Determination of Carbon, Nitrogen and Phosphorus Stocks and Stoichiometry in Broadleaf Mixed Forest Soil and Litterfall: A case study in Oltu district, Erzurum

Abstract

It is necessary to provide plant nutrients in soil at optimal levels for the sustainability of forest ecosystems. The soil stoichiometry of total carbon (C), total nitrogen (N) and total phosphorus (P) allow monitoring and assessment of ecosystem structures and variations in nutrient cycle. Studies on determination of C-N-P stoichiometry in forest ecosystems, however, are somewhat inadequate. This study aims to determine change of C-N-P stoichiometry depending on litterfall condition and soil depth in broadleaf mixed forest (Europen Hophornbeam -Syspirensis Oak) soil and the C-N-P stocks in soil. In this context, we were determined both C-N-P stoichiometry and C-N-P stock in soil and litterfall by conducting field studied at 10 different points in the Broad Leaf Mixed Forest of Erzurum-Oltu district. The results indicated that as the depth of the soil increased, the C-N ratio decreased, whereas the N-P and the C-P ratios increased. Positive correlations were observed between C-N in all soil depths, but negative correlations between C-P and N-P. The correlation coefficients between C and N (r0-10= 0.58, r10-20= 0.52 and r20-30= 0.44) and between C and P (r0-10= 0.64, r10-20= 0.54 and r20-30= 0.42) and between N and P (r0-10= 0.52, r10-20= 0.35 and r20-30= 0.36) decreased as soil depth increased. The mean scores of the C-N-P stocks were determined as 5.9, 1.3, and 0.2 ton ha -1 in litterfall and 157.68, 24.60, and 2.68 tons ha -1 in soil, respectively. It is important to rehabilitate degraded forests and minimize the negative effects of erosion in order to increase the amount of carbon captured in forest soils. In addition, the variable C: N: P stoichiometry in forest ecosystems; It can be considered as a leading indicator of soil degradation and drought and climate changes.