Effects Of Past And Current Disturbance On Carbon Cycling In Grassland Mesocosms

Abstract In species rich grasslands, management factors may affect carbon storage both directly (e.g. defoliation) and indirectly, by altering plant community structure. We set up a mesocosm experiment to separate these direct and indirect effects. Monoliths were sampled from two plots of a semi-natural, species-rich pasture at Theix (France), which had been subjected to contrasted disturbance levels, high versus low grazing, for 14 years. These monoliths were placed in transparent enclosures in natural light and temperature conditions. At the start of the experiment, half of the monoliths in each disturbance treatment were shifted to the opposite disturbance regime. Above and below ground CO2 fluxes were then measured continuously over 2 years. The net below ground carbon storage was positively correlated (P