Analysis spatiotemporal changes of carbon storage in forest ecosystems: A case study in Hisar planning unit

Investigation of the spatiotemporal patterns of carbon dynamics in forest ecosystems plays an important role for understanding the role of forests in the carbon cycle and developing effective forestry policies to mitigate the negative impacts of climate change. In this study, temporal and spatial changes in carbon stocks in Hisar planning unit between 1973 and 2015 were investigated to take into account different carbon pools such as above ground biomass, under ground biomass, dead wood, litterfall and soil organic matter. The effects of changes in forest structure such as land cover, stand closure, stand development age and age class distribution on carbon dynamics were analyzed. The carbon sequestration and densities calculated for different carbon pools in each plan period and periodically changes in carbon sequestration were mapped with ArcGIS 10TM. As a result, total carbon storage increased by 25.55% between 1973 and 2015. The average annual carbon accumulation rates were 0.22 Mg ha-1, 0.11 Mg ha-1 and 0.085 Mg ha-1 for the periods 1973-1998, 1998-2015 and 1973-2015, respectively. The greatest contribution to the carbon pool was made by soil organic matter, while the lowest contribution was made from dead wood biomass. Besides, the results showed that pure cover types, "d" development stages, full canopy covers and over-mature stands (81-100) contribute more to carbon density. Consequently, the conversion from degraded, coppices, bare forest and non-forest areas to productive forests resulted in an increase in forest coverage and total carbon storage. These temporal changes in stand structure affect the spatial distribution of carbon dynamics. Mapping carbon dynamics provides opportunities for forest planners in developing forest policies and management plans based on ecological sustainability of carbon pools and mitigating climate change effects.