We investigated the relationships of net ecosystem carbon exchange ( NEE ), soil temperature, and moisture with soil respiration rate and its components at a grassland ecosystem. Stable carbon isotopes were used to separate soil respiration into autotrophic and heterotrophic components within an eddy covariance footprint during the 2008 and 2009 growing seasons. After correction for self‐correlation, rates of soil respiration...

Efforts to characterize carbon (C) cycling among atmosphere, forest canopy, and soil C pools are hindered by poorly quantified fine root dynamics. We characterized the influence of free‐air‐CO 2 ‐enrichment (ambient +200 ppm) on fine roots for a period of 6 years (Autumn 1998 through Autumn 2004) in an 18‐year‐old loblolly pine ( Pinus taeda ) plantation near Durham, NC, USA using minirhizotrons. Root production and mortality...

The general lack of significant changes in mineral soil C stocks during CO 2 ‐enrichment experiments has cast doubt on predictions that increased soil C can partially offset rising atmospheric CO 2 concentrations. Here, we show, through meta‐analysis techniques, that these experiments collectively exhibited a 5.6% increase in soil C over 2–9 years, at a median rate of 19 g C m −2 yr −1 . We also measured C accrual in deciduous...

Summary We investigated the effects of elevated atmospheric CO 2 concentrations (ambient + 200 ppm) on fine root production and soil carbon dynamics in a loblolly pine ( Pinus taeda ) forest subject to free‐air CO 2 enrichment (FACE) near Durham, NC (USA). Live fine root mass (LFR) showed less seasonal variation than dead fine root mass (DFR), which was correlated with seasonal changes in soil moisture and soil temperature. LF...