This thesis describes a case study of the effects of five systems
of grazing on watershed values in a deteriorated riparian area. Soil
infiltration, bulk density and penetrability, streambank edge movement
and coliform bacteria were monitored for seven years along a stream
in the Blue Mountains of northeastern Oregon. For...
Riparian plant assemblages give clues of the conditions of the soil and other physical characteristics of their stream-side environment. The plight of the spring/summer, and fall Snake River chinook salmon has aroused interest in fish habitat and the effects of riparian plants on fish habitat. This study was launched to...
During summer and fall of 1981 to 1983, mark-recapture was
conducted in riparian and upland habitats within old-growth and
mature forests in the Cascade Range of Oregon. Number of
individuals and species richness were greater in riparian than
upland habitat. For most species, the mean adult weights and
the percentages...
Seasonal trends in water table level and soil moisture
for four plant community types within an irrigated eastern
Oregon riparian zone were described. Aboveground biomass,
species composition, litter, percent bareground and percent
basal cover of key plant species and life forms were measured.
The relationship between water table levels and...
The structure and components of riparian areas influence the rate, amount, and timing of water, nutrients, organic debris, and inorganic materials that enter streams and rivers. The energy of floodwaters and their ultimate volume, timing and erosive power is influenced by the soils, vegetation and geomorphology of fluvial surfaces within...
Wetlands of the Colorado Plateau that receive water from irrigation can, by their functions, support several societal values. For example, their capacity for removing nitrate and perhaps pesticides from nonpoint source runoff might be considerable. However, relatively little research has been conducted in irrigated wetlands, and their ability to alter...
This study examined the occurrence of coarse woody debris (i.e., pieces greater than 0.15 m in diameter and 2.0 m in length) in first- through fifth-order streams located within the Drift Creek Basin of the Oregon Coast
Range. Nine "tributary reaches" were surveyed to determine how three land management treatments...
As a key factor contributing to slope stability, in-stream habitat for aquatic species (e.g., salmonids), nutrient cycling, and corridors for upland species, riparian vegetation and its maintenance is of critical conservation importance. Subsequently, the chronic degradation of aquatic and riparian ecosystems in the semi-arid and arid landscapes of the western...
Managing riparian buffer zones is a potentially important approach to protecting streams from agricultural pollution. This study was conducted to determine if a pasture, a hybrid poplar (Populus trichocarpa x deltoides) stand, or a native oak (Quercus garryana) forest, had the greatest potential to serve as a nutrient buffer zone....
Little research has been directed toward determining the status and ecological role of riparian areas in agricultural landscapes of the Willamette Valley, Oregon. A research project has been designed to contribute to the development and evaluation of alternative future scenarios and to improve the basic understanding of the role of...
Riparian areas that can be used as reference sites on which to base goals of vegetation restoration have not been documented in the Oregon Coast Range. I examined the composition and distribution of unmanaged riparian overstories in the central Oregon Coast Range along nine streams which have experienced minimal disturbance...
Riparian zone vegetation can influence terrestrial and aquatic food webs through variations in the amounts, timing, and nutritional content of leaf and other litter inputs. Differences in vegetation composition and density, as well as riparian topography, may modulate the strength and quality of these inputs. Changes in inputs to small...
Organic matter dynamics in riparian ecosystems are largely driven by interactions among hydrology, soil, and vegetation. In two riparian meadows, northeast Oregon, I examined the hypothesis that vegetation and soil characteristics in three plant communities - defined as wet, moist, and dry meadow - were strongly influenced by hydrological and...
This study was conducted to describe variation of riparian vegetation in an Oregon Coast Range system according to geomorphic characteristics and in relation to streamflow. Specific objectives of this study were to: I) examine if the vegetation composition and structure of the riparian forest varied among channel-reach morphologies, 2) examine...
Large woody debris recruitment to streams from adjacent riparian forests influences stream
channel morphology, sediment routing, and fish habitat. A mathematical model was developed
to 1) determine whether the trees in a stand adjacent to a stream, upon falling, would provide
large woody debris of a specified size to the...
