Biomass, Carbon, and Nitrogen Relations Between Tree Foliage and Organic Soil Layers With Stand Development of <i>Pinus pinaster</i> Over Dune Restoration

ABSTRACT This study aimed to address the knowledge gap by examining the dynamics of biomass, carbon, and nitrogen pools between foliage and forest floor throughout the development of Pinus pinaster plantations in the restoration site of Durusu coastal dune ecosystem in Istanbul‐Türkiye. Live foliage biomass was determined by destructive sampling, while forest floor sampling was carried out separately from litter + fermentation (L + F) and humus (H) layers. Carbon (C) and nitrogen (N) were determined by CN analyzer. The relationship between all calculated variables and the independent variable (D 2 H), derived to represent stand diameter at breast height (D 1.3m ) and tree height (H), was revealed by regression analysis. Average foliage mass was determined as 8 t/ha, C as 4 tC/ha, and N as 0.08 tN/ha. The mean biomass, C, and N of forest floor were 40 t/ha, 12 tC/ha, and 0.3 tN/ha, respectively. Foliage C, N, and C/N ratio showed high relationships with D 2 H as R 2 adj = 0.779, R 2 adj = 0.798, and R 2 adj = 0.943, respectively. However, the differences between the variables of living and non‐living components showed a linear regression relationship with stand development. The differences in forest floor − foliage values showed lower R 2 values with D 2 H. C and N were stored primarily in living foliage in young maritime pine stands where forest floor accumulation is just beginning. However, in older stands, where forest floor has begun to accumulate, forest floor stores more C and N than live foliage. The average C/N ratio of 42.47 for the entire forest floor indicating decomposition is slow, and C and N storage role shifts to forest floor as the stand develops.