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). 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). 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). 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). DOI: 10.1111/j.1365-2486.1996.tb00071.x Sites: US-WBW
Fluxes of carbon dioxide, water vapor and energy were measured above and below a temperate broad-leaved forest and a boreal jack pine (Pinus banksiania Lamb.) forest by the eddy covariance method. The aim of the work was to examine differences between the biological and physical processes that control the fluxes of mass …
Journal: Tree Physiology, Volume 16 (1-2): 5-16 (1996). DOI: 10.1093/treephys/16.1-2.5 Sites: US-WBW
High rural concentrations of ozone (O3) are thought to be either stratospheric in origin, advected from upwind urban sources, or photochemically generated locally as a result of natural trace gas emissions. Ozone is known to be transported vertically downward from the above-canopy atmospheric surface layer and destroyed …
Journal: Geophysical Research Letters, Volume 23 (8): 841-844 (1996). DOI: 10.1029/96gl00786 Sites: US-GBT
Journal: Science, Volume 271 (5255): 1576-1578 (1996). DOI: 10.1126/science.271.5255.1576 Sites: US-Ha1
This paper reports the results of the analysis of CO2 exchange from a one-month experiment conducted at a mixed deciduous forest, Camp Borden (80°65′W, 44°19′ N), Canada, in the summer of 1993. The mid-day CO2 flux from the forest under clear sky conditions was around −1.0 mg m−2 …
Journal: Agricultural And Forest Meteorology, Volume 81 (1-2): 13-29 (1996). DOI: 10.1016/0168-1923(95)02310-0 Sites: CA-Cbo