Estimates of biomass and carbon stock in beech high forests in Serbia

With the aim of resolving complex problems of mankind, energy crisis, and climate changes, scientists worldwide have recognized the importance of studying biomass as well as carbon stock and cycling in forest ecosystems. There haven’t been any significant investigations of this kind in Serbia (Koprivica et al. 2010, Koprivica and Matović 2011, Koprivica et al. 2011). The sample taken for the purposes of this investigation consists of eleven pure beech high stands selected in six forest areas or nine management units. They are all uneven-aged stands that have been managed mostly by applying selection and group selection management systems for several decades. The stands have a specific structural form and they used to be virgin forests at the beginning of the twentieth century. Their site class is I/II-III/IV, the altitude ranges from 400 to 1380 m. One stand is classified as submontane (Fagenion moesiacae submontanum B. Jov. 1976), and the other ten as montane (Fagenion moesiacae montanum B. Jov. 1976) beech forests. Systematic sampling was used for the purposes of determining dry biomass of aboveground and belowground living trees. Deadwood was studied as well, but the results will be presented in a separate paper. Circular sample plots of 500 m2 in size arranged in a grid of 100 x 100 m were used as sample elements in the stands. A set of 242 sample plots was established. The measurements included diameter at breast height and height of all living trees on the sample plots. Total tree biomass and carbon stock were calculated by applying regression equations (Wutzler et al. 2008, Joosten et al. 2004). Both simple and stratified sampling were used for estimating the average and total biomass and carbon stock. The average dry biomass of the stands above and below ground was estimated at 296.40 t ha-1, and the average carbon stock at 146.41 tC ha- 1. The aboveground biomass participates with 85.7% and the belowground with 14.3%. It can be concluded that regarding their site production potential and projected optimal compositions, beech high stands in Serbia have biomass and carbon stock lower than expected, which is primarily due to inadequate implementation of management systems.