Role of different components of urban and peri-urban forests to store carbon – a case-study of the Sandanski region, Bulgaria

Urban areas currently make up about 4% of the world’s terrestrial surface and
forest parks as elements of Green Infrastructure (GI) is currently of interest in their potential to store carbon. We studied carbon stocks in different components of urban and peri-urban forest parks: urban soils, forest floor and aboveground tree vegetation in Sandanski, Bulgaria. For all urban sites compared to controls, the value of carbon stocks in soils was much greater. In urban soils of Sandanski carbon stocks varied between 44 and 88 tCha-1, compared to peri-urban 32 - 39 tCha-1. The reverse was observed for carbon stocks in the forest floor and tree stands. Forest floor carbon stocks in Sandanski varied within 4.07 - 4.37 tCha-1, while in peri-urban were higher (5.50 - 3.47 tCha-1).

Carbon stored in aboveground tree biomass in urban sites was calculated at 36.5 tCha-1 for Sandanski and in peri-urban sites 37.0 and 67.8 tCha-1, respectively. We concluded that carbon accumulation in urban forest parks is controlled by detailed management activities and confirmed their high potential to store carbon. It is clearly argued that there is a need to maintain and enhance the ecological functions of forest ecosystems as part of urban GI, which in turn will support the mitigation of sharp climatic changes at the local and regional levels.