The objectives of this investigation were to measure the seasonal and diurnal variations of starch as well as to relate these variations to growth of the trees. This study also microscopically examined the
needles to determine if starch exists in granular form in Douglas-fir. The objectives were designed to gain...
This study characterized the nature and dynamics of interference in mixed red alder
(Alnus rubra Bong.)/Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) stands in the Pacific Northwest, USA. Long-term spatial and tree measurements from the Cascade Head (CH) and H.J. Andrews (HJA) Experimental Forests in western Oregon and Delezene Creek (DC), Washington...
Salal is plant species that is native to forestland throughout the PNW and northern California that has been identified as a competitor to early crop tree development. This study consisted of a field and a radioisotope laboratory study to test four commonly used herbicides on salal (imazapyr, triclopyr, glyphosate, and...
This dissertation investigated the impacts of tree height upon a range of physiological and structural characteristics of Douglas-fir foliage; relationships between structural and functional trends with height; and compensatory mechanisms that mitigate height-related growth constraints. Height-related trends in foliar physiological and anatomical characteristics were examined both within trees as well...
Commercial thinning operations can result in damage to residual stems. A literature review revealed that little was known about the effects of residual logging wounds with regard to rotation-age commercial conifers, particularly Douglas-fir. An experiment to examine fungal colonization of Douglas-fir following logging damage showed that while damage was significant...
Atmospheric carbon dioxide levels have been steadily increasing from anthropogenic energy production, development and use. Carbon cycling in the terrestrial biosphere, particularly forest ecosystems, has an important role in regulating atmospheric concentrations of carbon dioxide. US West coast forest management policies are being developed to implement forest bioenergy production while...
Methods for obtaining accurate, spatially explicit estimates of biomass density in tropical forests are required to reduce uncertainties in the global carbon cycle, and to support international climate agreements and emerging carbon markets. Three-dimensional (3-D) remote sensing techniques sensitive to the vertical structure of vegetation provide a unique opportunity for...
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2.10 Stand biomass versus measurement (σM), allometric (σA and σS), and co-
location (σC) errors
As concern over global warming intensifies, sequestration and storage of atmospheric CO2 has become an important scientific and policy issue. Confusion persists, however, over interpretation of forest carbon (C) source-sink dynamics, in part because conclusions drawn depend on temporal and spatial scales of analysis (e.g. day-week
scale vs. successional-scale), type...
The link between aboveground net primary productivity (ANPP) and resource gradients generated by complex terrain (solar radiation, nutrients, and moisture) has been established in the literature. Belowground ecosystem stocks and functions, such as soil organic carbon (SOC), dissolved organic carbon (DOC), and belowground productivity have also been related to the...
The structure and composition of mixed-conifer forest (MCF) in central Oregon has been altered by fire exclusion and logging. The resulting increased density, spatial contagion, and loss of fire resistant trees decrease the resiliency of this ecosystem to fire, drought, and insects. The historical and current composition and structure of...