Seasonal Nutrient Resorption and Lignin Change in leaves of Turkey Oak on Northern and Southern Slope Aspects

Nutrient resorption is a critical factor for nutrient use strategies developed by plants. Especially nitrogen (N) and phosphorus (P) are the most essential reabsorbed nutrient elements. The leaves' N and P concentrations are closely related to foliar lignin contents. The study aimed to investigate the effects of northern and southern slope aspects on the foliar nutrient resorption in the Mediterranean species of Turkey oak (Quercus cerris var. cerris). The relationships among selected leaf traits, foliar nutrient resorption of N and P, the seasonal lignin change, and the soil traits were analyzed. A principal component analysis was performed to interpret the effect of soil properties on foliar N, P, and lignin concentrations. N resorption efficiency (78.84%) was higher on the northern slope. P resorption efficiency (53.87%) and seasonal lignin change (69.87) were higher on the southern slope. As a result, the slope aspect affects the foliar N, P, and lignin concentrations. Also, foliar lignin concentration was negatively correlated with N resorption efficiency and positively correlated with P resorption efficiency.