The goal of this study was to describe the duration and magnitude of the physiological stress response in lingcod Ophiodon elongatus after exposure to brief handling and sublethal air stressors. The response to these stressors was determined during a 24‐h recovery period by measuring concentrations of plasma cortisol, lactate, glucose,...
Radioactive In has been incorporated into oriented thin films of YBa₂Cu₃O₇₋δ during a thermal coevaporation process. The hyperfme technique of perturbed γγ-angular correlation spectroscopy shows that 60% of the indium substitutes at a single site in the superconductor. We obtain spectra with reasonable statistics from 2 mCi of starting material,...
Stratified seeds of coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) were germinated, sown in soil, and seed coats and megagametophytes were removed at various stages of early seedling development. Yield and quality of DNA extracted from the megagametophytes were related to several morphological traits of the seedlings after
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Contributions of sites, rootstocks, and scion clones (and the nteractions between these factors) to scion growth and reproduction were studied in loblolly pine (Pinus taeda L.). Twenty-five full-sib families were used as rootstocks. Six scion clones were grafted on them in all combinations. Study sites were three seed orchards in...
When grown together in plantations, fast-growing southern and coastal sources of loblolly pine (Pinus taeda L.)often have lower wood specific gravity than northern and inland sources. This study investigated whether this phenomenon could be explained by a later transition to latewood, associated with a longer period of height growth, of...
Pollen contamination was investigated in one block (block 4) of a 10-block Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed orchard complex in western Oregon. Blocks (25 clones each) represent different breeding zones; thus, contaminant pollen sources not only included the adjacent natural stand of Douglas-fir, but also other blocks within the...
Mortality from Armillaria root rot is a major concern of forest management. Field experiments were conducted in Minnesota to evaluate interspecific differential susceptibility and to assess whether density or species composition, specifically the proportion of conifers in a plot, influences seedling mortality from Armillaria spp. Seedlings of 10 tree species...
The effects of prescribed underburning on soil total C pools, total and inorganic N pools, and in situ net N mineralization were examined during a 1-year study in ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) sites that had been experimentally burned 4 months, 5 years, or 12...
Many species of Populus, particularly cottonwoods of sections Aigeiros and Tacamahaca, remain recalcitrant to genetic transformation. We demonstrate that transgenic trees can be readily produced in several poplar genotypes using wild-type Agrobacterium rhizogenes. Hairy roots were produced in a variety of clones that included Populus trichocarpa Torr. & A. Gray,...
Seedlings of Pseudotsuga menziesii (Mirb.) Franco and Betula papyrifera Marsh. were grown in the greenhouse in monoculture and dual culture in soils collected from a young mixed species plantation in the southern interior of British Columbia. The objectives of the study were (i) to evaluate the ability of P. menziesii...
Nitrogen incorporation from red alder (Alnus rubra Bong.) into an Oregon upland mesic forest soil was studied by tracing the fate of 15N added as 15N-labeled alder leaf litter. The recovery of 15N in vegetation, litter, light- and heavy-fractions of the soil, the chloroform-labile (microbial biomass) pool, and the whole...
Substrate respiration, mineralizable nitrogen, and nitrogen fixation rates, substrate moisture content, and temperature were measured in trenched and undisturbed plots within two western Oregon Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands. The stands represent two different environments and ages. Woods Creek, the site of the lower elevation mature 70-year-old stand, is...
Canopy architectures of five structurally complex forest stands and three structurally simple forest stands in southwest Oregon and the Willamette Valley, Oregon, were evaluated and quantified through crown area profiles. Mixed conifer and mixed conifer-hardwood stands across a range of sites were sampled for crown widths and heights. Crown width...
The efficiency of six disaggregative methods and two individual-tree methods was evaluated in terms of their ability to predict 5-year basal area increment for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in western Oregon. Models were developed for predicting gross stand basal-area increment and individual-tree diameter increment. In addition, models were...
The amount and type of carbon (C) in a forest soil reflects the past balance between C accumulation and loss. In an old-growth forest soil, C is thought to be in dynamic equilibrium between accumulations and losses. Disturbance upsets this equilibrium by altering the microclimate, the amount and type of...
To consider the regional scale effects of forest management requires complete and consistent data over large areas. We used Landsat Thematic Mapper and Multispectral Scanner (TM and MSS) imagery to map forest cover and detect major disturbances between 1975 and 1992 for a 4.2 x 106 ha area of interior...
We studied the ages and diameter growth rates of trees in former Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) old-growth stands on 10 sites and compared them with young-growth stands (50-70 years old, regenerated after timber harvest) in the Coast Range of western Oregon. The diameters and diameter growth rates for the...
Sequence data from nrITS and cpDNA have failed to fully resolve phylogenetic relationships among Pinus species. Four low‐copy nuclear genes, developed from the screening of 73 mapped conifer anchor loci, were sequenced from 12 species representing all subsections. Individual loci do not uniformly support either the nrITS or cpDNA hypotheses...
Organellar DNA sequences are widely used in evolutionary and population genetic studies, however, the conservative nature of chloroplast gene and genome evolution often limits phylogenetic resolution and statistical power. To gain maximal access to the historical record contained within chloroplast genomes, we have adapted multiplex sequencing-by-synthesis (MSBS) to simultaneously sequence...
Longitudinal growth strains develop in woody tissues during cell-wall formation. This study compares stems, which have a mechanical role and experience longitudinal stresses, and nonstructural roots, which have little mechanical role and experience few or no longitudinal stresses, to test the hypothesis that growth strains are produced in stems of...