Classification of Streams and stream habitats is useful for research involving establishment of monitoring stations, determining local impacts of land use practices, generalization from site-specific data, and assessment of basin-wide, cumulative impacts of human activities on streams and their biota. This thesis presents a framework for a hierarchical classification system,...
The purpose of this study was to describe the life cycles,
feeding ecology, and habitat use of western species in the mayfly
family Ephemerellidae. Data were used to compare the ecological
relationships and strategies among species and to examine patterns
of adaptive radiation within the family. Data were further used...
The morphology and ecological importance of habitats associated with the margin of third-order stream channels in the Oregon Cascades were studied in streams in three different riparian types: 450-year-old conifers, 40-year-old alder, and an open, herbaceous-dominated clearcut. Margins, backwaters, and side channels in streams create important habitat for fry of...
Sampling error associated with estimates of species composition and age composition
of commercial groundfish landings in Oregon from 1989 to 1991 is documented to evaluate
the impact of variable landing data on fisheries management and monitoring programs. The
statistical reliability and bias associated with two multistage sampling designs are
investigated...
Fishermen's and managers' perceptions of fishery issues are an
important factor to consider when studying conflicts between the
two groups. According to theories of conflict management,
differences in perceptions may cause situations to be characterized
by misunderstanding and mistrust, and may add to the difficulties in
managing the conflict.
A...
The purpose of this study was to document the life
history of the xylophagous elmid beetle, Lara avara. and to
estimate its contribution to wood degradation in Oregon
streams. Field collections, mark-recapture, and laboratory
rearing were used to determine details of the life cycle.
Laboratory feeding studies and field population...
Studies of the effects of forest harvest on streams and fish have a long history in the Pacific Northwest. Results of this work have prompted development of new forest harvest practices that are more protective of these resources, but the effectiveness of these new practices has not been fully evaluated....
The objectives of this study were to (1) describe
physical environmental conditions and species composition
at several sites along an Upstream/downstream gradient in a
number of tributaries of the Willamette River in western
Oregon; and (2) identify possible relationships between
species distributional patterns and physical habitat
parameters using detrended correspondence...
The stability of a limpet-dominated community was
assessed in a experiment in which an consumer was
temporarily removed. Compared to unmanipulated plots,
the limpet-exclusion plots developed greater algal
abundance and altered species composition of both algae
and barnacles. The community was not perturbed beyond
its capacity to recover, since the...