Soil respiration (Rs), the largest carbon emission flux in ecosystems is usually modelled as an empirically parameterized function of temperature (Ts), and sometimes water availability (Ɵ). The likely contribution by other factors, such as carbohydrate substrate supply from photosynthesis hasve been recognized, but modeling capacity to use this information is limited. In the current study… More

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Northern hemisphere evergreen forests assimilate a significant fraction of global atmospheric CO2 but monitoring large-scale changes in gross primary production (GPP) in these systems is challenging. Recent advances in remote sensing allow the detection of solar-induced chlorophyll fluorescence (SIF) emission from vegetation, which has been empirically linked to GPP at large spatial scales. This is… More

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Wetlands are the most important natural source of methane (CH4) to the atmosphere, and there is still considerable uncertainty of CH4 flux and net carbon budgets of wetlands. This uncertainty is due in part to the complex role of wetland vegetation in controlling methane production, oxidation and transport, which challenge the modeling and forecast of… More

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Loss of coastal wetlands is occurring at an increasingly rapid rate due to drainage of these wetlands for alternative land-uses, which also threatens carbon (C) storage in these C-rich ecosystems. Wetland drainage results in water table drawdown and increased peat aeration, which enhances decomposition of previously stabilized peat and changes stable C isotope profiles. The… More

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Heterotrophic respiration (Rh), microbial processing of soil organic matter to carbon dioxide (CO2), is a major, yet highly uncertain, carbon (C) flux from terrestrial systems to the atmosphere. Temperature sensitivity of Rh is often represented with a simple Q10 function in ecosystem models and earth system models (ESMs), sometimes accompanied by an empirical soil moisture… More

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Anthropogenic carbon dioxide (CO2) emissions dominate the atmospheric greenhouse gas radiative forcing budget. However, these emissions are poorly constrained at the regional and seasonal scales. Here, we use a combination of tall tower CO2 mixing ratio and carbon isotope ratio observations and inverse modeling techniques to constrain anthropogenic CO2 emissions within a highly heterogeneous agricultural… More

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The phenological response of vegetation to ongoing climate change may have great implications for hydrological regimes in the eastern United States. However, there have been few studies that analyze its resultant effect on catchment discharge dynamics, separating from dominant climatic controls. In this study, we examined the net effect of phenological variations on the long‐term… More

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AmeriFlux scientists were early adopters of a network-enabled approach to ecosystem science that continues to transform the study of land-atmosphere interactions. In the 20 years since its formation, AmeriFlux has grown to include more than 260 flux tower sites in the Americas that support continuous observation of ecosystem carbon, water, and energy fluxes. Many of… More

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Strategies to mitigate carbon dioxide emissions through forestry activities have been proposed, but ecosystem process-based integration of climate change, enhanced CO2, disturbance from fire, and management actions at regional scales are extremely limited. Here, we examine the relative merits of afforestation, reforestation, management changes, and harvest residue bioenergy use in the Pacific Northwest. This region… More

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The first European Space Agency (ESA) and NASA collaboration in an airborne campaign to support ESA’s FLuorescence EXplorer (FLEX) mission was conducted in North Carolina, USA during September-October 2013 (FLEX-US 2013) at the Parker Tract Loblolly Pine (LP) Plantation (Plymouth, NC, USA). This campaign combined two unique airborne instrument packages to obtain simultaneous observations of… More

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