Contributions Of Riparian Vegetation And Stream Morphology To Headwater Stream Temperature Patterns In The Oregon Coast Range

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Contributions of Riparian Vegetation and Stream Morphology to Headwater Stream Temperature Patterns in the Oregon Coast Range

Author : Danielle D. Smith
Publisher :
ISBN 13 :
Total Pages : 338 pages
Book Rating : 4.:/5 (65 download)

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Book Synopsis Contributions of Riparian Vegetation and Stream Morphology to Headwater Stream Temperature Patterns in the Oregon Coast Range by : Danielle D. Smith

Download or read book Contributions of Riparian Vegetation and Stream Morphology to Headwater Stream Temperature Patterns in the Oregon Coast Range written by Danielle D. Smith and published by . This book was released on 2004 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: The role of riparian forests in maintaining temperatures of headwater streams is well established and is a foundation of forest practice rules designed to protect streamwater quality. However, detailed investigation is still needed quantifying specific characteristics of stream systems that affect streamwater temperature including riparian features, stream morphology, and subsurface interactions. The objectives of this research were to investigate summertime streamwater temperature patterns and identify characteristics within headwater streams and riparian zones that influence stream temperature. This study was designed to evaluate these relationships prior to logging in 38 perennial headwater catchments of the Oregon Coast Range. Stream reaches of greater than 1000 m were instrumented with temperature probes and selected stream and riparian characteristics were measured at 60-m intervals within each study reach in 2002 and 2003. A subset of the streams was examined in 2003 to determine the potential influence of streamwater residence time on temperature patterns. Findings suggest that canopy cover is the driving factor controlling summer stream temperature in these small headwater streams, but other stream and riparian characteristics should not be discarded. Longitudinal stream temperature patterns were quite variable for these forested streams and results suggest a high degree of complexity in small headwater streams. Maximum 7-day moving average temperatures ranged from 11.4°C to 16.8°C, with three streams above the standard 16°C threshold. Effects of stream and riparian characteristics on stream temperature were strongest when average of the weekly high temperature was assessed, suggesting this may be a more sensitive index of stream temperature than the commonly used maximum 7-day moving average. Results of tracer dilution tests were inconclusive in that temperature was not consistently correlated to residence time in streams.

The Land-water Interface

Author : Mayumi Takahashi
Publisher :
ISBN 13 :
Total Pages : 170 pages
Book Rating : 4.:/5 (568 download)

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Book Synopsis The Land-water Interface by : Mayumi Takahashi

Download or read book The Land-water Interface written by Mayumi Takahashi and published by . This book was released on 2003 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 how the composition and structure of the riparian forest changed with distance from the stream, and 3) extract major underlying environmental gradients explaining riparian forest community from riparian vegetation data. A 30 m x 30 m sample site was randomly located on each side of upper Camp Creek in each of 19 reaches, and within each site three consecutive 30 m x 10 m belt-transects established perpendicular to the stream flow. Overstory and understory vegetation was sampled in each belt transect. Environmental variables sampled included slope, aspect, height above summer low flow, elevation above sea level. Non-metric Multidimensional Scaling and Indicator Species Analysis was used to describe characteristics of riparian plant communities. Distinct riparian vegetation patterns were observed in upper Camp Creek with increasing distance from stream. Both overstory and understory vegetation quickly changed with increasing distance from stream. Areas within ten meters from stream were characterized as mesic riparian environments while areas twenty meters away from stream were characterized as upland conifer forest environments. Vegetation composition was ordered along an inferred moisture gradient from streamside to hillslope, and distance from stream and height above summer low flow were almost equally correlated to the gradient. Tall shrubs including salmonberry, sword fern and vine maple are important component of riparian vegetation. Channel-reach morphology little differentiated riparian vegetation. A few species were significantly abundant in a specific reach of channel morphology. However, results of this study about relationships between channel-reach morphology and riparian vegetation were inconclusive.

