Determination of carbon stock changes: biomass models or biomass expansion factors

Abstract

It was aimed to reveal the usability of Geographical Information System (GIS) in determination of land usage changes and carbon stock changes by an examined case, and to determine the efficiency and reliability of biomass expansion factors (BEFs) in determination of carbon stock changes. With this purpose, the maps of field usage changes and carbon stock changes according to plan arrangement periods were prepared, and then, biomass and carbon amounts were determined and compared according to growth models of tree species and BEFs. As a result of performed researches, it was understood that GIS technology, where forest inventory information can be evaluated during determining the field usage changes as well as stored biomass and carbon stock amounts in planning units, is efficient and smoother. The calculations performed by using BEFs gave values 17% more than those with models. This situation conflicts with the expectation that calculations must be complete and accurate, and it also casts doubts on usage of BEFs. Rather than usage of BEFs, it is seen that usage of models based on estimation of aboveground and belowground biomass values of standing stem volume data and their commercial and noncommercial parts are the most appropriate methods for obtaining reliable results