Soil aeration, water deficit, nitrogen availability, acidity and temperature all contribute to shaping tree species distribution in temperate forests

AimKnowledge about suitable ecological conditions for tree species remains largely incomplete. We aim to quantify and compare suitable environmental conditions for some of the most common tree species in Europe using a modelling approach and a large array of predictors that describe the different dimensions of the environmental niche. LocationFrance. MethodsUsing a large database of 46768 plots distributed across France (550000km(2)), we compared the performance of 61 physiologically relevant predictors that describe temperature, soil nutrient supply, soil water availability and aeration at fine spatial resolution to model the distribution of 32 tree species. To allow some comparisons between species along the same gradients, the most efficient predictors were determined and used to characterize the species requirements. ResultsMean annual temperature, soil water deficit, soil pH, C/N and temporary and permanent waterlogging gave the best performances. The efficiency of species distribution models based on these six variables was comparable to models calibrated with 61 variables. For the first time, those models provide a unique quantitative framework of homogeneous information concerning the requirements for a large number of tree species. ConclusionsOur results highlight the importance of soil descriptors to shape plant distribution and allow each species to delineate areas inside the climate envelope with favourable nutritional and moisture conditions. These results emphasize a gap between existing studies on species distribution, mainly based on large-scale climatic predictors, and empirical knowledge or existing practices where soil is recognized as a main driver.