The role of detritivores in the conversion of allochthonous
leaf material in two small streams in the Cascade Range of Oregon
was studied. Their importance in relation to other consumers was
estimated from emergence and benthic standing crop data.
Ingestion rates and efficiencies of utilization of bigleaf maple
(Acer macrophyllum)...
The ³²P material balance method for measuring periphyton production and grazing rates on periphyton in streams developed by Elwood and Nelson (1972) was evaluated by laboratory and field experiments. Three basic assumptions of the method were examined: 1) sloughing of periphyton from substrates is negligible, 2) sorption of ³²P onto...
The oxygen concentration in a stream is an important
parameter of water quality. Changes in oxygen concentrations
can affect various stream organisms including fish.
Foresters have become concerned with predicting the impacts
of forest activities on oxygen levels in streams. Slash,
which accumulates in streams as a result of harvesting...
The effects of sublethal concentrations of cyanide, pentachlorophenol and zinc individually and in combination on the growth and production of juvenile chinook salmon, Oncorhynchus tshawytscha (Walbaum), and aquatic invertebrates in model stream communities were studied in three experiments during 1971 and 1972 at the Oak Creek Fisheries Research Laboratory, Oregon...
Effects of current velocity, irradiance, and grazing on the
biomass, taxonomic structure, physiognomy, and chemical composition
of lotic algal assemblages were investigated. Four experiments,
lasting 32 to 75 days, were conducted in laboratory streams to
determine how these factors affect algal assemblages singly, and in
concert with each other.
Regardless...
Although there has been extensive research on the geomorphic and ecologic role of
large woody debris (LWD) in streams, the dynamics of LWD in streams are poorly
known due to various measurement difficulties during floods. In this thesis I present the
results of two flume experiments on the dynamics of...
Riparian zones are ecotones between terrestrial and aquatic ecosystems. Processes in streams are strongly influenced by riparian forest communities, age, stage and structure. Temperate forests across much of North America, including riparian areas, are recovering from historic land clearing with many stands in the stem-exclusion phase of development in which...
The protection of water quality and the maintenance of productive
anadromous fisheries is a primary concern in the Pacific Northwest.
Excessive suspended sediment loads is a principle water
quality problem on small wildland watersheds in this region (Anderson,
1971; Brown, 1972). Man's activities have been shown to increase
sedimentation rates...
This study investigates patterns of physical structure organization in stream
networks. In particular, it seeks to describe patterns of wood, boulders, pools and slope
that are evident in stream channels and to determine whether patterns of these elements
are influenced by network-level controls. The four in-stream parameters were
combined to...
Slow moving earthflows (0.1 15 m/yr.) may constrict valley
floors and directly impinge on stream channels. Earthflows that
move laterally into channels deliver organic and inorganic material
to the stream from the earthflow toe. If the amount and particle
size of this material is too large to be removed by...
