In coastal forests of the Pacific Northwest, young coniferous plantations typically contain a mixture of planted and natural Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla). Swiss needle cast (SNC) disease inhibits the growth of Douglas-fir to varying degrees in these stands, depending on SNC severity. In addition to the...
Knowledge about the relationship between habitat structure and abundance of a target species
facilitates biodiversity conservation in managed forests. However, modeling the relationship
for infrequent small mammal species in silvicultural experiments introduces the challenge of
excessive zero counts and complex hierarchical sampling. A common solution has been to
ignore infrequent...
An inertial subrange was found in spectra calculated from vertical profiles of temperature gradient recorded in the bottom boundary layer of the Oregon shelf. Spectra were calculated for 53-cm vertical segments. An ensemble average of those spectra that were fully resolved and had high Cox number was compared to the...
Slow perturbations of the drop speed of a nearly freely falling, winged, microstructure probe in the upper
200 m at station P are interpreted as vertical velocity fluctuations of an internal wave field. The frequencies of these fluctuations lie in the 2.5- to 4-cph band, near the buoyancy-frequency cutoff. A...
Distributed temperature data are used as input and
as calibration data for an energy based temperature model
of a first order stream in Luxembourg. A DTS (Distributed
Temperature Sensing) system with a fiber optic cable of
1500m was used to measure stream water temperature with
1m resolution each 2 min....
Observations of vertical temperature microstructure at ocean station P during the mixed layer experiment (Mile) indicate that the shape of the high-frequency temperature gradient spectrum depends on the relative strengths of turbulence and stratification. For low Cox number ((dT/dz)²)/ (dT/dz)²• the linear range of the Batchelor spectrum is not well...
The dynamic nature of biological hotspots, while well recognized, is not well understood. We hypothesize that the persistence of hotspots in the northern California Current System (CCS), despite seasonal and annual changes in the nekton community species composition, is related to associations among species and their functional redundancy. To address...
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...
Pole-size Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were inoculated with two fungi (Ophiostoma pseudotsugae (Rumb.) von Arx and Leptographium abietinum (Peck) Wingf.) associated with the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) to evaluate their pathogenicity. Pruning the lowermost 30% of the live crown had no
effect on host tree defenses. Inoculation with...
The width of earlywood and latewood in conifer xylem may have a profound effect on water transport and storage, vulnerability to embolism, and wood strength, yet the controls over the timing of latewood formation are unclear. Tracheids differentiating in the cambial zone are influenced by IAA indole-3 acetic acid, the...