Dimension analysis, acetylene reduction and canopy structure measurements were used to evaluate the relationship between density and dry weight production, nitrogen (N₂) fixation and photosynthate partitioning (as indicated by dimension analysis) in 5-year-old red alder (Alnus rubra Bong.) plantations established at three initial spacings. Density strongly affected most dry weight...
Analysis of import trade since 1976 shows that forests of the Pacific Northwest provide
Japan with the largest share of pine mushrooms (Tricholoma spp.) outside of East Asia.
To determine whether North American pine mushrooms (Tricholoma magnivelare (Peck)
Redhead) merit more intensive management in the southern Cascade Range, a major...
Maritime cyclonic windstorms cause widespread disturbance to forested ecosystems in southeast Alaska. The consequence of this disturbance process on the movement, storage, and quality of soil carbon, forest hydrology and streamwater chemistry was studied along a windthrow disturbance sequence. Soil profiles were described and the thickness of the major organic...
Soil effects from mountain beaver (Aplodontia rufa ) burrowing were
investigated in Oregon Coast Range soils formed from Tyee sandstone. The potential
for observed changes in soil to affect productivity was assessed. Soil horizons from
mountain beaver mound soil and adjacent unmounded profiles were collected with a
monolith-type quantitative sampler....
Remote sensing technologies have proven useful and cost-efficient for quantifying various forest vegetation characteristics over multiple scales. However, significant limitations were encountered in each of two related experiments conducted to explore their potential to supplement or replace traditional, single-species biomass equations for estimation of ground vegetation and tree overstory on...
Soil organic carbon (SOC, kg C m-2) is an important component in evaluating global C stores. The nitrogen (TN, kg N m"2) cycle is closely linked to C and understanding its role is also important. Contents and distributions of SOC and TN in soil profiles, to 1-meter depth, were estimated...
Though the mixed-evergreen forests of the Klamath Siskiyous have a long history of large, mixed-severity fires, most research in this region has concentrated on the impacts of high-severity fire. Knowledge of the ecological effects of low- and moderate-severity areas within mixed-severity fires is important because such areas may account for...
Stem growth, stem form development, and the dynamics of crown recession in young red alder (Alnus rubra Bong.) were studied by analyzing annual growth rings of stems and
knots, annual height increments, projected crown areas, and branch diameters. Forty-one
trees were sampled from three plantation spacing studies, representing ages 1...
Changes in soil C and N pools following wildfire are
quite varied, but there is little understanding of the
causes of the variation. We examined how the
legacies of prefire ecosystem structure may explain
the variation in soil trajectories during the first
decade following wildfire. Five years prior to
wildfire...
Full Text:
Prefire Ecosystem Structure in
Douglas-Fir Forest
Peter S. Homann,1* BernardT. Bormann,2 Brett A
Soil is an important, dynamic component of regional and global mercury (Hg) cycles. This study evaluated how changes in forest soil Hg masses caused by atmospheric deposition and wildfire are affected by forest structure. Pre and postfire soil Hg measurements were made over two decades on replicate experimental units of...
Changes in soil C and N pools following wildfire are
quite varied, but there is little understanding of the
causes of the variation. We examined how the
legacies of prefire ecosystem structure may explain
the variation in soil trajectories during the first
decade following wildfire. Five years prior to
wildfire...
Changes in soil C and N pools following wildfire are quite varied, but there is little understanding of the causes of the variation. We examined how the legacies of prefire ecosystem structure may explain the variation in soil trajectories during the first decade following wildfire. Five years prior to wildfire...
Early-successional stages have been truncated and altered in many western U.S. forest landscapes by
planting conifers, controlling competing vegetation, suppressing fire, and focusing on maintaining late-seral
species and undisturbed riparian zones. Declining area of early-successional stages may be reducing
resilience and sustainability on landscapes that experience elevated disturbance related to...
Full Text:
@earthlink.net (S.N. Little).
1 Present address: Retired, Portland, OR, United States.
BernardT. Bormann a
Early-successional stages have been truncated and altered in many western U.S. forest landscapes by
planting conifers, controlling competing vegetation, suppressing fire, and focusing on maintaining late-seral
species and undisturbed riparian zones. Declining area of early-successional stages may be reducing
resilience and sustainability on landscapes that experience elevated disturbance related to...
Full Text:
for biodiversity and long-term productivity of
conifer forests in southwestern Oregon
BernardT
Early-successional stages have been truncated and altered in many western U.S. forest landscapes by planting conifers, controlling competing vegetation, suppressing fire, and focusing on maintaining late-seral species and undisturbed riparian zones. Declining area of early-successional stages may be reducing resilience and sustainability on landscapes that experience elevated disturbance related to...
T cells are one of the key cells in the immune system. Although they are not the first line of defense against a pathogen, their functions can greatly enhance the phagocytosis and destruction of pathogens as well as the development of antibody responses. Furthermore, even when responding T cells have...
Previous work at Stanford University has demonstrated that inductance in the
substrate connection is the principal problem underlying the coupling of digital
switching noise into analog circuits. The low impedance substrate can be treated
as a single node over a local area. Switching in the digital circuits produces
current transients...