The phosphorus nutrition of European beech and Palestine oak under a future warmer and drier climate: experiments and transect studies

Temperate and Mediterranean forest productivity may increasingly be limited by shortage of phosphorus as is indicated by declining P concentrations and increasing N:P ratios in leaves and fine roots and reports on recent growth reductions that appear to be caused by P limitation. Continued high atmospheric N deposition in combination with decreased summer precipitation and increased temperature in the course of climate change are likely to result in further alterations of the P nutrition of temperate and Mediterranean forest trees in the next decades, with either negative or positive consequences for productivity. In order to enable sound predictions about the P nutrition of European beech and Palestine oak under global change, four-factorial climate chamber experiments are conducted examining the effects of P supply, soil moisture, temperature, N supply, and their interactions on various morphological and physiological parameters in beech and oak saplings. In studies in beech and oak stands along precipitation gradients in northern Germany and Israel, respectively, we test the validity of the obtained results under field conditions with mature trees in temperate and Mediterranean climates at variable P availabilities along the gradients.