MODELLING SPATIO-TEMPORAL DISTRIBUTION OF Prosopis juliflora UNDER PREDICTED CLIMATE CHANGE IN MARIGAT SUB-COUNTY, KENYA

Abstract

Prosopis juliflora is an invasive species that has caused adverse ecological, social and economic impacts in Kenya. Climate change is anticipated to aggravate the spread and invasion of this species. This is now raising concerns because further expansion of this species will worsen its negative impacts on the livelihoods of the adjacent communities, and on the ecological integrity of the invaded areas. However, there is limited understanding and knowledge on the influence of climate change on the distribution of P. juliflora. Therefore, the aim of this study was to examine the current and future distribution of P. juliflora under different climate change scenarios in Marigat sub-county; to better influence appropriate decision-making processes on the management of this invasive species. In this study, MaxEnt model was used to predict the current and future distribution of P.juliflora under different climate change scenarios. The results indicated that mean annual temperature (Bio1), mean annual rainfall (Bio12), elevation and moisture index moist quarter (Mimq)were the main factors that determined the distribution of this species. Further, climate change is expected to increase the potentially suitable areas for this species across all the future climate change scenarios. The greatest increase is experienced in 2055 under RCP 8.5 and 2085 under RCP 8.5 with an average range increase of 34.5% (25942.73 hectares) and 24.3% (23991.24 hectares) respectively. The current coverage has also increased from 18,792 hectares in 2016 to 19293.70 hectares in 2020. With the current cover, P. juliflora has already caused significant negative impacts in this study area. Further expansion would worsen the problem leading to more decline in the community livelihoods and damage to the environment. Therefore, urgent, appropriate, effective and efficient P. juliflora management measures need to be urgently taken to counter its spread. For instance, stakeholders both at the county and national government should take coordinated actions and invest in early detection and monitoring programs, mapping of areas of higher risk of invasion and also put in place integrated approaches to combat further expansion, eradicate or minimize the negative impacts of the species