Download or read book The Importance of Wood in Headwater Streams of the Oregon Coast Range written by Christine May and published by . This book was released on 2004 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Importance of Wood in Headwater Streams of the Oregon Coast Range written by Christine May and published by . This book was released on 2004 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spatial and Temporal Dynamics of Sediment and Wood in Headwater Streams in the Central Oregon Coast Range written by Christine L. May and published by . This book was released on 2001 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Channels that were scoured to bedrock by debris flows provided unique opportunities to calculate the rate of sediment and wood accumulation, to make inferences about processes associated with input and transport of sediment, and to gain insight into the temporal succession of channel morphology following disturbance. In an intensive investigation of 13 channels the time since the previous debris flow was estimated using dendrochronology. The volume of wood in the channel was positively and linearly correlated with the time since the previous debris flow. The pattern of sediment accumulation was non-linear and appeared to increase as the storage capacity of the channel increased through time. Wood stored the majority of the sediment in these steep headwater streams, and landslides and wind throw were the dominant mechanisms for delivering wood to the channel. With an adequate supply of wood, small streams have the potential to store large volumes of sediment in the interval between debris flows and can function as one of the dominant storage reservoirs for sediment in mountainous terrain. In an extensive investigation of 125 headwater streams, the spatial and temporal patterns of debris flow occurrence and deposition were investigated. The temporal distribution of debris flow occurrence varied with network structure and drainage area of the tributary basin. Network structure may affect the frequency of debris flows delivered to the mainstem river valley because it reflects the number of potential landslide source areas and the routing ability of the channel. Tributary basins with larger drainage areas and more convergent topography had a greater proportion of channels in the younger, post-debris flow age-classes compared to smaller basins with less convergent topography. The flux rate of material delivered to the confluence with the larger river also influenced the development of debris flow fans. Fans at the mouth of tributary basins with smaller drainage areas had a higher likelihood of being eroded in the interval between debris flows, while larger, more persistent fans were present at the mouth of bigger basins. Valley floor width of the mainstem river typically constrained fan development and was also an important predictor of fan size.

Download or read book A Guide to Placing Large Wood in Streams written by and published by . This book was released on 1995 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

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.

Download or read book The Effect of the Size and Orientation of Large Wood on Pool Volume in Two Oregon Coast Range Streams written by Pamela Lombard and published by . This book was released on 1997 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was conducted to determine how the size and orientation of large wood placed in streams in combination with peak flows, substrate and channel gradient affect pool volume, surface area and maximum depth in two coastal Oregon streams. Eighteen Douglas-fir (Pseudotsuga menziesii) logs were placed in each of two streams, J-Line Creek and Preacher Creek, in the summer of 1989. Surveys were conducted annually from 1989-1996 at summer low flow using a total station electronic theodolite. The orientation of the introduced wood and the parameters of residual pools associated with the wood were determined from high resolution topographic maps made from the surveys. Residual pool volume associated with the introduced wood increased 2,500 percent over the seven years for J-Line Creek and 30 percent for Preacher Creek. Large spanners, logs placed perpendicular to the stream flow and flush with the stream bottom, had the greatest pool volume associated with them, however horizontal orientations shifted downstream over time. Large ramps, logs placed at a downstream orientation and angled up onto the bank, were the most stable treatment. Differences between the two watersheds and an interaction variable between the diameter of the introduced wood and the horizontal orientation of the introduced wood were the significant variables which entered the multiple linear regression model for residual pool volume. These variables, as well as the vertical orientation of the introduced wood, were significantly correlated to both residual pool surface area and maximum depth. The recurrence interval of the annual maximum instantaneous peak flow was not significantly associated with residual pool volume, surface area nor maximum depth. Multiple regression models explained, at most, twenty-eight percent of the variability in residual pool volume, maximum depth and surface area. Estimates of pool volume obtained with aquatic habitat inventories (Bisson et al., 1982) were compared with residual pool calculations determined from the topographic maps. Pool volume in a reach determined by aquatic habitat inventories explained 96 percent of the variability of residual pool volume in a reach, however estimates of individual pool volume explained only 40 percent of the variability in residual pool volume.

