Increasing atmospheric CO2 concentrations correlate with declining nutritional status of European forests
Josep Peñuelas, Marcos Fernández‐Martínez, Helena Vallicrosa, Joan Maspons, Paolo Zuccarini, Jofre Carnicer, Tanja Sanders, Inken Krüger, Michael Obersteiner, Ivan A. Janssens, Philippe Ciais, Jordi Sardans
Abstract
Abstract The drivers of global change, including increases in atmospheric CO 2 concentrations, N and S deposition, and climate change, likely affect the nutritional status of forests. Here we show forest foliar concentrations of N, P, K, S and Mg decreased significantly in Europe by 5%, 11%, 8%, 6% and 7%, respectively during the last three decades. The decrease in nutritional status was especially large in Mediterranean and temperate forests. Increasing atmospheric CO 2 concentration was well correlated with the decreases in N, P, K, Mg, S concentrations and the increase of N:P ratio. Regional analyses indicated that increases in some foliar nutrient concentrations such as N, S and Ca in northern Europe occurred associated with increasingly favourable conditions of mean annual precipitation and temperature. Crucial changes in forest health, structure, functioning and services, including negative feedbacks on C capture can be expected if these trends are not reversed.