Türkiye'deki Karaçam ((Pinus nigra Arnold subsp. pallasiana (Lamb.) Holmboe)) - Kızılçam (Pinus brutia Ten.) karışık meşcerelerinin biyokütle ve karbon depolamanin yapay sinir ağları kullanılarak modellenmesi

This study was conducted in 21 FMDs of 13 DFMs across Türkiye. The aim was to develop prediction models for biomass and carbon storage in natural mixed stands of Pinus nigra and Pinus brutia. In addition to dendrometric measurements (diameter, height, age), 138 trees of P. nigra (68) and P. brutia (70), 138 stem sections, 138 branches and leaves, 92 litter, 46 deadwood, 46 herbaceous covers, 208 root cylinders, and 206 organic soil cylinders samples were utilized. Stand characteristics were analyzed through several key parameters (age, diameter, height, tree density, basal area, volume, and mixture ration). Biomass and carbon stocks were calculated for each aboveground pool (individual tree, stem, branches, leaves, bark, litter, deadwood, herbaceous cover) and belowground (roots and organic matter). The results indicated that the average biomass and carbon stock per single-tree were 162.56 kg and 80.72 kg for P. nigra, and 195.63 kg and 98.25 kg for P. brutia respectively. The stem accounted for 64-66% of an individual tree's biomass and 63-66% of its carbon stock, followed by branches, leaves, and bark. In the biomass of litter (17.4 t/ha), deadwood (2.33 t/ha), herbaceous cover (0.45 t/ha), roots at 0-90 cm (55.60 t/ha), and mass of soil organic matter (7560.9 t/ha), the carbon stock represented 44.5%, 47.7%, 46.1%, 48.1%, and 3.35% respectively. Using ANN and Regression analysis methods, several prediction models were developed for biomass and carbon storage. For each species, (i) top 10 non-linear regression models (Power) for each tree components and for individual tree, using only tree diameter (D1.30), (ii) two MLR models and (iii) two MLP models for each individual tree, using D1.30 and height (H), as well as (iv) two MLR models and two MLP models for stand level using five stand parameters, were developed. Compared to the MLR models, the MLP models demonstrated better performance for prediction of biomass and carbon storage. The spatial distribution and the potential biomass and carbon stored by all mixed stands of P. nigra and P. brutia were analyzed. The carbon stock capacity of these ecosystems represents about 3.31% (0.066 GtC) of the country's total forest ecosystem carbon stock capacity (Türkiye).