The eddy covariance technique provides valuable information on net ecosystem exchange (NEE) of CO2, between the atmosphere and terrestrial ecosystems, ecosystem respiration, and gross primary production (GPP) at a variety of CO2 eddy flux tower sites. In this paper, we develop a new, satellite-based Vegetation …
Journal: Remote Sensing Of Environment, Volume 89 (4): 519-534 (2004), ISBN . DOI: 10.1016/j.rse.2003.11.008 Sites: US-Ho1, US-Ho2, US-Ho3
We measured component and whole-system respiration fluxes in northern hardwood (Acer saccharumMarsh., Tilia americana L., Fraxinus pennsylvanica Marsh.) and aspen (Populus tremuloides Michx.) forest stands in Price County, northern Wisconsin from 1999 through 2002. Measurements of soil, leaf and …
Journal: Tree Physiology, Volume 24 (5): 493-504 (2004), ISBN . DOI: 10.1093/treephys/24.5.493 Sites: US-WCr
Mixing ratios of CO2 often change abruptly in the presence of inclement weather and low pressure systems. Water vapor mixing ratio, temperature, wind speed, and wind direction data are used to infer that the abrupt changes in CO2 mixing ratios at a site in northern Wisconsin are due to tropospheric mixing, horizontal …
Journal: Journal Of The Atmospheric Sciences, Volume 61 (5): 607-618 (2004), ISBN . DOI: 10.1175/1520-0469(2004)061<0607:TOCDIT>2.0.CO;2 Sites: US-PFa
Ground-based measurements of stores, growth, mortality, litterfall, respiration, and decomposition were conducted in an old-growth forest at Wind River Experimental Forest, Washington, USA. These measurements were used to estimate gross primary production (GPP) and net primary production (NPP); autotrophic respiration (Ra) …
Journal: Ecosystems, Volume 7: 498-512 (2004), ISBN . DOI: 10.1007/s10021-004-0140-9 Sites: US-Wrc
Discrepancies in closure of the surface energy balance is often an issue for many land surface types. The role of canopy storage terms from canopy water content and photosynthesis is usually neglected in the surface energy balance of crops. Data from a research flux tower …
Journal: Agricultural And Forest Meteorology, Volume 125 (1-2): 105-115 (2004), ISBN . DOI: 10.1016/j.agrformet.2004.03.001 Sites: US-Bo1, US-Bo2
Net primary production (NPP) was measured in seven black spruce (Picea mariana (Mill.) BSP)-dominated sites comprising a boreal forest chronosequence near Thompson, Man., Canada. The sites burned between 1998 and 1850, and each contained separate well- and poorly drained stands. All components of NPP were measured, most …
Journal: Global Change Biology, Volume 10 (4): 473-487 (2004), ISBN . DOI: 10.1111/j.1529-8817.2003.0742.x Sites: CA-Man, CA-NS2, CA-NS3, CA-NS5, CA-NS6, CA-NS7
The supply of water to the Nueces River Delta near Corpus Christi, Texas is limited by dams and channelization of the river which restrict freshwater inflow. The upper end (high marsh) of the delta frequently dries up during the summer. The marsh consists of slightly elevated islands containing emergent halophytes, and shallow ponds …
Journal: Agricultural And Forest Meteorology, Volume 125 (1-2): 159-172 (2004), ISBN . DOI: 10.1016/j.agrformet.2004.02.007 Sites: US-FR1, US-FR2, US-FR3
Uncertainty in biomass estimates is one of the greatest limitations to models of carbon flux in tropical forests. Previous comparisons of field-based estimates of the aboveground biomass (AGB) of trees greater than 10 cm diameter within Amazonia have been limited by the paucity of data for western Amazon forests, and the use of …
Journal: Global Change Biology, Volume 10 (5): 545-562 (2004), ISBN . DOI: 10.1111/j.1365-2486.2004.00751.x Sites: BR-Ma2, BR-Sa1, BR-Sa3
As forests age, their structure and productivity change, yet in some cases, annual rates of water loss remain unchanged. To identify mechanisms that might explain such observations, and to determine if widely different age classes of forests differ functionally, we examined young (Y, 25 years), mature (M, 90 years) …
Journal: Tree Physiology, Volume 24 (7): 753-763 (2004), ISBN . DOI: 10.1093/treephys/24.7.753 Sites: US-Me4, US-Me5
Synoptic monitoring of vegetation dynamics relies on satellite observations of the distinctive spectral contrast between red and near infrared reflectance that photosynthetically active green vegetation exhibits. It has long been recognized that the Normalized Difference Vegetation Index (NDVI) suffers a rapid decrease of sensitivity …
Journal: Geophysical Research Letters, Volume 31 (4): 1-4 (2004), ISBN . DOI: 10.1029/2003gl019034 Sites: US-Ne1, US-Ne2, US-Ne3