Riparian Areas

Author : National Research Council
Publisher : National Academies Press
ISBN 13 : 0309082951
Total Pages : 449 pages
Book Rating : 4.3/5 (9 download)

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Book Synopsis Riparian Areas by : National Research Council

Download or read book Riparian Areas written by National Research Council and published by National Academies Press. This book was released on 2002-10-10 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Clean Water Act (CWA) requires that wetlands be protected from degradation because of their important ecological functions including maintenance of high water quality and provision of fish and wildlife habitat. However, this protection generally does not encompass riparian areasâ€"the lands bordering rivers and lakesâ€"even though they often provide the same functions as wetlands. Growing recognition of the similarities in wetland and riparian area functioning and the differences in their legal protection led the NRC in 1999 to undertake a study of riparian areas, which has culminated in Riparian Areas: Functioning and Strategies for Management. The report is intended to heighten awareness of riparian areas commensurate with their ecological and societal values. The primary conclusion is that, because riparian areas perform a disproportionate number of biological and physical functions on a unit area basis, restoration of riparian functions along America's waterbodies should be a national goal.

Stream Temperatures, Riparian Vegetation, and Channel Morphology in the Upper Grande Ronde River Watershed, Oregon

Author : Todd S. Bohle
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (36 download)

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Book Synopsis Stream Temperatures, Riparian Vegetation, and Channel Morphology in the Upper Grande Ronde River Watershed, Oregon by : Todd S. Bohle

Download or read book Stream Temperatures, Riparian Vegetation, and Channel Morphology in the Upper Grande Ronde River Watershed, Oregon written by Todd S. Bohle and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Upper Grande Ronde River Watershed in northeastern Oregon is considered important habitat for threatened stocks of chinook salmon (Oncorhynchus tshawytscha). Documented reductions in channel complexity and riparian vegetation within the watershed have increased concern over loss of viable habitat. An important component of salmonid habitat is stream temperature during critical summer periods. In general, annual maximum stream temperatures and diurnal fluctuations in the Upper Grande Ronde River were found to reflect local reach characteristics, position in the drainage, and large-scale changes in valley shape. Stream temperatures on the Grande Ronde River at a distance of 71 km from the watershed divide exceeded 14°C, the "upper preferred temperature" for chinook salmon, more than 90% of time in July of 1991 and in July and August of 1992. While the occurrence of temperatures above 14°C were less common in the headwaters of the Grande Ronde River, downstream of a large meadow (i.e., Vey Meadow) (29 km from the divide) 14°C was exceeded at least 60% of the time during the same three month period. Seven-day maximum stream temperatures on the Upper Grande Ronde River ranged between 17.9°C and 26.6°C in 1991 and between 19.1°C and 26.7°C in 1992. Diel fluctuations on the mainstem were greatest immediately below Vey Meadow (about 12°C) but tended to stabilize at approximately 8°C at distances of over 49 km from the divide. Maximum stream temperatures in tributaries of the Upper Grande Ronde River varied by as much as 11°C (during 1992), reflecting large differences in stream cover, aspect, and flow. The timing of annual maximums seemed to be strongly linked to aspect during 1992. In addition, the high-elevation, forested tributaries had annual maximum stream temperatures and diel fluctuations which were 3°C lower than those associated with more open, low-elevation sites. Relationships between stream temperatures, riparian vegetation, and channel morphology characteristics were evaluated for 11 tributary reaches. Differences in stream cover, average flow velocity, bankfull depth and percent undercut bank were found to be significantly (p

Examining Effectiveness of Oregon's Forest Practice Rules for Maintaining Warm-season Maximum Stream Temperature Patterns in the Oregon Coast Range

Download Examining Effectiveness of Oregon's Forest Practice Rules for Maintaining Warm-season Maximum Stream Temperature Patterns in the Oregon Coast Range PDF Online Free

