Most land surface and ecosystem models assume that a vegetated canopy can be abstracted as a turbid medium when such models compute mass, energy, and carbon exchange. However, those models fail to simulate radiation environments in heterogeneous landscapes. This study aims to couple a spatially explicit three-dimensional (3D) shortwave …
Journal: Agricultural And Forest Meteorology, Volume 152: 83-100 (2012), ISBN . DOI: 10.1016/j.agrformet.2011.09.008 Sites: US-Ton
Responses of wetland productivity to changes in water table depth (WTD)
are controlled by complex interactions among several soil and plant
processes, and hence are site-specific rather than general in nature.
Hydrological controls on wetland productivity were studied by
representing …
Journal: Biogeosciences, Volume 9 (11): 4215-4231 (2012), ISBN . DOI: 10.5194/bg-9-4215-2012 Sites: US-Los
Ecosystem respiration (Reco) is highly variable in semiarid ecosystems. After a period of drought, Reco can jump to a high value in response to rain events, and afterward it decays exponentially with time. To better understand the timing, size, and duration of rain-induced …
Journal: Agricultural And Forest Meteorology, Volume 154-155: 203-213 (2012), ISBN . DOI: 10.1016/j.agrformet.2011.11.007 Sites: US-Snd
Two distinct nocturnal subcanopy flow regimes are observed beneath a tall (16 m) open pine forest canopy. The first is characterized by weaker mixing, stronger stability, westerly downslope flow decoupled from the flow above the canopy and much smaller than expected …
Journal: Agricultural And Forest Meteorology, Volume 152: 101-108 (2012), ISBN . DOI: 10.1016/j.agrformet.2011.09.004 Sites: US-Me2
Understanding the relative contribution of environmental and substrate controls on rice paddy methanogenesis is critical for developing mechanistic models of landscape-scale methane (CH4) flux. A diurnal pattern in observed rice paddy CH4 flux has been attributed to fluctuations in soil temperature physically …
Journal: Geophysical Research Letters, Volume 39 (6): n/a-n/a (2012), ISBN . DOI: 10.1029/2012gl051303 Sites: US-Twt
The paradigm that winter is a dormant period of soil biogeochemical activity in high elevation or high latitude ecosystems has been amply refuted by recent research. Carbon dioxide (CO2) released from cold or snow-covered soil is a substantial component of total annual ecosystem carbon fluxes. Recent investigations have …
Journal: Arctic, Antarctic, And Alpine Research, Volume 44 (2): 247-254 (2012), ISBN . DOI: 10.1657/1938-4246-44.2.247 Sites: US-Fwf
The effects of early growing season droughts on water and carbon balances in conifer forests are poorly understood. In this study, the response of canopy transpiration (Ec) and growth …
Journal: Hydrological Processes, Volume 26 (12): 1779-1791 (2012), ISBN . DOI: 10.1002/hyp.9315 Sites: CA-TP4
We report on methane (CH4) concentrations and efflux densities that were measured over a drained and grazed, peatland pasture in the Sacramento-San Joaquin River Delta of California over a three year period. The site was ideal for micrometeorological flux measurements due to its very flat topography, its …
Journal: Agricultural And Forest Meteorology, Volume 153: 177-187 (2012), ISBN . DOI: 10.1016/j.agrformet.2011.04.013 Sites: US-Snd
The Sacramento-San Joaquin Delta in California was drained and converted to agriculture more than a century ago, and since then has experienced extreme rates of soil subsidence from peat oxidation. To reverse subsidence and capture carbon there is increasing interest in converting drained agricultural land-use types …
Journal: Agriculture, Ecosystems & Environment, Volume 150: 1-18 (2012), ISBN . DOI: 10.1016/j.agee.2012.01.009 Sites: US-Snd, US-Twt
Net ecosystem productivity (NEP) of seasonally dry grasslands in Mediterranean climate zones is determined by the duration and intensity of rainy vs. dry seasons. Precipitation in these zones is expected to decline with climate change during the next century, possibly reducing NEP. Ecosystem models used to study climate …
Journal: Agricultural And Forest Meteorology, Volume 152: 189-200 (2012), ISBN . DOI: 10.1016/j.agrformet.2011.09.012 Sites: US-Var