Publications

Publications Found: 1437

Groundwater Flow Patterns In A Large Peatland
Fraser, C., Roulet, N., Lafleur, M.

Groundwater flow patterns and geochemistry were studied in the Mer Bleue bog, near Ottawa, Ontario, Canada. Groundwater flow patterns alternated between recharge, i.e. head gradients producing flow from the surface of the peatland to the deeper peat, and discharge, i.e. head gradients indicating flow from the deeper peat …


Journal: Journal Of Hydrology, Volume 246 (1-4): 142-154 (2001). DOI: 10.1016/s0022-1694(01)00362-6 Sites: CA-Mer

Carbon Dioxide And Water Vapor Exchange By Young And Old Ponderosa Pine Ecosystems During A Dry Summer
Law, B. E., Goldstein, A. H., Anthoni, P. M., Unsworth, M. H., Panek, J. A., Bauer, M. R., Fracheboud, J. M., Hultman, N.

We investigated key factors controlling mass and energy exchange by a young (6-year-old) ponderosa pine (Pinus ponderosa Laws.) plantation on the west side of the Sierra Nevada Mountains and an old-growth ponderosa pine forest (mix of 45- and 250-year-old trees) on the east side of the Cascade Mountains, from June through …


Journal: Tree Physiology, Volume 21 (5): 299-308 (2001). DOI: 10.1093/treephys/21.5.299 Sites: US-Me4, US-Me5

Paired-Tower Measurements Of Carbon And Energy Fluxes Following Disturbance In The Boreal Forest
Amiro, B. D.

Disturbances by fire and harvesting are thought to regulate the carbon balance of the Canadian boreal forest over scales of several decades. However, there are few direct measurements …


Journal: Global Change Biology, Volume 7 (3): 253-268 (2001). DOI: 10.1046/j.1365-2486.2001.00398.x Sites: CA-SF2, CA-SF3

Spatial And Seasonal Variability Of Photosynthetic Parameters And Their Relationship To Leaf Nitrogen In A Deciduous Forest
Wilson, K. B., Baldocchi, D. D., Hanson, P. J.

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

The Controls On Net Ecosystem Productivity Along An Arctic Transect: A Model Comparison With Flux Measurements
Williams, M., Eugster, W., Rastetter, E. B., Mcfadden, J. P., Chapin, F. S.

Assessments of carbon (C) fluxes in the Arctic require detailed data on both how and why these fluxes vary across the landscape. Such assessments are complicated because tundra vegetation has diverse structure and function at both local and regional scales. To investigate this diversity, the Arctic Flux Study has used the eddy covariance …


Journal: Global Change Biology, Volume 6 (S1): 116-126 (2000). DOI: 10.1046/j.1365-2486.2000.06016.x Sites: US-Upa

On Measuring And Modeling Energy Fluxes Above The Floor Of A Homogeneous And Heterogeneous Conifer Forest
Baldocchi, D. D., Law, B. E., Anthoni, P. M.

Information on mass and energy exchange at the soil surface under vegetation is a critical component of micrometeorological, climate, biogeochemical and hydrological models. Under sparse boreal and western conifer forests as much as 50% of incident solar energy reaches the soil surface. How this energy is partitioned into …


Journal: Agricultural And Forest Meteorology, Volume 102 (2-3): 187-206 (2000). DOI: 10.1016/s0168-1923(00)00098-8 Sites: CA-Ojp, US-Me4

Effects Of Forest Harvesting On Soil Methane Fluxes In Florida Slash Pine Plantations
Castro, M. S., Gholz, H. L., Clark, K. L., Steudler, P. A.

We examined the effects of forest harvesting on the net exchange of methane (CH4) between the atmosphere and sandy soils in two mature slash pine (Pinus elliottii Engelm. var. elliottii) plantations in northern Florida. Before each of the stem-only harvests, soils in these plantations were net sinks for CH4


Journal: Canadian Journal Of Forest Research, Volume 30 (10): 1534-1542 (2000). DOI: 10.1139/cjfr-30-10-1534 Sites: US-SP1, US-SP2, US-SP3, US-SP4

Measuring And Modelling Seasonal Variation Of Carbon Dioxide And Water Vapour Exchange Of A Pinus Ponderosa Forest Subject To Soil Water Deficit
Law, B. E., Williams, M., Anthoni, P. M., Baldocchi, D. D., Unsworth, M. H.

We conducted ecosystem carbon and water vapour exchange studies in an old-growth Pinus ponderosaforest in the Pacific North-west region of the United States. The canopy is heterogeneous, with tall multiaged trees and an open, clumped canopy with low leaf area. Carbon assimilation can occur throughout relatively mild winters, …


Journal: Global Change Biology, Volume 6 (6): 613-630 (2000). DOI: 10.1046/j.1365-2486.2000.00339.x Sites: US-Me5

Estimating Watershed Evapotranspiration With Pass. Part I: Inferring Root-Zone Moisture Conditions Using Satellite Data
Song, J., Wesely, M. L., Coulter, R. L., Brandes, E. A.

A model framework for parameterized subgrid-scale surface fluxes (PASS) has been modified and applied as PASS1 to use satellite data, models, and limited surface observations to infer root-zone available moisture (RAM) content with high spatial resolution over large terrestrial areas. Data collected during the 1997 Cooperative Atmosphere–Surface …


Journal: Journal Of Hydrometeorology, Volume 1 (5): 447-461 (2000). DOI: 10.1175/1525-7541(2000)001<0447:EWEWPP>2.0.CO;2 Sites: US-Wlr

Remote Sensing Of Photosynthetic-Light-Use Efficiency Of Boreal Forest
Nichol, C. J., Huemmrich, K. F., Black, T., Jarvis, P. G., Walthall, C. L., Grace, J., Hall, F. G.

Using a helicopter-mounted portable spectroradiometer and continuous eddy covariance data we were able to evaluate the photochemical reflectance index (PRI) as an indicator of canopy photosynthetic light-use efficiency (LUE) in four boreal forest species during the Boreal …


Journal: Agricultural And Forest Meteorology, Volume 101 (2-3): 131-142 (2000). DOI: 10.1016/s0168-1923(99)00167-7 Sites: CA-Man, CA-Oas, CA-Obs, CA-Ojp