A survey of carbon sequestration potential of orchards and vineyards in Italy

Orchards and vineyards are important land use types in Southern Europe. In spite of their potential to sequester atmospheric C and to mitigate climate change, relatively little is known regarding the influx and outflux of C in these systems. The aim of this work is to provide data on the C budget, including net primary production (NPP), C removal through production, and C sequestration potential for the vineyards and the main fruit tree species (apple, citrus, olive, and peach) grown in Italy. Standing biomass and NPP were measured, and net ecosystem exchange and net C balance assessed directly, through either eddy covariance technique, or considering NPP and heterotrophic respiration. Aboveground NPP ranged between 10 and 20 t ha-1 while, when directly assessed, belowground NPP was less than 20% of the total NPP. The C leaving the system through fruit production ranged between 2 and 3 t ha-1. Mature fruit tree ecosystems had positive net ecosystem productivity (ranging from 4.30 in Apple-2 to 7.5 in Grape-1.) and net ecosystem carbon balance (ranging from 0.6 to 5.9 t C ha-1 y-1), indicating the potential of these systems to store C.