DETERMINING CLIMATIC AND SOIL FACTORS TRIGGERING THE INVASION OF Prosopis juliflora (Sw.) DC IN AFAR REGION OF ETHIOPIA

Abstract

In Ethiopia, Invasive Alien Species (IAS) and their related ecological, social, and economic impacts are increasing. The expansion rate of P. juliflora (Mesquite) brought economic, social and ecological problems in Afar region. The intension of the present study was to map the spatial and temporal distributions of P. juliflora and examine its related climatic and soil triggers in Afar region, Ethiopia. Mapping the temporal and spatial distributions and quantifying the invaded areas was carried out using geospatial techniques. The results showed that during the period 1985 to 2016, P. juliflora expands by 136 km2 annually. Generalized Linear Model (GLM) was applied to examine the driving climatic and soil factors on field samples that revealed significant influences of climate and soil variabilities on the temporal and spatial distributions of P. juliflora in the region (R2 =0.79; DF=10; P<0.01%). In comparison Elevation, soil moisture content, temperature, soil pH, and bulk density are top determinants for Mesquite distributions in Afar. P. juliflora is positively correlated to temperature and rainfall, and negatively correlated to elevation, bulk density, soil moisture contents, and soil reaction (pH). While soil organic carbon content and soil texture relatively do not show consistent trends with P. juliflora distributions. The results of the study are helpful in making and / or implementing policies and strategies of environmental and biodiversity managements. The study recommends for integrating IAS management and strategies to climate change adaptation and soil conservation activities as well as suggests future studies to include ecological triggers of IAS.