Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

Alan F. Talhelm, Kurt S. Pregitzer, Mark E. Kubiske, Donald R. Zak, Courtney E. Campany, Andrew J. Burton, Richard E. Dickson, George R. Hendrey, J. G. Isebrands, Keith F. Lewin, John Nagy, David F. Karnosky