Atmospheric fluxes and concentrations of monoterpenes in resin-tapped pine forests

Measurement of VOC emission from exposed resin to the atmosphere was done along the 1-year cycle in resin-tapped pine forests. Emissions are composed mainly of α- and β-pinene. Emission rates depend in a complex way of the resination cycle, being influenced by ambient temperature and resin-tapping practices associated with the frequency of bark removal and the application of acidic active past in tree wounds. An algorithm with an exponential dependence of emission rate on temperature was calculated from the field experiments and used to estimate average annual emission fluxes from Portuguese resin-tapped pine forests. Emissions from resin are clearly dominant over evaporation from leaves in resin-tapped forests, being relevant to the atmospheric biogenic VOC budget in Portugal.