Author : Jennifer Marie Fleuret
Publisher :
ISBN 13 :
Total Pages : 260 pages
Book Rating : 4.:/5 (72 download)

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Book Synopsis Examining Effectiveness of Oregon's Forest Practice Rules for Maintaining Warm-season Maximum Stream Temperature Patterns in the Oregon Coast Range by : Jennifer Marie Fleuret

Download or read book Examining Effectiveness of Oregon's Forest Practice Rules for Maintaining Warm-season Maximum Stream Temperature Patterns in the Oregon Coast Range written by Jennifer Marie Fleuret and published by . This book was released on 2006 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stream temperature, as an important component of stream ecosystems, can be affected by forest harvesting through removal of riparian shade and changes in hydrology. Riparian Management Areas (RMAs), as implemented through the current Oregon Forest Practice Rules, are designed, in part, to maintain stream temperature following forest harvesting. However, effectiveness of RMAs in achieving this outcome is uncertain. The objective of this research was to examine effectiveness of RMAs, as outlined by the current Oregon Forest Practices Act and the Northwest State Forests Management Plan, in maintaining warm-season temperature patterns of streamwater. Twenty-two headwater streams, on either private- or state-owned forestlands in the Oregon Coast Range that encompassed a range of RMA widths and harvest prescriptions, were evaluated for effectiveness of RMAs on stream temperature. A Before-After-Control-Impact/Intervention design was used, and each stream had an upstream control and a downstream treatment reach. Temperature probes were placed 1) at the top of the control reach, 2) at the boundary between the control and treatment reaches, and 3) at the bottom of the treatment reach from June to September for four years starting in 2002. All but one stream have at least two years of pre2 harvest temperature data, and one year of post-harvest temperature data. Selected stream and riparian characteristics were collected every 60 m within the control and treatment reaches once prior to and once following harvest. I hypothesized that RMAs would be effective if pre-harvest warmseason maximum temperature patterns were maintained following harvest treatments. Comparisons of temperature patterns between control and treatment reaches both pre- and post-harvest indicate that my hypothesis should be rejected because warm-season maximum temperature patterns were not maintained when mean values in treatment reaches across all study streams were considered. Difference in temperature gradients between control and treatment reaches averaged 0.6°C, based on two years of pre-harvest and one year of post-harvest data. This indicates that more warming or less cooling occurred in treatment reaches than occurred in control reaches when pre-harvest and post-harvest periods were compared, suggesting that current RMAs for small- and medium fishbearing streams of the Oregon Coast Range are not effective for maintenance of warm-season maximum temperature patterns.

Influence of Stream Characteristics and Grazing Intensity on Stream Temperatures in Eastern Oregon

Author :
Publisher :
ISBN 13 :
Total Pages : 28 pages
Book Rating : 4.:/5 (319 download)

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Book Synopsis Influence of Stream Characteristics and Grazing Intensity on Stream Temperatures in Eastern Oregon by :

Download or read book Influence of Stream Characteristics and Grazing Intensity on Stream Temperatures in Eastern Oregon written by and published by . This book was released on 1999 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Riparian Vegetation Composition and Structure Associated with Channel Morphology of Headwater Meadow Streams in the Blue Mountains, Northeast Oregon

Download Riparian Vegetation Composition and Structure Associated with Channel Morphology of Headwater Meadow Streams in the Blue Mountains, Northeast Oregon PDF Online Free

Author : Zachary O. Toledo
Publisher :
ISBN 13 :
Total Pages : 188 pages
Book Rating : 4.:/5 (568 download)

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Book Synopsis Riparian Vegetation Composition and Structure Associated with Channel Morphology of Headwater Meadow Streams in the Blue Mountains, Northeast Oregon by : Zachary O. Toledo

Download or read book Riparian Vegetation Composition and Structure Associated with Channel Morphology of Headwater Meadow Streams in the Blue Mountains, Northeast Oregon written by Zachary O. Toledo and published by . This book was released on 2003 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Selected Water Resources Abstracts

