Journal: Agric. Forest Meteorol., Volume 149: 582-602 (2009), ISBN . DOI: Sites: US-Uaf
The seasonal and interannual variability of gross ecosystem photosynthesis (Pg) and
ecosystem respiration (Re), and their relationships to environmental variables and stand
characteristics were used to explain the variation of eddy-covariance-measured net
ecosystem productivity (FNEP) of three different-aged Douglas-fir stands …
Journal: Journal Of Geophysical Research, Volume 114 (G4): (2009), ISBN . DOI: doi:10.1029/2008JG000912 Sites: CA-Ca1, CA-Ca2, CA-Ca3
Similar nonsteady-state automated chamber systems were used to measure and partition
soil CO2 efflux in contrasting deciduous (trembling aspen) and coniferous (black spruce
and jack pine) stands located within 100km of each other near the southern edge of the
Boreal forest in Canada. The stands were exposed to similar climate …
Journal: Global Change Biology, Volume 15 (5): 1302-1319 (2009), ISBN . DOI: 10.1111/j.1365-2486.2008.01830.x Sites: CA-Oas, CA-Obs, CA-Ojp
Journal: Global Change Biology, Volume 16 (8): 2252-2271 (2009), ISBN . DOI: 10.1111/j.1365-2486.2009.02138.x Sites: US-MOz
Recent studies have demonstrated direct methane emission from plant foliage under aerobic conditions, particularly under high ultraviolet (UV) irradiance. We examined the potential importance of this phenomenon in a high-elevation conifer forest using micrometeorological techniques. Vertical profiles of methane and carbon dioxide …
Journal: Biogeosciences, Volume 6 (7): 1311-1324 (2009), ISBN . DOI: 10.5194/bg-6-1311-2009 Sites: US-NR1
Ecosystem level ozone (O3) fluxes during four different years were examined at a subalpine forest site in the Colorado Rocky Mountains. The local mountain–valley wind system and the proximity of the Denver Metropolitan area leads to high summertime ozone episodes on many afternoons. The timing between these episodes and the ecosystem …
Journal: Agricultural And Forest Meteorology, Volume 149 (9): 1447-1459 (2009), ISBN . DOI: 10.1016/j.agrformet.2009.04.001 Sites: US-NR1
A system to make atmospheric measurements from a moving trolley suspended by a stretched cable has been developed. At present, these measurements consist of wind velocity, temperature, humidity, and carbon dioxide concentration, though other sensors may be added. The track consists of cable segments attached to turns mounted on standard …
Journal: Journal Of Atmospheric And Oceanic Technology, Volume 26 (3): 462-473 (2009), ISBN . DOI: 10.1175/2008JTECHA1158.1 Sites: US-NR1
Eddy covariance measurements of the surface energy balance and carbon dioxide exchange above high-elevation (3,480 m above sea level) alpine tundra located near Niwot Ridge, Colorado, were compared to simultaneous measurements made over an adjacent subalpine forest over two summers and one winter, from June 9, 2007 to July 3, 2008. …
Journal: Biogeochemistry, Volume 95 (1): 61-76 (2009), ISBN . DOI: 10.1007/s10533-009-9325-9 Sites: US-NR1
The construction and deployment of a portable trace-gas measurement system (TGaMS) is described. The air-collection system (dubbed HYDRA) collects air samples from 18 different locations and was connected to either one or two LI-COR LI-7000 gas analyzers to measure CO2. An in situ “field calibration” method, that uses four calibration …
Journal: Journal Of Atmospheric And Oceanic Technology, Volume 26 (2): 291-316 (2009), ISBN . DOI: 10.1175/2008JTECHA1080.1 Sites: US-NR1, US-NR2
Considerable research has recently been devoted to understanding biogeochemical processes under winter snow cover, leading to enhanced appreciation of the importance of many winter ecological processes. In this study, a comprehensive investigation of the stable carbon isotope composition (δ13C) of CO2 within a high-elevation subalpine …
Journal: Biogeochemistry, Volume 95 (1): 37-59 (2009), ISBN . DOI: 10.1007/s10533-008-9233-4 Sites: US-NR1