Rising atmospheric [CO 2 ], c a , is expected to affect stomatal regulation of leaf gas‐exchange of woody plants, thus influencing energy fluxes as well as carbon (C), water, and nutrient cycling of forests. Researchers have proposed various strategies for stomatal regulation of leaf gas‐exchange that include maintaining a constant leaf internal [CO 2 ], c i , a constant drawdown in CO 2 ( c a − c i ), and a constant c i / c a...

Three young northern temperate forest communities in the north‐central United States were exposed to factorial combinations of elevated carbon dioxide ( CO 2 ) and tropospheric ozone (O 3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity ( NPP...

In order to better understand the nitrogen (N) cycle, a pulse of 15 NO 3 − was applied in 1998 to a sugar maple ( Acer saccharum ) dominated northern hardwood forest receiving long‐term (1994–2008) simulated atmospheric N deposition. Sugar maple leaf litter and live fine‐root 15 N were quantified for four years prior to labeling and for 11 subsequent years. Continuous sampling of 15 N following addition of the tracer enabled c...

We repeatedly sampled the surface mineral soil (0–20 cm depth) in three northern temperate forest communities over an 11‐year experimental fumigation to understand the effects of elevated carbon dioxide (CO 2 ) and/or elevated phyto‐toxic ozone (O 3 ) on soil carbon (C). After 11 years, there was no significant main effect of CO 2 or O 3 on soil C. However, within the community containing only aspen ( Populus tremuloides Michx...

High levels of atmospheric nitrogen (N) deposition in Europe and North America were maintained throughout the 1990s, and global N deposition is expected to increase by a factor of 2.5 over the next century. Available soil N limits primary production in many terrestrial ecosystems, and some computer simulation models have predicted that increasing atmospheric N deposition may result in greater terrestrial carbon (C) storage in...