Author :
Publisher :
ISBN 13 :
Total Pages : 772 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis Selected Water Resources Abstracts by :

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1990 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:

The Influence of Contemporary Forest Harvesting on Summer Stream Temperatures in Headwater Streams of Hinkle Creek, Oregon

Author : Kelly Maren Kibler
Publisher :
ISBN 13 :
Total Pages : 196 pages
Book Rating : 4.:/5 (163 download)

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Book Synopsis The Influence of Contemporary Forest Harvesting on Summer Stream Temperatures in Headwater Streams of Hinkle Creek, Oregon by : Kelly Maren Kibler

Download or read book The Influence of Contemporary Forest Harvesting on Summer Stream Temperatures in Headwater Streams of Hinkle Creek, Oregon written by Kelly Maren Kibler and published by . This book was released on 2008 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stream temperature is a water quality parameter that directly influences the quality of aquatic habitat, particularly for cold-water species such as Pacific salmonids. Forest harvesting adjacent to a stream can increase the amount of solar radiation the stream receives, which can elevate stream temperatures and impair aquatic habitat. Oregon Forest Practice Rules mandate that forest operators leave Riparian Management Areas (RMAs) adjacent to streams in order to minimize the water quality impacts from forest harvesting. However, RMAs that contain overstory merchantable conifers are not required for small non-fish-bearing streams in Oregon, thus there is potential for increases in stream temperature to occur in headwater streams after harvesting. There is concern that increases in stream temperatures and changes to onsite processes in non-fish-bearing, headwater streams may propagate downstream and impair habitat in fish-bearing streams. The objectives of the following work are to assess the effects of contemporary forest management practices on stream temperatures of small non-fish-bearing headwater streams and to develop new knowledge regarding the physical processes that control reach-level stream temperature patterns. Summer stream temperatures were measured for five years in six headwater streams in the Hinkle Creek basin in southern Oregon. After four years, four of the streams were harvested and vegetated RMAs were not left between the streams and harvest units. The watersheds of the two remaining streams were not disturbed. Post-harvest stream temperatures were monitored for one year in all six streams. Each harvested stream was paired with one unharvested stream and regression relationships for maximum, minimum and mean daily stream temperatures were developed. Changes to temperatures of harvested streams were detected by comparing the mean pre-harvest regression relationship to the mean post-harvest relationship. Change detection analyses that considered the mean response among all four harvested streams indicated that maximum daily stream temperatures did not increase after harvesting, but that minimum and mean daily temperatures decreased significantly after harvesting. Additionally, diel stream temperature fluctuations were significantly greater one year after harvesting. Pre- and post-harvest surveys of canopy closure in the harvested and unharvested streams were completed in order to compare levels of stream shading before and after harvest. The post-harvest survey quantified canopy closure from remaining overstory vegetation as well as from logging slash that partially covered the harvested streams. The surveys indicated that mean overstory canopy closure in the harvested streams decreased by 84% as a result of the harvest, but as the logging slash provided considerable cover, total canopy closure decreased by only 20%. It is possible that the logging slash effectively attenuated solar radiation and prevented extreme temperature increases in the harvested streams. However, it is likely that streamflow increased after harvesting and that the increased streamflow also prevented increases to maximum temperatures and contributed to lower minimum and mean stream temperatures.

Managing Oregon's Riparian Zone for Timber, Fish and Wildlife

Author :
Publisher :
ISBN 13 :
Total Pages : 108 pages
Book Rating : 4.:/5 (319 download)

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Book Synopsis Managing Oregon's Riparian Zone for Timber, Fish and Wildlife by :

Download or read book Managing Oregon's Riparian Zone for Timber, Fish and Wildlife written by and published by . This book was released on 1987 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Key Controls of Stream Temperature in Rock Creek, Oregon

Author : Cleopatra Sanda Neculae
Publisher :
ISBN 13 :
Total Pages : 47 pages
Book Rating : 4.:/5 (761 download)

