nymphaea) species is geographically varied and the habitats suitable for individual species are prone to effects of global warming, though only limited conservation measures have been taken to date in aquatic environments. In this study, four widely distributed water lily species (N. nouchali, N. micrantha, N. lotus, and N. heudelotii) were modeled using MaxEnt which highlighted the individual species’ suitable climatic distribution. The current distribution indicates a partial distribution of N. nouchali in West Africa unlike N. micrantha, N. lotus, and, N. heudelotii. Nymphaea lotus displays wider distribution in West, East, and parts of South African countries including their coastlines compared to all other species. Nymphaea nouchali indicates dense distribution in countries South of Africa while N. micrantha and N. heudelotii in West African countries. Greater habitat changes were noticed between the future and the past projection due to limited range expansion in 2.6, 4.5, and 8.5 (2050) Representative Concentration Pathways (RCPs) in almost all species. The species’ suitable habitat distribution was mainly influenced by nine variables, mostly the temperature and precipitation variables. This study provides projections of future climatic scenarios potentially influencing the distribution of Nymphaea species in Africa, which may be useful for the ongoing conservation and management of these plants especially in areas loosing suitable climatic conditions.