Seven years of carbon dioxide flux measurements indicate that a ∼90-year-old spruce dominated forest in Maine, USA, has been sequestering 174±46 g C m−2 yr−1 (mean±1 standard deviation, nocturnal friction velocity (u*) threshold >0.25 m s−1). An analysis of monthly …
Journal: Global Change Biology, Volume 10 (10): 1689-1706 (2004), ISBN . DOI: 10.1111/j.1365-2486.2004.00847.x Sites: US-Ho1
Sources and sinks of carbon associated with forests depend strongly on the management regime and spatial patterns in potential productivity. Satellite remote sensing can provide spatially explicit information on land cover, stand-age class, and harvesting. …
Journal: Environmental Management, Volume 33 (4): 457-466 (2004), ISBN . DOI: 10.1007/s00267-003-9103-8 Sites: US-Me4, US-Me5
Underestimation of nocturnal CO2 respiration under calm conditions remains an unsolved problem at many forest flux stations. In this paper, the hypothesis is tested that horizontal mean transport, not previously measured, may account for the missing CO2. A systematic methodology was developed that comprises …
Journal: Agricultural And Forest Meteorology, Volume 122 (3-4): 139-156 (2004), ISBN . DOI: 10.1016/j.agrformet.2003.09.011 Sites: US-Ha1
In this paper, a model is presented for scalar advection inside canopies. A key result is an advection/diffusion equation that captures the persistence effect of the diffusion plume from elevated sources through a near-field modifier. The model is applicable to various source configurations including line source, plane and …
Journal: Agricultural And Forest Meteorology, Volume 127 (3-4): 131-141 (2004), ISBN . DOI: 10.1016/j.agrformet.2004.07.009 Sites: US-GMF
Hourly observations of forest-atmosphere energy balance components are presented for the Morgan-Monroe State Forest, south-central Indiana, USA for the period March 1998 to December 2001, with particular emphasis on the storage heat flux (ΔQS). The sub-components of ΔQS showed strong diurnal …
Journal: Agricultural And Forest Meteorology, Volume 126 (3-4): 185-201 (2004), ISBN . DOI: 10.1016/j.agrformet.2004.07.003 Sites: US-MMS
Humans have altered the global and regional cycles of nitrogen more than any other element. Alteration of N cycling patterns and processes in forests is one potentially negative outcome of accelerated N deposition worldwide. To assess potential impacts of N deposition on temperate forests, a series of chronic nitrogen additions …
Journal: Forest Ecology And Management, Volume 196 (1): 7-28 (2004), ISBN . DOI: 10.1016/j.foreco.2004.03.033 Sites: US-Ha2, US-LPH
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-Me2
We tested the hypothesis that the stable carbon isotope signature of ecosystem respiration (δ13CR) was regulated by canopy conductance (Gc) using weekly Keeling plots (n=51) from a semiarid old-growth ponderosa pine (Pinus ponderosa) forest in Oregon, USA. For …
Journal: Global Change Biology, Volume 10 (10): 1767-1784 (2004), ISBN . DOI: 10.1111/j.1365-2486.2004.00837.x Sites: US-Blo, US-Me4
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