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Book Synopsis Key Controls of Stream Temperature in Rock Creek, Oregon by : Cleopatra Sanda Neculae

Download or read book Key Controls of Stream Temperature in Rock Creek, Oregon written by Cleopatra Sanda Neculae and published by . This book was released on 2011 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study documents the main controls of summer stream temperatures in a watershed identified as impaired due to high thermal loads. The most important controls examined are riparian vegetation height and canopy density, discharge, channel morphology, and surface inflows. The study uses data acquired from field measurements to evaluate stream temperature, channel morphology, and discharge, from LiDAR imaging data to describe riparian vegetation characteristics, and from a 10-m DEM to estimate surface inflows. These data are also inputs to Heat Source, a deterministic model that estimates changes in stream temperature for a segment of the stream by creating a thermal profile under existing conditions. The study uses a series of scenarios to assess the impact of the four identified factors and its implications for riparian restoration. The study results indicate that while riparian restoration is an important mechanism of lowering stream temperatures, it is insufficient to reach standards identified as conducive to viable salmon habitats. To attain this goal, the restoration of riparian vegetation must be paired with other approaches that lower the temperature of the incoming surface flows significantly.

Policy Patterns Across Riverscapes

Author : Brett A. Boisjolie
Publisher :
ISBN 13 :
Total Pages : 120 pages
Book Rating : 4.:/5 (952 download)

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Book Synopsis Policy Patterns Across Riverscapes by : Brett A. Boisjolie

Download or read book Policy Patterns Across Riverscapes written by Brett A. Boisjolie and published by . This book was released on 2016 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Land management policies are ideas about nature projected onto the landscape. Culminations of social, economic, and scientific influences, these policies create standards affecting the function of ecological systems. In the case of riparian lands in the Oregon Coast Range, policy requirements vary considerably across federal, state, and private land ownerships. Protective measures, such as the adoption of fixed buffer widths for maintaining vegetation, are intended to preserve natural processes important to instream habitat and water quality. However, the "policy landscape" of variable management standards can result in a fragmented approach to policy protection. This fragmentation complicates recovery efforts for threatened anadromous fish species such as coho salmon (Oncorhynchus kisutch), which require connectivity in suitable habitat segments throughout the river network. Taking a riverscape perspective, this study evaluates how aquatic protections vary across the river and its valley. To explore the patterns created from variable standard, the study first delineates categories of riparian management standards in the Oregon Coast Range. Using a geographic information system (GIS), these standards are mapped across the river networks of this region. The extent of each policy category is quantified in stream kilometers in order to evaluate policy efforts within and across the riverscapes of the Oregon Coast Range. A model of intrinsic potential for coho salmon habitat is used to identify the policy standards in stream reaches where flow, valley constraint, and channel gradient are appropriate for coho salmon habitat. A second model of the stream network (hydrography) is developed to evaluate how differences in stream delineation can influence policy patterns. Results indicate that riparian lands of the Oregon Coast Range are protected by variable standards for land management, including buffer widths that range from 0 to ~152m. In streams important to coho salmon, a lower proportion of the stream network was found to be protected by policy standards compared to the watershed and ESU scale. A lack of stream data central to policy application (fish use, stream flow duration, mean annual flow, water use) complicated our ability to attribute stream segments with specific land management requirements. The choice of hydrographic data was also found to influence the proportional extent of policies within riverscapes. This framework for assessing the spatial distribution of policies can provide insights for future studies of riverscape systems.

