1 The relict ecosystem of Gymnosporia senegalensis (Lam.) Loes. in an agricultural 2 plastic sea: past, present and future scenarios 3 4 5 18 19 20 21 22 23 Acknowledgements 24 This study has been made possible through the projects 'CEIJ-012 Integrated study of 25 coastal sands vegetation (AREVEG)' and 'CEIJ-009 Integrated study of coastal sands 26 vegetation (AREVEG II)' sponsored by CEI·MAR; 'Assessment, Monitoring and 27 Applied Scientific Research for Ecological Restoration of Gypsum Mining 28 Concessions (Majadas Viejas and Marylen) and Spreading of Results 29 (ECORESGYP)' sponsored by the company EXPLOTACIONES RÍO DE AGUAS 30 S.L. (TORRALBA GROUP) and 'Provision of services, monitoring and evaluation of31 the environmental restoration of the mining concessions Los Yesares, María Morales 32 and El Cigarrón' sponsored by the company Saint Gobain Placo Iberica S.A. 33 34 Abstract 35 Gymnosporia senegalensis is a shrub belonging to the Celastraceae family, 36 which is native to tropical savannahs. Its only European populations are distributed 37 discontinuously along the south-eastern coast of the Iberian Peninsula, forming plant 38 communities with great ecological value, unique in Europe. As it is an endangered 39 species that makes up plant communities with great palaeoecological significance, the 40 development of species distribution models is of major interest under different 41 climatic scenarios, past, present and future, based on the fact that the climate could 42 play a relevant role in the distribution of this species as well as in the conformation of 43 the communities in which it is integrated. Palaeoecological models were generated for 44 the Maximum Interglacial, Last Maximum Glacial and Middle Holocene periods. The 45 results obtained showed that the widest distribution of this species, and the maximum 46 suitability of its habitat, occurred during the Last Glacial Maximum, when the 47 temperatures of the peninsular southeast were not as contrasting as those of the rest of 48 the European continent and were favored by higher rainfall. Under these conditions, 49 large territories could act as shelters during the glacial period, a hypothesis reflected 50 in the model's results for this period, which exhibit a further expansion of G. 51 senegalensis' ecological niche. The future projection of models in around 2070, for 52 four Representative Concentration Pathway (RCP) according to the fifth report of the 53 Intergovernmental Panel on Climate Change IPCC, showed that the most favorable 54 areas for this species would be Campo de Dalias (southern portion of Almeria 55 province) as it presents the bioclimatic characteristics of greater adjustment to G. 56 senegalensis' ecological niche model. Currently, these areas are almost totally 57 destroyed and heavily altered by intensive agriculture under plastic, also causing a 58 severe fragmentation of the habitat, which implies a prospective extinction scenario in 59 the near future. 60 61 Introduction 62 Gymnosporia senegalensis (Lam.) Loes. [=Maytenus s...