CLIMATE CHANGE IMPACTS ON THE DISTRIBUTION OF STIPA TENACISSIMA L. ECOSYSTEMS IN NORTH AFRICAN ARID ZONE - A CASE STUDY IN TUNISIA

Stipa tenacissima L. (Alfa grass) is an important perennial grass species in Tunisia and Northern Africa which dominates wide arid ecosystems offering multiple services. The focus of this study is to explore how the distribution of suitable habitat for Stipa tenacissima, might shift under climate change. To investigate the potential effects of climate change on the target species we used Maxent modeling algorithm for two representative concentration pathways (RCPs) lower emission scenario (RCP 2.6) and higher emission (RCP 8.5) climate forcing scenarios in 2050 and 2070. Results of the analysis showed a negative impact of climate change on the S. tenacissima ecosystem. There is a decrease in suitable habitat for alfa through time and across space with an increase in greenhouse gas. Suitable habitat was projected to decline through time from 64% to 70% by 2050 for RCP 2.6 and RCP 8.5 respectively and from 86% to 92% by 2070 for RCP 2.6 and RCP 8.5 comparatively to the current state. Across space, when projecting model into the future, the area of predicted suitable habitat of Tunisian alfa grass would dramatically reduce in the central area, and disappear from the Southern area. Therefore, global warming associated with climate change by the years 2050 and 2070 might affect the suitable bioclimatic habitat of S. tenacissima with a severe loss of habitat suitability.