Modeling the expansion of Prosopis juliflora and determining its optimum utilization rate to control the invasion in Afar Regional State of Ethiopia

Abstract

Prosopis juliflora is as an alien invasive tree species which is expanding at an alarming rate in the Horn of Africa region. In this paper a mathematical model is developed to estimate the rate of expansion in the Afar region of Ethiopia based on the coverage obtained with GIS analysis from the year 2000 satellite image for the region. The exponential model estimates that the tree species has been expanding at a rate of 50,000 hectares per year in the last ten years in the Afar region. The model further projects, if the tree species is used for productive uses such as energy and consumed at a rate of 90,000 hectares per year, the invaded land can be restored effectively in 15 years time. Furthermore, the model proposes that after the end of the 15 year, Prosopis can be contained within 200,000 hectares and provide 26,000 hectares of wood per annum sustainably for productive uses.