Within the same forest, photosynthesis can vary greatly among species and within an individual tree. Quantifying the magnitude of variation in leaf-level photosynthesis in a forest canopy will improve our understanding of and ability to model forest carbon cycling. This information requires extensive sampling of photosynthesis in …
Journal: Oecologia, Volume 109 (4): 507-515 (1997), ISBN . DOI: 10.1007/s004420050111 Sites: US-Ha1
Effects of shoot water potential (Ψ) and leaf-to-atmosphere vapor pressure difference (VPD) on gas exchange of jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana (Mill.) B.S.P.), and aspen (Populus tremuloides Michx.) were investigated at the northern edge of the boreal forest in Manitoba, …
Journal: Tree Physiology, Volume 17 (8-9): 521-535 (1997), ISBN . DOI: 10.1093/treephys/17.8-9.521 Sites: CA-Man
Our objective was to evaluate the relative importance of gradients in light intensity and the isotopic composition of atmospheric CO2 for variation in leaf carbon isotope ratios within a Pinus resinosa forest. …
Journal: Oecologia, Volume 109 (4): 499-506 (1997), ISBN . DOI: 10.1007/s004420050110 Sites: CA-Mer
Recent evidence indicates that significant amounts of C may be lost as CO2 to the atmosphere from tundra ecosystems during the fall, winter and spring months. Because high latitude ecosystems are …
Journal: Global Biogeochemical Cycles, Volume 11 (2): 163-172 (1997), ISBN . DOI: 10.1029/96gb03035 Sites: US-HVa, US-Upa
Journal: Tree Physiology, Volume 17 (8-9): 553-561 (1997), ISBN . DOI: 10.1093/treephys/17.8-9.553 Sites: CA-Obs, CA-Ojp
Forests in the south-eastern United States experienced a prolonged dry spell and above-normal temperatures during the 1995 growing season. During this episode, nearly continuous, …
Journal: Plant, Cell And Environment, Volume 20 (9): 1108-1122 (1997), ISBN . DOI: 10.1046/j.1365-3040.1997.d01-147.x Sites: US-WBW
Fluxes of energy and water vapor over boreal forest stands are expected to vary during the growing season due to temporal variations in solar energy, soil and air temperature, soil moisture, photosynthetic …
Journal: Journal Of Geophysical Research: Atmospheres, Volume 102 (D24): 28939-28951 (1997), ISBN . DOI: 10.1029/96jd03325 Sites: CA-Ojp
Three independent methods were used to evaluate transpiration of a boreal forest: the branch bag, sap flow and eddy covariance methods. The branch bag method encloses several thousand needles and gives a continuous record of branch transpiration. The sap flow method provides a continuous record of sap velocity and an estimate of …
Journal: Tree Physiology, Volume 17 (8-9): 511-519 (1997), ISBN . DOI: 10.1093/treephys/17.8-9.511 Sites: CA-Obs
The energy balance components were measured throughout most of 1994 in and above a southern boreal aspen (Populus tremuloides Michx.) forest (53.629°N 106.200°W) with a hazelnut (Corylus cornuta Marsh.) understory as part of the Boreal Ecosystem-Atmosphere Study. The turbulent fluxes were measured at both levels …
Journal: Journal Of Geophysical Research: Atmospheres, Volume 102 (D24): 28915-28927 (1997), ISBN . DOI: 10.1029/97jd00193 Sites: CA-Oas
We measured stem respiration rates during and after the 1994 growing season of three common boreal tree species at sites near the northern and southern boundaries of the closed-canopy boreal forest in central Canada. The growth respiration coefficient (rg; carbon efflux per μmole of carbon incorporated in structural …
Journal: Tree Physiology, Volume 17 (8-9): 543-551 (1997), ISBN . DOI: 10.1093/treephys/17.8-9.543 Sites: CA-Man, CA-Oas, CA-Obs, CA-Ojp