Maximum entropy model trained to estimate probability to host trees taller then 70 m based on environmental factors

Focusing only on the tallest trees - those over 70 m in height – we built an environmental envelope model to assess the conditions which allow them to occur. We employed the maximum entropy approach (MaxEnt) commonly applied to modelling species geographic distributions with presence-only data to discriminate suitable versus unsuitable areas for the species. We initially considered a total of 18 environmental variables: (1) fraction of absorbed photosynthetically active radiation (FAPAR; in %); (2) elevation above sea level (Elevation; in m);  (3) the component of the horizontal wind towards east, i.e. zonal velocity (u-speed ; in m s^-1); (4) the component of the horizontal wind towards north, i.e. meridional velocity (v-speed ; in m s^-1); (5) the number of days not affected by cloud cover (clear days; in days yr^-1); (6) the number of days with precipitation above 20 mm (days > 20mm; in days yr^-1 ); (7) lightning frequency (flashes rate); (8) annual precipitation (in mm); (9) potential evapotranspiration (in mm); (10) coefficient of variation of precipitation (precipitation seasonality; in %); (11) amount of precipitation on the wettest month (precip. wettest; in mm); (12) mean annual temperature (in °C); (13)  standard deviation of temperature (temp. seasonality; in °C); (14) annual maximum temperature (in °C); (15) soil clay content (in %); and (16) soil water content (in %).