Geomorphic Influences on Habitat Formation, Distribution, and Development and the Classification of Upland Coastal Oregon Streams

Author : Michael D. Hurley
Publisher :
ISBN 13 :
Total Pages : 116 pages
Book Rating : 4.:/5 (259 download)

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Book Synopsis Geomorphic Influences on Habitat Formation, Distribution, and Development and the Classification of Upland Coastal Oregon Streams by : Michael D. Hurley

Download or read book Geomorphic Influences on Habitat Formation, Distribution, and Development and the Classification of Upland Coastal Oregon Streams written by Michael D. Hurley and published by . This book was released on 1989 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: A framework is presented for a more causal explanation and ordering of stream characteristics than traditional means have used. Patterns of stream habitat distribution are related to particular characteristics of the geomorphology of watersheds. Variability in stream characteristics can be explained by the spatial distribution of properties of the watershed and by identifying stages in the development of stream habitat. This has implications for the classification of streams in a geomorphic context, emphasizing the concepts of capacity and genesis. Within the context of a hierarchical watershed classification, stream segment is considered the most useful classification level for understanding habitat distribution and dynamics. Basins in basalt and sandstone geologic formations in the Oregon Coast Range were investigated for stream habitat distribution. In streams flowing through sandstone, repetitive patterns of large-scale valley segments are identified in headwaters to large rivers. Segment boundaries are identified by changes in valley morphology. Alternating patterns of wide valleys and constricted valleys are common in some landtype associations. The formation of these segments is influenced by bedrock stratigraphy and large-scale geomorphic processes such as slump-slides. Valley dimensions are quantified by nondimensional indices of valley width / channel width and the stream gradient index. Pool distribution was intensively analysed in 2.8 kilometers of a fourth order stream that flows through basalt bedrock. The mainstem was stratified by tributary junctions, each of which was further divided into 3 equal zones. Distributional patterns were analyzed by pool spacing, linear nearest neighbor, and by composition of zones. Pool spacing does not conform to the expected normal distribution with a median spacing at 5-7 channel widths. Pool spacing is strongly skewed towards shorter spacings and has a median spacing at 2-3 channel widths. Pools of similar size and type occur locally, which indicates that different areas of the stream have different conditions for habitat formation and development. Habitat distribution and composition is related to valley morphology, hillslope processes, location in relation to tributary junctions, and time since disturbance. Debris torrents are the dominant processes influencing the stream, these supplying sediment and instream structure of wood and boulders, as well as influencing channel slope. A balance between disturbance and recovery exists in unmanaged as well as perturbed watersheds. Effective management of watersheds must maintain the geomorphic integrity of the valley and stream. Classification of the stream and habitat in a geomorphic context enhances explanation and the understanding of the interaction between watershed form and process and characteristics of the stream. Stream habitat formation, distribution, and dynamics are better understood in the context of geomorphic concepts such as sediment storage and dynamics.

Estimating Water Temperatures in Small Streams in Western Oregon Using Neural Network Models

Author : John C. Risley
Publisher :
ISBN 13 :
Total Pages : 72 pages
Book Rating : 4.3/5 (121 download)

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Book Synopsis Estimating Water Temperatures in Small Streams in Western Oregon Using Neural Network Models by : John C. Risley

Download or read book Estimating Water Temperatures in Small Streams in Western Oregon Using Neural Network Models written by John C. Risley and published by . This book was released on 2003 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Subsurface Flow of a Forested Riparian Area in the Oregon Coast Range

Author : Maryanne Reiter
Publisher :
ISBN 13 :
Total Pages : 216 pages
Book Rating : 4.:/5 (283 download)

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Book Synopsis Subsurface Flow of a Forested Riparian Area in the Oregon Coast Range by : Maryanne Reiter