The purposes of this study were:1) to review the land use history of Oak Creek watershed since European settlement. And 2) to consider the human-caused impacts and their effects associated with different land uses. The study area was classified into three land use patterns: residential,agricultural, and forested areas.Since the European...
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...
Riparian vegetation (trees > 10 cm dbh), woody debris (> 10 cm diam, > 1 m long), channel, and landform characteristics were inventoried in mature (80-150 yrs) and old-growth riparian areas (>250 yrs) selected from small tributaries of the Coos and Coquille River basins in southwestern Oregon. Basal area of...
Riparian forests in the central Oregon Coast Range vary along a coniferous-deciduous compositional continuum. Variations in structure and composition affect water quality, fish and wildlife, biodiversity, timber, and aesthetics. A retrospective approach was taken in this study in order to understand and compare the structure, pattern, and history of an...
I studied riparian forests of four western Oregon watersheds (dry south to wet north) to determine the multiscale controls on woody riparian vegetation. I conducted separate analyses of controls on plant distribution, diversity, and tree regeneration using vegetation and environmental data collected in two related field studies: (1) a multiscale...
Riparian communities dominated by members of the
Salicaceae (Salix lasiandra, S. lutea, S. lemmonii,
Populus trichocarpa, P. tremuloides and S. exiqua) were
studied at the Crooked River National Grassland in central
Oregon. The objectives of this study were to examine the
relationships between the Salix and Populus species and
microsite...
Seasonal trends in forage production and environmental parameters
for five plant community types within a northeastern Oregon riparian zone
were described and modeled using correlation and path analysis. Wet
meadows produced the greatest amount of herbage biomass, followed by moist
bluegrass meadows, gravel bars, forests and dry bluegrass meadows. Trends...
Published January 1995. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Discusses what land use practices can impact riparian areas and the techniques landowners, volunteers, and professional resource managers can use to improve and protect riparian function.
Study objectives were to survey and compare physical and chemical characteristics of soils within two thirdorder montane riparian ecosystems: a 500-year old Douglas fir (Pseudotsuga menzlesii) forest at Mack Creek, and a mature red alder (Alnus rubra) forest occupying a 35-year old clearcut at Quartz Creek, both near Blue River,...
Two case studies were designed to study the effects of using off-stream water developments and water gap configurations to modify watering behavior of cattle. There were two objectives: 1) to evaluate an off-stream water source to reduce water quality impacts of grazing cattle on a mountain riparian zone during summer...
This publication is aimed at watershed councils, government agencies, and specialists (foresters, wildlife and fisheries biologists) interested in riparian area silviculture or watershed restoration. It contains information on the ecology of riparian forests and a checklist of recommended practices and common mistakes made in restoring conifers to hardwood-dominated riparian forests....
Riparian areas in the Pacific Northwest provide important biotic and abiotic
features, such as down wood, moist microsites, and abundant invertebrate prey that
benefit aquatic and terrestrial amphibians. Reported high densities of amphibians from
streams and riparian areas in the Pacific Northwest highlight their importance in riparian
food webs. Amphibians...
A multitude of biotic and physical factors, many of them unique to riparian environments, interacted to form an extremely complex ecosystem along Catherine Creek in the Wallowa Mountains. A total of 258 stands of vegetation representing 60 communities was identified. At least 20 species of mammals and 81 species of...
During 1988-1989, stream habitat variables were compared between beaver-dam sites and unoccupied-stream sites to identify variables that may have been important for beaver (Castor canadensis) in selecting dam sites in the streams of the Drift Creek basin, Lincoln County, Oregon. Increasing valley floor width and grass/sedge cover and decreasing stream...
Vegetation provides food for many insects, and many insects serve as food for bats. We investigated the linkages among these three trophic levels in riparian areas throughout the Oregon Coast Range by examining the influence of vegetation cover, composition, and structure on the activity of nocturnal insects and bats, the...