Download or read book The Geomorphic Significance of Log Steps in Forest Streams of the Oregon Coast Range written by Richard Alan Marston and published by . This book was released on 1980 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Examination of Several Methods of Quantifying Forest Structure in Headwater Riparian Forests of Western Oregon written by Zane A. Haxton and published by . This book was released on 2011 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Headwater streams are generally small, first-order streams that can comprise up to 80% (by stream length) of the drainage network in mountainous areas of the Pacific Northwest. These streams are intimately connected with downstream reaches, serving as a source of sediment, woody debris, organic matter and nutrients. The surrounding forests can strongly influence the ecology of headwater streams by regulating microclimate, influencing nutrient and organic matter cycling process, and providing habitat for wildlife species. Central to the provision of ecosystem services by these headwater forests is their structure, the three-dimensional arrangement of trees, shrubs, snags and down wood in space. This thesis explored several methods of quantifying forest structure in headwater riparian forests of western Oregon. N-tree distance sampling, a sampling method where the nearest n trees to a sample point are measured, was compared with fixed plot and variable plot sampling for estimation of density and basal area in a simulation study using stem-mapped data taken from 8 headwater sites across western Oregon. In general, variable plot sampling gave the best statistical performance for estimation of basal area, while fixed plot sampling gave the best statistical performance for estimation of density. While n- tree distance sampling gave reasonable performance on some stem maps, the sampling method performed poorly for estimating density of populations with a clumped spatial pattern. Relative root mean square error of the best n-tree distance sampling estimator was up to 75% higher than for fixed plot sampling under these conditions. Neighborhood-based indices are a set of diversity measures that are based on the relationship between a reference tree and a certain number of nearest neighbors (i.e. trees to which it has the lowest horizontal distance). I compared the bias and relative root mean square error of several different methods of choosing reference trees for neighborhood-based index calculation, using stem-mapped data from the same 8 headwater sites. The selection of a random tree from a fixed plot gave the lowest absolute relative bias, but results with this method were quite variable, with relative root mean square error ranging from 33-67% for the species mingling index and 21-25% for the diameter differentiation index. The nearest-tree (selection of the nearest tree to the sample point) and azimuth (selection of the first tree from north in a fixed plot) methods were biased, but had lower variability, with relative root mean square error ranging from 31-64% for the species mingling index and 18-22% for the diameter differentiation index. The variable plot method gave highly variable results for all species combined, but performed well for some individual species. I close with an exploration of the use of measures of forest structure in characterizing the Trask Watershed, located in the headwaters of the northern Oregon Coast Range. The structure of the Trask Watershed is essentially even-aged, having regenerated in the aftermath of the Tillamook Burn. Douglas-fir and red alder are the most prevalent species, with western hemlock, western redcedar and noble fir locally abundant. While neighborhood-based indices were somewhat informative, they offered an impoverished picture of structural diversity in the Trask Watershed by ignoring the contribution made by tall shrubs such as vine maple and western hazelnut.

Download or read book Forests and Streams of the Oregon Coast Range written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forest and Stream Management in the Oregon Coast Range written by Stephen D. Hobbs and published by . This book was released on 2002 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This major volume presents a wealth of fundamental and applied research on managing Coast Range forest and stream ecosystems. Written primarily for managers and resource specialists, the book will also appeal to policymakers, resource scientists, forest landowners, the conservation community, and students interested in forestry, fisheries, and wildlife sciences.

Download or read book Undercut Streambanks in Forested Headwater Streams of the Oregon Coast Range written by Edward M. Salminen and published by . This book was released on 1990 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was undertaken to evaluate the occurrence and characteristics of undercut streambanks in forested headwater streams of the Oregon Coast Range. Undercut streambanks and associated reach characteristics were surveyed along 46 sample reaches (each 152 m in length) in 8 streams; all sample reaches occurred in unmanaged forested riparian areas. Drainage areas ranged from 0.3 to 16.6 km^2. At each undercut location length, surface area, volume, low-flow (summertime) volume, and maximum horizontal depth were measured. Individual undercuts had surface areas ranging from 0.3 to 27.7 m^2 with a mean value of 2.6 m^2, and lengths ranging from 1.2 to 15.2 m with a mean value of 5.0 m. The area undercut streambanks ranged from 0.0 to 27.4 m^2 / 100 m of stream, with an average value of 6.5 m^2 / 100 m. The proportion of bankfull channel area undercut ranged from 0.0 to 4.5%, with an average value of 1.1%. Reach length undercut ranged from 0.0 to 23.6%, with an average value of 6.2%. The values reported in this study are approximately mid-range in comparison to characteristics of undercut banks reported in studies from Alaska, Montana, and Wisconsin. The % of reach area covered by undercut streambanks in this study is approximately half of that provided by large woody debris. Outside channel bends had approximately 6 times more undercut streambanks than inside bends or straight sections. Streams having a sinuosity index greater than 1.15 averaged approximately twice as much % surface area undercut than streams having a sinuosity index less than 1.15. Number of undercuts and undercut characteristics were inversely correlated with channel gradient; significant differences occurring among 1%, 2-4%, and 5+% channel gradient classes. Streambanks ranging in height from 1-2 m had a higher occurrence of undercut streambanks than either lower or higher streambanks. Undercut streambanks were 4 times more common in "composite" than "non-composite" streambanks. Undercut characteristics appear to be correlated with valley segment type. Channel widths were, on average, significantly narrower at undercut sites when compared to reach average channel widths. However, it does not appear than width characteristics are a cause of undercutting. Based on field observations it appears that flow obstructions (gravel bars, boulders, large woody debris) have little impact on undercut characteristics. Both at-a-site and reach-level comparisons of undercut bank characteristics showed relatively strong correlations with streamside tree densities. Red alder (Alnus rubra) is the most prevalent species found in Coast Range riparian areas, and the most significant species in explaining reach-level differences in undercut characteristics. Sitka spruce (Picea sitchensis) is less common in riparian zones, but appears to be positively correlated with the proportion of reach area undercut.

