Effects of partial understory removal on belowground and aboveground ecosystem properties were investigated in 5 and 15 yr old Douglas-fir (Pseudotsuga menziesll (Mirb.) Franco) experimental plantations in western Oregon. Seedling survival was not affected by understory removal at age 5 yr.
But through age 15 yr, understory removal increased seedling...
Crater Lake National Park presents an excellent opportunity for ecological research due to its relatively pristine landscape, the protection of its natural features, its infrastructure, and a Park administration supportive of scientific inquiry and restoration ecology. The research presented here examines the responses of fungi to various forms of perturbation....
Soil organic matter levels, soil temperature and moisture, and vegetation properties were measured along a sequence of death and
regeneration in a mountain hemlock (Tsuga mertensiana) forest. The sequence is produced by slowly moving waves of the root pathogen Phellinus weirii. While analysis of variance for all sampled soil layers...
The Normalized Burn Ratio and Composite Burn Index were used to classify burn severity in three sites that experienced lightning-ignited wildfire in the year 2000. The effect of burn severity (unburned, low, moderate, and high severity classes) was investigated on vegetation and soil microbial community composition. Vegetation communities showed a...
In this study, biological and chemical characteristics were determined for two high-elevation meadow-to-forest transitions located in the Central Oregon Cascades. The chloroform fumigation incubation method (CFIM) was used to determine microbial biomass C(MBC) and the N flush due to fumigation (NF), and meadow values were compared to forest values for...
Seven case studies of 11 ecosystems were used to examine the effects of nitrogen-fixing alders in Douglas-fir plantations. The
first case study quantified nitrogen (N) fixation and aboveground net primary production in a young Sitka alder [Alnus sinuata (Regel) Rydb.] ecosystem. At 5 yr of age, the N fixation (C₂2H₂...
The effects of prescribed burning on the rates of recent litter
decomposition, nitrogen and phosphorus release from litter, soil total and
inorganic nitrogen pools, and net nitrogen mineralization were determined in
ponderosa pine sites that had been burned 0.3, 5 or 12 years earlier. Prescribed
burning decreased litter decomposition rates...
I used greenhouse and field studies to investigate how intraspecific and
interspecific competition, soil disturbance, and fertilization affect the biomass and
reproductive output of Senecio sylvaticus and Epilobium paniculatum, common winter
annuals which invade and dominate western Cascades forests during the first two seasons
after clearcutting and slashburning.
Field work...
The objective of this study was to determine how the
balance of carbon to nitrogen in a grand fir ecosystem affects
the chemistry of emerging grand fir foliage and the growth of
western spruce budworm larvae. Forest plots in the grand fir
zone of eastern Oregon were thinned, thinned and...
