Resorption and macroelement changes of some woody taxa in Firtina Valley along with altitudinal gradient

In this study, N, C, S and P dynamics, N and P resorption efficiency (RE) and proficiency (RP), SLA (Specific Leaf Area), LMA (Leaf Mass per Area) and soil parametres were investigated in Carpinus betulus, Castanea sativa, Fagus orientalis, Tilia rubra subsp. caucasica, Quercus pontica and Betula medwediewii taxa occurring in Fırtına Valley (Rize) along with altitudinal gradient. For this purpose, localities were selected from three different elevations for each taxon from areas where taxa have occured throughout the Fırtına Valley. The leaf and soil samples were taken regularly from May to October each month from these localities. The N, C, and S contents were determined by Dumas method and P concentration by spectrophotometrically. Soil nitrogen, phosphorus, potassium, pH, soil organic matter and carbon analyzes were measured. N, C, S, P nutrient dynamics, N-RE, N-RP, P-RE, P-RP, SLA and LMA and soil values in the taxa showed significant differences in terms of months and localities. In general, the N, C, S and P dynamics of all taxa reached the highest value in August and were the lowest in October. Nutrient dynamics, N and P resorption efficiency and proficiency, SLA, LMA and soil values of the taxa varied along with the altitudinal gradient. N-RE and P-RE values of Betula medwediewii were high as compared to the other deciduous species while N-RE and P-RE values of the other taxa were within normal limits. The highest N and P resorption was determined in Betula medwediewii, the lowest N and P resorption was determined in Tilia rubra subsp. caucasica among all taxa. Although N-RP values of all taxa (except for Quercus pontica) were within the declared limits, P-RP values of all taxa were high. SLA values of taxa were high during the senescence period and low in the middle of the growth season. LMA values were high in the middle of the growth season and low in the senescence period. The soil properties of all taxa showed significant differences according to both altitude and months.