Download or read book Shade Conditions Over Forested Streams in the Blue Mountain and Coast Range Georegions of Oregon written by Marganne Allen and published by . This book was released on 2001 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book Influences of Clearcut Logging on Macroinvertebrates in Perennial and Intermittent Headwaters of the Central Oregon Coast Range written by Janel Banks and published by . This book was released on 2005 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research was designed to broaden the understanding of how timber-harvest affects aquatic macroinvertebrates in perennial and intermittent headwater streams. This study compared emergent and benthic macroinvertebrate assemblages from 20 headwater streams in the central Oregon Coast Range that varied by harvest condition and flow duration. Through comparison of the community and functional characteristics of the macroinvertebrates in similar streams under different harvest conditions, logging impacts on adult and immature aquatic macroinvertebrates in perennial and intermittent streams were assessed. Adult insects emerging from the 20 study streams were collected using emergence traps set for four weeks in a 40-meter reach during three sampling periods: August-September 2003, October-November 2003, and April-May 2004. Adult aquatic insects were identified to genus and family taxonomic levels and results were expressed as number of individuals emerging per m2 per day. Benthic samples were taken from each reach in May 2004, insects and non-insects were identified to various taxonomic levels, and results were expressed as number of individuals per m2. Ten streams were located in catchments that were clearcut to the stream bank no more than a year before sampling began; three of these streams were intermittent and seven were perennial. Intermittent streams were summer-dry and retained surface-water for a minimum of eight months during the year, while perennial streams had surface flow year-round. The other ten streams (four intermittent and six perennial) were located in forested catchments that have not been logged for at least 34 years. The physical habitat of each stream reach was assessed in August 2003. Regardless of flow-duration or season, more aquatic insects emerged from streams in logged catchments. The emergence rate of Diptera, predominantly Chironomidae, was especially high from clearcut sites. More Trichoptera also emerged from clearcut sites. Ephemeroptera and Plecoptera did not emerge at rates that varied by logging condition. Plecoptera had higher emergence from intermittent than perennial sites in spring. Taxa richness was higher at clearcut sites, driven primarily by rare taxa encountered in less than 5 of the 10 clearcut sites. Emergent insect functional feeding group composition was affected by harvest condition with collector-filterers emerging at higher rates from clearcut sites. Examination of community patterns through nonmetric multidimensional scaling (NMS) ordination analyses indicated that emergent aquatic macroinvertebrate assemblages differ by season and by harvest condition. The duration of stream flow did not strongly influence adult assemblages. Channel dimensions (active channel and bankfull width) and catchment area were correlated with ordination-axes, but were not different between logged and forested sites. The amount of riparian cover (canopy, understory, and groundcover), stand age, slash, and stream cover were all considerably different between logged and forested sites and were highly influential on emergent assemblages. Substrate size was also influential on adult assemblages. Mean water temperature in summer, fall, and spring was highly correlated with seasonal variation in assemblages. Regardless of harvest-condition, intermittent streams had higher overall benthic macroinvertebrate density. Trichoptera had higher densities at intermittent sites than perennial sites, while Diptera, Plecoptera, and non-insects had similar densities between categories of flow duration and harvest condition. Benthic macroinvertebrate functional composition was also affected by flow-duration, with collector-filterers, collector-gatherers, and predators occurring at higher densities at intermittent sites than perennial sites. The densities of scrapers and shredders did not differ between classes of flow duration or harvest condition. The majority of taxa (72%) were common to both perennial and intermittent sites; however, taxa richness was lower at intermittent sites. NMS-ordination analyses of the benthic macroinvertebrates showed that community patterns differed by harvest condition within the perennial flow-duration class. Benthic communities of intermittent streams did not differ between harvest conditions. Channel dimensions (active channel and bankfull width), mean substrate diameter, percent stream-cover, mean water temperature, elevation, and percent small riparian trees influenced benthic community assemblages. The majority of perennial-clearcut sites had macroinvertebrate community patterns more similar to intermittent-forested and intermittent-clearcut streams than to perennial-forested sites. The two perennial-clearcut sites that did not have benthic assemblages similar to the other five perennial-clearcut sites had larger diameter substrate, higher elevation, larger catchment area, and cooler mean water temperature than other perennial-clearcut sites. This study provides evidence that Oregonâ??s current timber harvesting practices impact macroinvertebrate assemblages of perennial and intermittent headwaters in the Central Oregon Coast Range within a year following harvest. When the studied streams were clearcut to the streambank, there was increased emergence of adult macroinvertebrates, principally midges, at clearcut sites. Benthic assemblages differed primarily between intermittent and perennial flow-duration. However, within flow-classes, assemblages of benthic aquatic macroinvertebrates in perennial streams were impacted by clearcut logging to a higher degree than intermittent streams. Perennial-clearcut streams had different benthic assemblages from perennial-mature streams and perennial-clearcut streams with coarser substrate and cooler temperatures. Intermittent streams, which generally experience fewer flushing events and accumulate finer substrates than perennial streams, may be affected to a lesser degree by any sedimentation caused by logging activity. Correlations of emergent and benthic macroinvertebrate communities with the measured environmental gradients are suggestive that reduced canopy cover and substrate composition are major influential factors.

