A comparison of Fast-Growing Maritime Pine (Pinus pinaster Aiton.) Plantations with Native Broadleaved Vegetation for Greenhouse Gas Balances

Establishing fast-growing plantations is a long-term strategic climate change mitigation option since these plantations may absorb carbon at an accelerated rate and alleviate the pressure on natural forests. In Istanbul, nearly 5% of the forests, totaling 32,603 hectares of natural oak-beech forest ecosystems, were converted to Maritime pine (Pinus pinaster Aiton.) plantations in the 1990s. Maritime pine grows faster than native mixed broadleaf forests but introduces a higher fire risk. The objective of this study was to assess the Greenhouse Gas (GHG) consequences of these conversions by analyzing wildfire emissions and carbon stock changes for a period of 2 decades after conversion. The carbon modeling was done using the CBM-CFS3 model calibrated with ground measurements. The results revealed that the total ecosystem carbon stocks would remain at 97.9 tC/ha (Avoided Species Conversion/ASC scenario) compared to 116.7 tC/ha in the Business as Usual (BAU) scenario. The BAU scenario refers to real life conditions that the species conversions have occurred. The fire emissions had a minor share in total ecosystem GHG balance, because the burnt area rate was low (around 0.1 percent) during the assessment period.