Download or read book Subsurface Flow of a Forested Riparian Area in the Oregon Coast Range written by Maryanne Reiter and published by . This book was released on 1990 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was undertaken to gain further understanding of the subsurface hydrology for a stream-adjacent riparian area in Western Oregon's Coast Range. Spatial and temporal fluctuations of the free water surface of a toeslope, adjacent riparian area, and stream channel in a forested terrace reach were monitored over a period of one year. A total of 27 piezometers were installed (nine in each of three transects established perpendicular to the stream) in a stream-adjacent terrace and hillslope. These piezometers were monitored from September 26, 1989 to July 25, 1990. Results indicate that the direction of flow within a forested terrace can vary throughout the year. During the drier months of September and October, flow direction was generally towards the stream. However, by November the direction of flow for those areas closest to the stream had begun to change. In some cases the direction of flow changed up to 180° from the September direction. The location of influent/effluent zones along the stream (i.e., zones along the stream where the terrace has a lower or higher hydraulic head than the stream, respectively) also varied throughout the year. During October, 1989 the furthest upvalley stream-adjacent piezometer had hydraulic heads greater than the stream for the entire month, while two other stream adjacent piezometers did not. During normal precipitation in January, 1990 both furthest upvalley and the middle stream-adjacent piezometers had hydraulic heads greater than the stream for the entire month. By July, 1990 only the middle stream-adjacent piezometer had a hydraulic head greater than the stream for the entire month, while the furthest upvalley piezometer had a higher head for 33% of the month and the hydraulic head of furthest downvalley piezometer never exceeded that of the stream. For the Deer Creek study site, subsurface velocities were estimated to be in the range of 10-8 to 10-11 m/s resulting in a 3.8 year minimum travel time for storm water to reach the stream. Thus, soil matrix velocities using the Darcy equation were not sufficient to generate stormflow. However, no overland flow was observed during storm events, indicating that alternative subsurface flow pathways, such as macrochannels, are being utilized. Previous research has suggested that the release of water from terrace storage in small headwater streams is no.t sufficient to maintain baseflow. The results of the Deer Creek study support this conclusion. Furthermore, the results of this study indicate that forested riparian areas are hydrologically complex with respect to both space and time and that oversimplification of these systems may lead to misinterpretation of other processes associated with subsurface water dynamics.

Riparian Litter Inputs to Streams in the Central Oregon Coast Range

Author : Stephanie K. Hart
Publisher :
ISBN 13 :
Total Pages : 204 pages
Book Rating : 4.:/5 (646 download)

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Book Synopsis Riparian Litter Inputs to Streams in the Central Oregon Coast Range by : Stephanie K. Hart

Download or read book Riparian Litter Inputs to Streams in the Central Oregon Coast Range written by Stephanie K. Hart and published by . This book was released on 2006 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 order streams affect the processes and condition of adjacent and downstream reaches based on the amount of particulate organic matter that is intercepted, retained, or exported. The central Oregon Coast Range provides an ideal opportunity to study how deciduous dominated and coniferous dominated riparian forests influence small streams within a matrix of managed riparian forests. In coastal Oregon riparian forests, we investigated lateral and vertical litter inputs to sixteen streams throughout a year and assessed how these inputs were influenced by density of deciduous dominated (mainly red alder (Alnus rubra)) or coniferous dominated (mainly Douglas-fir (Pseudotsuga menziesii)) overstory, understory, and lateral slope. Deciduous site vertical litter inputs (504 g m-2 yr-1 (95% CI: 447-562)) were estimated to exceed those from coniferous sites (394 g m-2 yr-1 (336-452)) by 110 g m-2 (29-192) over the full year. Annual lateral inputs (per meter of stream bank on one side) at deciduous sites (109 g m-1 yr-1 (76-143)) were estimated to be 47 g m-1 (1-95) more than coniferous sites (63 g m-1 yr-1 (29-97)). Annual inputs at coniferous sites were dominated by deciduous leaves, coniferous needles, and twig litter types. Deciduous leaves, deciduous-other, and small unidentifiable litter types dominated the annual inputs at deciduous sites. When evaluated temporally, November was the most pivotal month differentiating coniferous and deciduous site litter inputs. At deciduous sites, lateral litter movement increased with slope, but we did not see the same relationship for coniferous sites except in spring/summer months. Lateral inputs were quantitatively greatest in autumn months for both overstories, but were proportionately greater in winter. Regardless of slope, there was no indication that understory plants were obstructing annual lateral litter inputs or that annual lateral litter inputs were moving more than 5 m down slope. The percent nitrogen of annual total vertical litter was estimated to be 1.9% N (1.5-2.4) at deciduous sites and 1.2% N (0.8-1.7) at coniferous sites. Average % nitrogen of individual litter types were either greater in deciduous sites or not different among overstories, indicating that one can generally expect coniferous sites to have lower % N litter inputs overall. The annual nitrogen flux entering each meter-length (from above and both sides) of standard 4 m-wide streams at a deciduous sites (42 g N m-1 of stream) was twice that of coniferous sites (21 g N m-1 of stream). Annual total litter carbon flux into each meter-length of 4 m-wide streams was estimated to be 1154 g C m-1 of stream at deciduous sites and 880 g C m-1 of stream at coniferous sites. On average, autumn months (October-December) accounted for 46-59% of annual vertical C flux and 56-70% of annual vertical N flux at coniferous and deciduous sites. Our results suggest that red alder dominated riparian zones of the central Oregon Coast Range have significantly different quantity, timing, and quality of leaf litter inputs to streams than conifer dominated forests. Varied topography adjacent to streams with red alder dominated overstory has greater impact on the quantity, quality, and timing of total inputs than at coniferous sites. The cumulative effects from many small red alder dominated streams exporting to downstream reaches include more pronounced seasonality of litter delivery, with greater carbon and nitrogen loading annually, than expected from conifer dominated streams. Differences in overstory and topography in Oregon Coast Range riparian forests directly impact the delivery of nutrients and can affect the structure and composition of food webs in these ecosystems.

