Format: ORAL

Maria M. Ribeiro1,2,5*, Alice M. Almeida1, Natlia Roque1,2,3, Celestino Quintela-Sabars4, Maria Joo Martins5, Manuel L. Campagnolo5, Paulo Fernandez1,6

1 Polytechnic Institute of Castelo Branco, School of Agriculture, Castelo Branco, Portugal 2 CERNAS, Research Center for Natural Resources, Environment and Society, Polytechnic Institute of Castelo Branco, Castelo Branco, Portugal 3 QRURAL, Quality of Life in the Rural World – Research Unit, Polytechnic Institute of Castelo Branco, Castelo Branco, Portugal 4 GEA, Animal Ecology Group, Vigo University, Vigo, Spain 5 CEF, Forest Research Centre, TERRA Associated Laboratory, Superior Institute of Agronomy, Lisbon University, Lisbon, Portugal 6 MED – Mediterranean Institute for Agriculture, Environment and Development & CHANGE – Global Change and Sustainability Institute, Évora University, Évora, Portugal

The Mediterranean region is utterly vulnerable to global change and provoked disturbances in Mediterranean plant species distribution will be crucial for management and conservation design. Climate change impact in two well-adapted Mediterranean species, drought, and temperature-resistant, was studied (rockrose (Cistus ladanifer L.; CL) and strawberry tree (Arbutus unedo L.; AU)). The past, present, and future potential spatial distribution was unfolded, and the potential glacial refugia based on modeling, phylogeography, and fossil data was verified. Modeling was made based on real occurrences and environmental variables using machine learning and regression-based algorithms. The potential future distribution was projected for the years 2050 and 2070, considering a less and more severe climate scenario. The precipitation variables had decreasing importance in the obtained models, followed by the temperature variables, in the case of the CL, but conversely in the case of the AU, being the slope influential. For both species, the results of the Last Glacial Maximum (LGM) projection suggested the presence of refugia in the core of the Mediterranean Basin, particularly in the Iberian Peninsula (PI) southeast. Projections for the Mid-Holocene (MH) indicated increasing climatic suitability and expansion for the two species relative to the LGM. The past distribution projections modeled were congruent with the two independent approaches (fossil and genetics), validating the CL distribution modeling in the past, unlikely in the AU case, where very strong fossil signals were found in the IP borders, even in northern regions. Those species will be dramatically affected by global warming, despite drought and temperature resilience, particularly the CL. Contrarily to AU, CL northward future migration is unlikely to happen, but a westward collapse towards the Portuguese coast. The AU northern migration will depend on its ability to pace and adapt to environmental changes speed. Consequently, thermophilic Mediterranean species will probably be endangered.