Fluxes of carbon dioxide, water and energy between a temperate deciduous forest and the atmosphere were quantified across time scales of hours, days, seasons, years and decades. This exercise was performed using stand-level eddy covariance flux measurements and a biophysical model, CANOAK. The CANOAK model was tested with measurements …
Journal: Ecological Modelling, Volume 142 (1-2): 155-184 (2001). DOI: 10.1016/s0304-3800(01)00287-3 Sites: US-WBW
A multi-year, multi-technique study was conducted to measure evapotranspiration and its components within an uneven-aged mixed deciduous forest in the Southeastern United States. Four different measurement techniques were used, including soil water budget (1 year), sap flow …
Journal: Agricultural And Forest Meteorology, Volume 106 (2): 153-168 (2001). DOI: 10.1016/s0168-1923(00)00199-4 Sites: US-WBW
Journal: Tree Physiology, Volume 21 (6): 345-358 (2001). DOI: 10.1093/treephys/21.6.345 Sites: US-WBW
At a deciduous forest in the southeast United States (Walker Branch Watershed, Oak Ridge, Tennessee), as at other sites with tall vegetation and/or complex terrain, it is difficult to temporally integrate …
Journal: Journal Of Geophysical Research: Atmospheres, Volume 106 (D24): 34167-34178 (2001). DOI: 10.1029/2001jd000624 Sites: US-WBW
The energy balance components were measured above the ground surface of a temperate deciduous forest over an annual cycle using the eddy covariance technique. Over a year, the net radiation at the forest floor was 21.5% of that above the canopy, but this proportion was not constant, primarily because of the distinct phenological …
Journal: Agricultural And Forest Meteorology, Volume 102 (2-3): 83-103 (2000). DOI: 10.1016/s0168-1923(00)00124-6 Sites: US-WBW
The components of the surface energy balance were measured for 3 years over a broadleaved deciduous forest using the eddy covariance technique. Within years, the magnitude and distribution of fluxes was controlled by seasonal changes in solar radiation, drought, as well as leaf emergence and senescence. Evapotranspiration increased …
Journal: Agricultural And Forest Meteorology, Volume 100 (1): 1-18 (2000). DOI: 10.1016/s0168-1923(99)00088-x Sites: US-WBW
We used gas exchange techniques to estimate maximum rate of carboxylation (Vcmax), a measure of photosynthetic capacity, in the understory and upper crown of a closed deciduous forest over two seasons. There was extensive variability in photosynthetic capacity as a result of vertical canopy position, species type, …
Journal: Tree Physiology, Volume 20 (9): 565-578 (2000). DOI: 10.1093/treephys/20.9.565 Sites: US-WBW
Forest biomes are major reserves for terrestrial carbon, and major components of global primary productivity. The carbon balance of forests is determined by a number of component …
Journal: Plant, Cell And Environment, Volume 22 (6): 715-740 (1999). DOI: 10.1046/j.1365-3040.1999.00453.x Sites: CA-Obs, US-WBW
The combination of isotopic measurements and micrometeorological flux measurements is a powerful new approach that will likely lead to new insight into the dynamics of CO2 exchange between terrestrial …
Journal: Global Biogeochemical Cycles, Volume 13 (4): 903-922 (1999). DOI: 10.1029/1999gb900072 Sites: US-WBW
How eco-physiological, biogeochemical and micrometeorological theory can be used to compute biosphere–atmosphere, trace gas exchange rates is discussed within the framework of a process model. The accuracy of the theory is tested by comparing computations of mass and energy flux densities (water vapor, sensible heat, CO2 …
Journal: Agricultural And Forest Meteorology, Volume 90 (1-2): 1-25 (1998). DOI: 10.1016/s0168-1923(97)00072-5 Sites: US-WBW