The carbon storage potential of terrestrial ecosystems depends in part on how atmospheric conditions influence the type and amount of surface radiation available for photosynthesis. Diffuse light, resulting from interactions between incident solar radiation and atmospheric aerosols and clouds, has been postulated to increase carbon uptake in terrestrial ecosystems. However, the magnitude of the diffuse… More

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Simulating the magnitude and variability of terrestrial methane sources and sinks poses a challenge to ecosystem models because the biophysical and biogeochemical processes that lead to methane emissions from terrestrial and freshwater ecosystems are, by their nature, episodic and spatially disjunct. As a consequence, model predictions of regional methane emissions based on field campaigns from… More

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Given that forests represent the primary terrestrial sink for atmospheric CO2, projections of future carbon (C) storage hinge on forest responses to climate variation. Models of gross primary production (GPP) responses to water stress are commonly based on remotely sensed changes in canopy ‘greenness’ (e.g., normalized difference vegetation index; NDVI). However, many forests have low… More

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In this paper, we analyzed 3 years of carbon flux data from continuous eddy covariance measurements to investigate how soil moisture, rain pulses, and growth alter the response of ecosystem respiration to temperature. The data were acquired over an annual grassland and from the grass understory of an oak/grass savanna ecosystem in California. We observed… More

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Agricultural drainage of organic soils has resulted in vast soil subsidence and contributed to increased atmospheric carbon dioxide (CO2) concentrations. The Sacramento-San Joaquin Delta in California was drained over a century ago for agriculture and human settlement and has since experienced subsidence rates that are among the highest in the world. It is recognized that… More

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The application of the eddy covariance flux method to measure fluxes of trace gas and energy between ecosystems and the atmosphere has exploded over the past 25 years. This opinion paper provides a perspective on the contributions and future opportunities of the eddy covariance method. First, the paper discusses the pros and cons of this… More

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To test the capabilities of newly available instrumentation and to explore the dynamics of carbonyl sulfide(COS) as a proxy for the measurement of canopy-scale gross primary production (GPP), we conducted an experiment to measure the simultaneous net transfer of COS and CO2 between the atmosphere and a growing wheat canopy, senesced wheat, and the harvested… More

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Ozone stress has become an increasingly significant factor in cases of forest decline reported throughout the world. Current metrics to estimate ozone exposure for forest trees are derived from atmospheric concentrations and assume that the forest is physiologically active at all times of the growing season. This may be inaccurate in regions with a Mediterranean… More

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We present the first canopy-scale, continuous, long-term flux measurements of a suite of oxygenated volatile organic compounds (OVOCs). Fluxes were measured above a ponderosa pine plantation, adjacent to the Blodgett Forest Research Station (38°53′42.9″N, 120°37′57.9″W, 1315 m elevation), with a fully automated relaxed eddy accumulation (REA) system coupled to a dual GC-FID system. Quantified OVOCs… More

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