Streams make up only one percent of the watershed. Nonetheless, they are an essential component to watershed health. Streams are home to wildlife and fish. Well-functioning streams contribute to water quantity and quality. And streams play an important role in flood and erosion control.
This classification describes common streamside plant communities and the typical riparian settings in which they are found. The purpose of the guide is to allow an observer to interpret site factors from the vegetation, or to project potential plant community development from
key site factors. It should be useful in...
Two trials were conducted to evaluate changes in the quantity, quality, and moisture of available forage in the pasture, and shrub utilization by cattle during a 30-d late summer grazing period (Trial 1) and the effect of cow age (experience) on grazing distribution and diet composition (Trial 2) in mountain...
Salmonberry community structure was examined in alder-dominated
riparian buffer strips in the Oregon Coast Range. Salmonberry growing on slopes
was found to respond differently, to both characteristics of the buffer strips and
to environmental factors, than salmonberry growing on terraces.
Salmonberry, as measured by total height, number of ramets or...
Grazing of riparian forage by livestock may alter stream channel morphology in ways that impact nearby aquatic habitat, bank stability, vegetative cover and water quality. A number of grazing management practices have been proposed as a means to reduce the amount of time cattle spend in the riparian zone. The...
This study was designed and implemented to observe
the spatial and temporal dynamics of groundwater levels
and temperatures adjacent to a beaver pond in semi-arid
central Oregon. The study site was located on the eastern
boundary of Painted Hills National Monument along Bridge
Creek, a tributary to the John Day...
Urban ecosystems are characterized by human disturbance and changes in the amount, types, and spatial arrangement of wildlife habitat. The relative importance of habitat and human associated variables to urban birds is unknown. In 1999, I surveyed spring bird and plant communities along 54 perennial streams
in the Portland, Oregon...
Two studies on Catherine Creek and Meadow Creek of the Upper Grande Ronde
River basin, quantified several physical and biotic influences on woody riparian community
composition and structure. The Catherine Creek study examined the association of woody
riparian species with elevational and geomorphic gradients. The Meadow Creek study
examined the...
Because riparian canopy controls most energy inputs to stream
ecosystems, it directly affects the structure of aquatic food webs and the
ecological processes that govern interactions among trophic levels. This
study addresses the interdependence among riparian canopy, benthic
community structure, and the carrying capacity of high desert streams for
salmonid...
Recognizing the importance of native black cottonwood-dominated riparian
forests is especially important to preserve, protect, and manage for biodiversity in
the Willamette River Valley. Species composition, structure, and biomass along a
successional gradient from stand initiation to late succession of black cottonwood
(Populus balsamfera L. subsp. trichocarpa (T. & G.)...
Denitrification, the biological or chemical reduction of ionic nitrogen oxide or dinitrogen, has not been widely studied in forest ecosystems despite widespread interest in other facets of the forest nitrogen economy. This study had three main objectives: to determine whether potential for denitrification exists in forest riparian and hill slope...
Elk River is a sixth order stream, draining a 200 square
kilometer basin in the Klainath Mountain province of
southwestern Oregon. Timber harvesting began in the basin
during the 1950's, with peak removal of wood occurring in the
mid to late 1960's. This activity lead to an increase in the...
The eruption of Mt. St. Helens provided the
opportunity to study secondary production of grazing insects in the context of disturbance. Two stream sites were chosen that significantly differed in how their
watersheds were impacted by the eruption. Clearwater Creek was catastrophically disturbed (physical alteration of habitat, loss of riparian...
As a developer in the Pacific Northwest, you have a unique opportunity to help maintain and improve the health of streams and riparian areas. This brochure describes what a riparian area is, why it is important, and what you can do to take care of the land. A healthy riparian...
A s a recreationist, you have a unique opportunity to help maintain or improve the health of streams and riparian areas. A riparian area is the land adjacent to a stream, lake, or wetland. Healthy riparian areas often have moist, fertile soils that support many types of plants. These plants...