The paper by Peron et al. addressees the topic of BVOC emission of Quercus trees and underlying physiology in response to a combination of drought and ozone stress. It specifically checks a key question of whether the different stresses have an additive of differential effects. The paper is clearly within the scope of BG and addresses a timely question. Two expert reviewers provided generally supportive review with extensive and useful comments that requires major revisions. The author's response shows that they can adequately address the comments and propose an improved version of the paper. I therefore recommend to invite the authors to submit a revised version that can be checked again before publication.

The paper on aspects of the non-additive effects of drought and ozone stress on VOC emission deals with an important topic and is well within the scope of BG. It received generally supportive reviews in the first round, but some significant issues were raise requiring revisions. The revised version has not been checked by the two reviewers and both find the revisions satisfactory and support publication in the present form. I concur and agree that the authors addressed all the comments and that paper has been improved. I therefore recommend its publication in BG.