The Southern Great Plains are characterized by a fine-scale mixture of different land-cover types, predominantly winter-wheat and grazed pasture, with relatively small areas of other crops, native prairie, and switchgrass. Recent droughts and predictions of increased …
Journal: Agriculture, Ecosystems & Environment, Volume 213: 209-218 (2015), ISBN . DOI: 10.1016/j.agee.2015.07.021 Sites: US-ARM
We investigated the impact of the 2011 severe drought on summer evapotranspiration (ET) and energy partitioning of a managed Old World bluestem grassland in the Southern Great Plains and compared the results with those from 2010, a hydrologically wet year. Measurements of CO2, latent heat (LE), and sensible heat (H) fluxes …
Journal: Ecohydrology, Volume 8 (7): 1194-1204 (2015), ISBN . DOI: 10.1002/eco.1574 Sites: US-LGr
Freshwater marshes are well-known for their ecological functions in carbon sequestration, but complete carbon budgets that include both methane (CH4) and lateral carbon fluxes for these ecosystems …
Journal: Global Change Biology, Volume 21 (3): 1165-1181 (2015), ISBN . DOI: 10.1111/gcb.12760 Sites: US-WPT
Global-scale studies indicate that semiarid regions strongly regulate the terrestrial carbon sink. However, we lack understanding of how climatic shifts, such as decadal drought, impact carbon sequestration across the wide range of structural diversity in semiarid ecosystems. Therefore, we used eddy covariance measurements to quantify …
Journal: Journal Of Geophysical Research: Biogeosciences, Volume 120 (12): 2612-2624 (2015), ISBN . DOI: 10.1002/2015JG003181 Sites: US-SRG, US-Whs, US-Wkg
Eddy covariance nighttime fluxes are uncertain due to potential measurement biases. Many studies report eddy covariance nighttime flux lower than flux from extrapolated chamber measurements, despite corrections …
Journal: Global Change Biology, Volume 21 (2): 708-721 (2015), ISBN . DOI: 10.1111/gcb.12731 Sites: US-GLE
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 …
Journal: Agricultural And Forest Meteorology, Volume 201: 61-75 (2015), ISBN . DOI: 10.1016/j.agrformet.2014.10.017 Sites: US-PFa
Standardized reference evapotranspiration (ET) and ecosystem-specific vegetation coefficients are frequently used to estimate actual ET. However, equations for calculating reference ET have not been well validated in tropical environments. We measured ET (ETEC) using eddy covariance (EC) towers at two irrigated sugarcane …
Journal: Hydrology And Earth System Sciences, Volume 19 (1): 583-599 (2015), ISBN . DOI: 10.5194/hess-19-583-2015 Sites: US-SuS, US-SuW
Temperate forests play an important role in the global
carbon cycle, and are thought to currently be a sink for
atmospheric CO2. However,we lack understanding of
the drivers of forest carbon accumulation and loss,
hampering our ability to predict carbon cycle
responses to global change. In this study,we used CO2
flux and radiocarbon …
Journal: Ecosystems, Volume 18: 459-470 (2015), ISBN . DOI: Sites: US-Wrc
It is necessary to partition eddy covariance measurements of carbon dioxide exchange into its offsetting gross fluxes, canopy photosynthesis, and ecosystem respiration, to understand the biophysical controls on the net fluxes. And independent estimates of canopy photosynthesis (G) and ecosystem respiration (R) are needed to validate …
Journal: Agricultural and Forest Meteorology, Volume 207: 117-126 (2015), ISBN . DOI: 10.1016/j.agrformet.2015.03.010 Sites: CA-Ca1, CA-Ca2, CA-Ca3, CA-Let, CA-Mer, CA-NS1, CA-NS3, CA-NS5, CA-NS6, CA-NS7, CA-Oas, CA-Obs, CA-Ojp, CA-Qcu, CA-Qfo, CA-SJ2, CA-SJ3, CA-TP4, CA-WP1, US-ARM, US-Aud, US-Bo1, US-Ho1, US-Ho2, US-IB2, US-KS2, US-MMS, US-MOz, US-NC2, US-NR1, US-SO2, US-SO3, US-SO4, US-SP2, US-SP3, US-SRM, US-Ton, US-Tw3, US-UMB, US-Var, US-WBW, US-Wkg, US-Wrc
Journal: Journal of Geophysical Research: Biogeosciences, Volume 121: 188-204 (2015), ISBN . DOI: 10.1002/2015jg003054 Sites: US-Myb