Carbon dynamics of soil organic matter in bulk soil and aggregate fraction during secondary succession in a Mediterranean environment

abstract Article history:Received 30 May 2012Received in revised form 21 August 2012Accepted 30 August 2012Available online xxxxKeywords:Soil carbon turnoverMediterranean successionStable carbon isotopesC 3 –C 4 and C 4 –C 3 vegetation change Clarifying which factors causean increase ordecrease in s oilorganiccarbon(SOC)afteragriculturalabandonmentrequires integration of data on the temporal dynamics of the plant community and SOC. A chronosequence ofabandoned vineyards was studied on a volcanic island ( Pantelleria, Italy). Vegetation in the abandoned fieldswas initially dominated by annual and perennial herbs, then by Hyparrhenia hirta (L.) Stapf, and finally bywoody communities. As a consequence, the dom inant photosynthetic pathway changed from C 3 to C 4 and thenback to C 3 . Conversion of a plant community dominated by one photosynthetic pathway to another changesthe 13 C/ 12 C ratio of inputs to SOC. Using the time since abandonment and the shift in belowground δ 13 CofSOCrelative to the aboveground δ