Impact of harvesting methods and forest floor displacement on nutrient stock of Scots pine ecosystems in the Central Anatolia Region of Turkey.

Abstract

Concern about the negative effects of logging residue extraction on the sustainability of forest ecosystems has been rising recently. Tree residues, including leaves, branches, bark and roots, left in the forest after logging may supply most of the nutrients for tree growth. The aim of this study was to (i) determine the carbon and nutrient stocks in different components and (ii) model the carbon and nutrient stocks in tree biomass of a mature Scots pine forest. The study site was located on the Turkmen mountain range in the Central Anatolia Region of Turkey. In sample plots, stand measurements were made, and samples collected from trees, soil and the forest floor for analysis of carbon and nutrients and the stock of each nutrient per unit area were calculated. Data were analysed using analysis of variance and regression analysis. Significant differences were found in carbon and nutrient concentrations and stocks between ecosystem components. C, Ca, Mg, Na, Fe, Cu and Mn stocks were higher in wood; the N stock was higher in needles, and P, K, S and Zn stocks were higher in roots. In the ecosystem, trees had the highest C stock; the soil had the highest N, P, K, Ca, Mg, Na, Cu, Zn and Mn stocks, and the forest floor had the highest Fe and S stocks. Therefore, it is critical that the forest floor is protected as it is an important element of the ecosystem nutrient cycle and source of Fe and S stocks. Maximum attention should be paid to leaving behind needles, bark, roots and thin branches with low economic value to minimise carbon and nutrient loss in the nutrient-limited forests. Equations predicting carbon and nutrient stocks through stem volume can be used for estimation of nutrient loss due to biomass removed from the system through interventions, contributing to sustainable forest management.