No impact of tropospheric ozone on the gross primary productivity of a Belgian pine forest

High stomatal ozone (O-3) uptake has been shown to negatively affect crop yields and the growth of tree seedlings. However little is known about the effect of O-3 on the carbon uptake by mature forest trees. This study investigated the effect of high O-3 events on gross primary productivity (GPP) for a Scots pine stand near Antwerp Belgium over the period 1998-2013. Stomatal O-3 fluxes were modelled using in situ O-3 mixing ratio measurements and a multiplicative stomatal model which was parameterised and validated for this Scots pine stand. Ozone-induced GPP reduction is most likely to occur during or shortly after days with high stomatal O-3 uptake. Therefore a GPP model within an artificial neural network was parameterised for days with low stomatal O-3 uptake rates and used to simulate GPP during periods of high stomatal O-3 uptake. Possible negative effects of high stomatal O-3 uptake on GPP would then result in an overestimation of GPP by the model during or after high stomatal O-3 uptake events. The O-3 effects on GPP were linked to AOT40 and POD1. Although the critical levels for both indices were exceeded in every single year no significant negative effects of O-3 on GPP were found and no correlations between GPP residuals and AOT40 and POD1 were found. Overall we conclude that no O-3 effects were detected on the carbon uptake by this Scots pine stand.

Jaar van publicatie:2017

Trefwoorden:A1 Journal article

BOF-keylabel:ja

BOF-publication weight:6

CSS-citation score:1

Authors from:Government

Toegankelijkheid:Open