Physiological Performance of Beech (Fagus sylvatica L.) at its Southeastern Distribution Limit in Europe: Seasonal Changes in Nitrogen, Carbon and Water Balance

: To assess the physiological performance of drought-sensitive European beech (Fagus sylvatica L.) under the dry Mediterranean climate prevailing at its southeastern distribution limit in Europe, we analyzed seasonal changes in carbon, nitrogen and water balance of naturally grown adult trees. We determined the foliar C and N contents, δ13C and δ18O signatures, total soluble non-protein nitrogen compounds (TSNN) in xylem, leaves, and phloem, as...