An Ameriflux site was established in mid 1996 to study the exchange of CO2 in a native tallgrass prairie of north-central Oklahoma, USA. Approximately the first 20 months of measurements (using eddy covariance) are described here. This prairie, dominated by warm season C4 grasses, is typical of the central Kansas/northern Oklahoma region. During the first… More

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Atmospheric deposition during the growing season contributes one-third or more of the estimated total flux of lead, zinc, and cadium from the forest canopy to soils beneath an oak stand in the Tennessee Valley but less than 10 percent of the flux of manganese. The ratio of the wet to dry deposition flux to the… More

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Tropical vegetation is a major source of global land surface evapotranspiration, and can thus play a major role in global hydrological cycles and global atmospheric circulation. Accurate prediction of tropical evapotranspiration is critical to our understanding of these processes under changing climate. We examined the controls on evapotranspiration in tropical vegetation at 21 pan-tropical eddy… More

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This study evaluates age-related patterns of ecosystem carbon (C) fluxes in a chronosequence (5-, 18-, 33-, and 68-year old in 2007) of planted pine (Pinus strobus L.) forests in southern Ontario, Canada, from 2003 to 2007. Carbon fluxes determined with the eddy covariance technique were normalized by differences in site index (SI; a measure of… More

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Soil respiration is an important component of the annual carbon balance of forests, but few studies have addressed interannual variation in soil respiration. The objectives of this study were to investigate the seasonal and interannual variation in soil respiration, temperature, precipitation, and soil water content in two New England forest soils and to develop and… More

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Eddy covariance measurements of carbon dioxide and water vapor exchange were made above a ponderosa pine (Pinus ponderosa Dougl. ex P. and C. Laws.) forest located in a semiarid environment in central Oregon. The stand is a mixture of old-growth and young trees. Annual net carbon gain by the ecosystem (NEE) was 320 ± 170 gC m−2year−1 in 1996… More

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We estimated aboveground tree biomass and change in aboveground tree biomass using repeated airborne laser scanner (ALS) acquisitions and temporally coincident ground observations of forest biomass, for a relatively undisturbed period (2004–2007; ∆07–04), a contrasting period of disturbance (2007–2009; ∆09–07), and an integrated period (2004–2009; ∆09–04). A simple random sampling (SRS) estimator was used to… More

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