Effects of abiotic and anthropogenic factors on the spatial distribution of Quercus faginea

11 12 Species distribution is usually explained by abiotic factors, particularly, climatic variables which 13 are often considered as the most important drivers of species distribution. Nevertheless, when 14 investigating the underlying causality in species distribution, the importance of those factors 15 together with the role of anthropogenic factors (land-use variables) must be considered. 16 Particularly in the Mediterranean basin where natural ecosystems underwent important 17 transformations due to anthropogenic pressure in the territory. In this work we studied the effects 18 of abiotic and anthropogenic factors on Quercus faginea distribution identifying the key factors 19 that shape its distribution in the Spanish Central Pyrenees. Data on presence-absence of Q. 20 faginea species, abiotic variables and anthropogenic variables were derived by GIS from digital 21 sources and aerial photographs. We used Bayesian model averaging to identify the key factors 22 that affect the spatial distribution of Q. faginea. Than Then we applied hierarchical partitioning 23 to estimate the relative importance of each key factor. In the Spanish Central Pyrenees, on a 24 broad scale, abiotic variables, i.e. climate and lithology, were identified as underlying factors that 25 shape the spatial distribution of Q. faginea. The presence of recently introduced plantations and 26 previous livestock pressure had a negative effect on Q. faginea distribution; which represent the 27 anthropogenic disturbance effect on this species. This study indicated that in this mountain area 28 and at our regional scale, although abiotic factors have a great importance in explaining the 29 underlying causality in Q. faginea distribution, anthropogenic factors can not be neglected. 30