The Influence of Environmental and Physical Factors on the Thermal Patterns of Headwater Streams

Author : Craig A. Carr
Publisher :
ISBN 13 :
Total Pages : 310 pages
Book Rating : 4.:/5 (564 download)

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Book Synopsis The Influence of Environmental and Physical Factors on the Thermal Patterns of Headwater Streams by : Craig A. Carr

Download or read book The Influence of Environmental and Physical Factors on the Thermal Patterns of Headwater Streams written by Craig A. Carr and published by . This book was released on 2003 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: A case study was performed in 2000 and 2001 to characterize the thermal pattern of four morphologically similar eastern Oregon streams and to identify the physical and environmental factors that expressed significant and functionally viable relationships with stream temperature (daily maximum, daily minimum and daily rate of heating). Stream and environmental attributes were measured at various locations along each stream to provide a data set comprised of variables representing daily stream temperatures (minimum, maximum and rates of heating), daily air temperatures (minimum and maximum), shade, elevation, elevation change and length. Data from the 20 hottest days were analyzed using analysis of variance and regression-based path analysis. With the exception of those reaches that were influenced by groundwater or subsurface flow, downstream reaches consistently experienced increases in the daily maximum stream temperature. The most significant parameter with respect to daily maximum stream temperature appeared to be reach elevation; expressed through reach location in the watershed. Maximum air temperature also positively influenced maximum stream temperature however, only on streams that expressed significant variation in maximum air temperature. The dominant influence of groundwater on maximum stream temperature was also apparent. Significant reach level variation in daily minimum stream temperatures was not observed in this study, however most streams did record increases in the downstream direction. Daily minimum air temperature was consistent across all streams in expressing the most significant relationship with daily minimum stream temperature. With the exception of groundwater influenced reaches, all streams exhibited obvious downstream increases in the daily rate of stream heating. Daily minimum air temperature consistently exhibited a significant negative association with the rate of heating and a relationship was also implied between reach elevation, maximum stream temperature and minimum stream temperature and this stream temperature response. Groundwater and subsurface flow, when present, also appeared to influence the daily rate of stream heating. Resource management activities should have little impact on the parameters found, on these streams, to be associated with stream temperature. Location in the watershed and climatic influence through both minimum and maximum air temperatures emerged as the dominant factors with respect to stream thermal patterns.