Download or read book Terrestrial Amphibian Distribution Habitat Associations and Downed Wood Temperature Profiles in Managed Headwater Forests with Riparian Buffers in the Oregon Coast Range written by Matthew R. Kluber and published by . This book was released on 2008 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Western forests have become increasingly fragmented landscapes dominated by young stands. Given that western Oregon forests largely consist of headwater systems, there is a need to better understand how headwater forest taxa and their habitats are impacted by forest management practices. Several amphibian species associated with forested headwater systems have emerged as management concerns. Forest management strategies, such as harvests that remove only part of the canopy and retention of riparian buffer strips, may help ameliorate some of the negative effects on amphibians in managed forests. Pre-existing site conditions, such as legacy downed wood, also may play a role in buffering the impacts of silvicultural practices on terrestrial amphibians. Downed wood is an important habitat component for many amphibians, because the cool, moist microclimates of downed wood can provide refugia for terrestrial amphibians during warmer summer months. However, downed wood habitat suitability is another emerging concern as the rate of input and size of downed wood declines in managed forests. As part of the USDI Bureau of Land Managements Density Management Study, we investigated how untreated streamside buffers modify impacts of upland thinning on headwater forest terrestrial amphibians and their habitat at three sites in the Oregon Coast Range. To further assess habitat associations of these animals, we conducted a field experiment to address amphibian cover use, including downed wood, moss and coarse and fine substrates. In addition, we examined how temperature profiles inside small- and large-diameter downed wood and soil temperatures differed from ambient air temperatures. Temperatures of wood and soil were monitored at different slope positions (near streams and upslope) and overstory regimes (thinned and unthinned stands) to assess potential habitat suitability and buffering capabilities against seasonal temperature extremes for plethodontid salamanders. Our results suggest that pre-existing site conditions (e.g., amount of rocky or fine substrate) play an important role in determining the response of terrestrial amphibians to upland forest thinning. However, retention of stream buffers is important in maintaining unaltered stream and riparian conditions. Moderate thinning and preservation of vital habitat in riparian and nearby upland areas by way of variable-width buffers (15 m minimum width) may be sufficient in maintaining suitable habitat and microclimatic conditions vital to amphibian assemblages in managed headwater forests. Additionally, logs of a wide size range and soils may provide sufficient protection against thermal extremes harmful to plethodontid salamanders in thinned stands with limited overstory. However, this alone cannot support plethodontid salamanders. These salamanders require exposed areas (e.g., leaf litter, soil surface, rock faces) where much of their foraging and well as courtship occurs. Partial retention of the canopy through moderate thinning coupled with variable-width riparain buffers that may increase in width when suitable terrestrial habitat is encountered, may provide sufficient microhabitat, microclimate, and protection in maintaining terrestrial amphibian assemblages in managed headwater forests.

Download or read book General Technical Report PNW GTR written by and published by . This book was released on 2006 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: