Abstract:
Gallery forests in Central Black Sea Region are dominated by Platanus orientalis L. The studies were performed in four sites (Mert River, Adalar, Kurupelit and Taflan Regions) located in V-shaped river valleys and differing with soil conditions. Nutrient concentrations were measured in green and senescent leaves in selected sympatric tree species. Foliar nutrient resorption efficiency (RE; as the ratio of the resorbed amounts of nutrient losses during the leaf senescence to its prior amount deposited in the leaves) and proficiency (RP; the level to which nutrient content per unit leaf mass, Mg 9, has been reduced in senescent leaves) were examined in several sympatric species. The high nitrogen resorption efficiency (N-RE) (62%) were found in Hedera helix L., while the lowest (40%) - in Salix alba L. The phosphorus resorption efficiency (P-RE) ranged between 35% (Rubus discolor Weithe and Nees) and 50% (S. alba) and that of potassium (K-RE) ranged between 49% (S. alba) and 62% (Robinia pseudoacacia L.). The different trend was observed in the values of proficiency (RP). The high nitrogen resorption proficiency (N-RP) ranged between 10 mg g(-1) (Clematis vitalba L.) and 18 mg g(-1) (R. discolor). The high phosphorus resorption proficiency (P-RP) was found in R. discolor (0.5 mg g(-1)) similar to N-RP. The lowest P-RP was found in R. pseudoacacia (0.3 mg g(-1)) like K-RP (5 mg g(-1)). The high K-RP (10 mg g(-1)) was found in H. helix. There is no significant difference between four study sites. Soil N, P and organic matter concentrations were significantly correlated with green-leaf N, P and K concentrations. Significant correlations were also found between K-RP and soil nutrient concentrations and soil moisture. However, no significant correlations were found among green-leaf nutrient concentrations, RE, RP and soil nutrient concentrations and moisture.