Potential Future Changes of the Geographic Range Size of Juniperus phoenicea in Algeria based on Present and Future Climate Change Projections

Abstract

MaxEnt (Maximum Entropy), a Species Distribution Modelling (SDM) method, was applied in the current study in order to assess present and future spatial distribution of the Phoenician juniper (Juniperus phoenicea). Potential future changes in the geographic range size of J. phoenicea in Algeria was determined for the two horizons 2050 and 2070 based on CCSM4 model of the IPCC. Three types of data were used in SDM namely: 21 edaphic factors, 10 topographic parameters, and 19 climatic factors. The AUC value (Area Under Curve) scored 0.966, which showed the high performance of the MaxEnt model. The most contributing variables were: total soil carbon (22.1%), Bio14: driest month precipitation (19.2%), slope (11.1%), Bio15: seasonality of precipitation (coefficient of variation) (10.3), total soil nitrogen (7%), soil available water capacity during summer (6.3%). The presence probability map obtained shows a narrowing of the favorable area of the species by about 52.5% by the year 2070. Such a result asserts the vulnerable state of this species toward the climate change, which results in altitudinal, longitudinal and latitudinal species distribution range shift as a response reflecting the becoming of unfavorable changes of the Phoenician juniper habitats. Based on these results, it is necessary to adopt necessary planning measures for the protection and conservation of the species regarding its vulnerability to climate change.