Measurements of the fluxes of latent heat λE, sensible heat H, and CO2 were made by eddy covariance in a boreal black spruce forest as part of the Boreal Ecosystem-Atmosphere Study (BOREAS) for 120 days through the growing season in 1994. BOREAS is a multiscale study in which satellite, airborne, stand-scale, …
Journal: Journal Of Geophysical Research: Atmospheres, Volume 102 (D24): 28953-28966 (1997), ISBN . DOI: 10.1029/97jd01176 Sites: CA-Obs
Journal: Tree Physiology, Volume 17 (8-9): 491-499 (1997), ISBN . DOI: 10.1093/treephys/17.8-9.491 Sites: CA-Man, CA-Oas, CA-Obs, CA-Ojp
The objectives of this study are to (1) characterize the carbon (C) content, leaf area index, and aboveground net primary production (ANPP) for mature aspen, black spruce, and young and mature jack pine stands …
Journal: Journal Of Geophysical Research: Atmospheres, Volume 102 (D24): 29029-29041 (1997), ISBN . DOI: 10.1029/97jd02317 Sites: CA-Man
We compared vertical gradients in leaf gas exchange, CO2 concentrations, and refixation of respired CO2 in stands of Populus tremuloides Michx., Pinus banksiana Lamb. and Picea mariana (Mill.) B.S.P. at the northern and southern boundaries of the central Canadian boreal forest. Midsummer …
Journal: Tree Physiology, Volume 17 (1): 1-12 (1997), ISBN . DOI: 10.1093/treephys/17.1.1 Sites: CA-Man, CA-Oas, CA-Obs, CA-Ojp
We monitored sap flow and estimated diurnal changes in transpiration rates of two trembling aspen (Populus tremuloides Michx.) stands, located in the southern boreal forest and aspen parkland of Saskatchewan, Canada. In both stands during the peak growing season (June and July), sap flow during the day (0700–1700 h local …
Journal: Tree Physiology, Volume 17 (8-9): 501-509 (1997), ISBN . DOI: 10.1093/treephys/17.8-9.501 Sites: CA-Oas
Temperate deciduous forests exhibit dramatic seasonal changes in surface exchange properties following on the seasonal changes in leaf area index. Nearly continuous measurements of turbulent and radiative fluxes above and below the canopy of a red oak forest in central Massachusetts have been ongoing since the summer of 1991. Several …
Journal: Journal Of Applied Meteorology, Volume 35 (1): 122-134 (1996), ISBN . DOI: 10.1175/1520-0450(1996)035<0122:SVIRAT>2.0.CO;2 Sites: US-Ha1
The turbulent exchanges of CO2 and water vapour between an aggrading deciduous forest in the north-eastern United States (Harvard Forest) and the atmosphere were measured from 1990 to 1994 using the eddy covariance technique. We present a detailed description of the methods used and a rigorous evaluation of the precision …
Journal: Global Change Biology, Volume 2 (3): 169-182 (1996), ISBN . DOI: 10.1111/j.1365-2486.1996.tb00070.x Sites: US-Ha1
Our objective was to measure the carbon isotope ratio of CO2 released by respiration (δr) within forest canopies at different times during the growing season and to use this information to estimate forest ecosystem carbon isotope discrimination. We made measurements in the three major forest types (black spruce, …
Journal: Global Biogeochemical Cycles, Volume 10 (4): 629-640 (1996), ISBN . DOI: 10.1029/96gb02345 Sites: CA-Let
The degradation of soil aggregates appears to be a primary mechanism in the loss of organic matter caused by long-term cultivation, but little information exists on how the formation and stabilization of macroaggregates control the process of C aggradation when disturbance is reduced or eliminated. A chronosequence of restored tallgrass …
Journal: Soil Biology And Biochemistry, Volume 28 (4-5): 665-676 (1996), ISBN . DOI: 10.1016/0038-0717(95)00159-x Sites: US-IB1, US-IB2
Long-term and direct measurements of CO2 and water vapour exchange are needed over forested ecosystems to determine their net annual fluxes of carbon dioxide and water. Such measurements are also needed to parameterize and test biogeochemical, ecological and hydrological assessment models. Responding to this need, eddy …
Journal: Global Change Biology, Volume 2 (3): 183-197 (1996), ISBN . DOI: 10.1111/j.1365-2486.1996.tb00071.x Sites: US-WBW