Stream Channel Morphology and Woody Debris in Logged and Unlogged Basins of Western Washington

1994 ◽  
Vol 51 (1) ◽  
pp. 37-51 ◽  
Author(s):  
Stephen C. Ralph ◽  
Geoffrey C. Poole ◽  
Loveday L. Conquest ◽  
Robert J. Naiman
Keyword(s):  
Woody Debris ◽  
Timber Harvest ◽  
Channel Morphology ◽  
Habitat Characteristics ◽  
Low Flow ◽  
Stream Channels ◽  
Management Objectives ◽  
Western Washington ◽  
Basin Area ◽  
Pool Area

Channel morphology and habitat characteristics of stream segments draining unharvested old-growth forests were compared with those from streams within intensively and moderately logged basins. Sites covered a broad geographic range in western Washington State and were stratified by basin area and channel gradient. Although the number of pieces of large woody debris (LWD) within stream channels was unaffected by timber harvest, there was a clear reduction in LWD size in harvested basins. Timber harvest also resulted in a shift in location of LWD towards the channel margins, outside the low-flow wetted width of the channel. Intensive harvest simplified channel habitat by increasing riffle area and reducing pool area and depth, although the commonly used index of pool-to-riffle ratio appears inadequate to document these changes. Given the natural variation from stream to stream, we conclude that simple counts of instream LWD and channel units (habitat types) are not useful as management objectives. Instead, these attributes should be used collectively as indicators of the complexity and stability of in-stream habitat with respect to the specific channel and valley geomorphology.

Effects of large woody debris placement on stream channels and benthic macroinvertebrates

1997 ◽  
Vol 54 (4) ◽  
pp. 931-939 ◽  
Author(s):  
R H Hilderbrand ◽  
A D Lemly ◽  
C A Dolloff ◽  
K L Harpster
Keyword(s):  
Woody Debris ◽  
Large Woody Debris ◽  
Stream Channels ◽  
High Gradient ◽  
Restoration Technique ◽  
Randomized Design ◽  
Random Placement ◽  
Proportional Increase ◽  
Stream Pool ◽  
Pool Area

Large woody debris (LWD) was added as an experimental stream restoration technique in two streams in southwest Virginia. Additions were designed to compare human judgement in log placements against a randomized design and an unmanipulated reach, and also to compare effectiveness in a low- and a high-gradient stream. Pool area increased 146% in the systematic placement and 32% in the random placement sections of the low-gradient stream, lending support to the notion that human judgement can be more effective than placing logs at random in low-gradient streams. Conversely, the high-gradient stream changed very little after LWD additions, suggesting that other hydraulic controls such as boulders and bedrock override LWD influences in high-gradient streams. Logs oriented as dams were responsible for all pools created by additions regardless of stream or method of placement. Multiple log combinations created only two pools, while the other seven pools were created by single LWD pieces. Total benthic macroinvertebrate abundance did not change as a result of LWD additions in either stream, but net abundances of Plecoptera, Coleoptera, Trichoptera, and Oligochaeta decreased, while Ephemeroptera increased significantly with the proportional increase in pool area in the low-gradient stream.

scholarly journals Woody debris as a confounding factor in interpreting the width of spring-fed streams

2019 ◽  
Author(s):  
Dana Ariel Lapides ◽  
Michael Manga
Keyword(s):  
Woody Debris ◽  
Unit Length ◽  
Channel Morphology ◽  
Climate Data ◽  
Stream Channels ◽  
Stream Width ◽  
Order Of Magnitude ◽  
High Resolution Satellite Imagery ◽  
The Impact

Abstract. Spring-fed streams throughout volcanic regions of the western United States exhibit larger widths than runoff-fed streams with similar discharge. Due to the distinctive damped hydrograph of spring-fed streams, large woody debris is less mobile in spring-fed than runoff-fed stream channels. The consequent long residence time of wood in spring-fed streams allows wood to potentially have long-term impacts on channel morphology. We used high-resolution satellite imagery in combination with discharge and climate data from published reports and publicly available databases to investigate the relationship between discharge, woody debris length, and channel width in 38 spring-fed and 20 runoff-fed streams. We identify an order of magnitude more logjams than single logs per unit length present in runoff-fed streams as compared to spring-fed streams. Histograms of log orientation in spring-fed streams additionally confirm that single logs are immobile in the channel so that the impact of single logs on channel morphology could be pronounced in spring-fed streams. Based on these observed differences, we hypothesize that there should be a difference in channel morphology. We find that spring-fed streams in our study are about 2 times wider than runoff-fed streams with similar mean discharge. Additionally, a model for stream width in spring-fed streams based solely on length of wood is a better model than one derived from discharge or including both discharge and wood length. This study provides insights into controls on stream width in spring-fed streams by identifying a strong correlation between wood length and stream width and confirming that spring-fed streams are significantly wider than runoff-fed streams.

Coarse woody debris in oak forested stream channels in the central Himalaya

Ecoscience ◽  
1998 ◽  
Vol 5 (1) ◽  
pp. 128-131 ◽  
Author(s):  
Hem C. Rikhari ◽  
Surendra P. Singh
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Central Himalaya ◽  
Stream Channels ◽  
Forested Stream

scholarly journals Ponderosa Pine Regeneration, Wildland Fuels Management, and Habitat Conservation: Identifying Trade-Offs Following Wildfire

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 286 ◽  
Author(s):  
Victoria Donovan ◽  
Caleb Roberts ◽  
Carissa Wonkka ◽  
David Wedin ◽  
Dirac Twidwell
Keyword(s):  
Species Richness ◽  
Ponderosa Pine ◽  
Fire Management ◽  
Woody Debris ◽  
Pine Forest ◽  
Habitat Conservation ◽  
Fuels Management ◽  
Management Objectives ◽  
Pine Regeneration ◽  
Ponderosa Pine Forest

Increasing wildfires in western North American conifer forests have led to debates surrounding the application of post-fire management practices. There is a lack of consensus on whether (and to what extent) post-fire management assists or hinders managers in achieving goals, particularly in under-studied regions like eastern ponderosa pine forests. This makes it difficult for forest managers to balance among competing interests. We contrast structural and community characteristics across unburned ponderosa pine forest, severely burned ponderosa pine forest, and severely burned ponderosa pine forest treated with post-fire management with respect to three management objectives: ponderosa pine regeneration, wildland fuels control, and habitat conservation. Ponderosa pine saplings were more abundant in treated burned sites than untreated burned sites, suggesting increases in tree regeneration following tree planting; however, natural regeneration was evident in both unburned and untreated burned sites. Wildland fuels management greatly reduced snags and coarse woody debris in treated burned sites. Understory cover measurements revealed bare ground and fine woody debris were more strongly associated with untreated burned sites, and greater levels of forbs and grass were more strongly associated with treated burned sites. Wildlife habitat was greatly reduced following post-fire treatments. There were no tree cavities in treated burned sites, whereas untreated burned sites had an average of 27 ± 7.68 cavities per hectare. Correspondingly, we found almost double the avian species richness in untreated burned sites compared to treated burned sites (22 species versus 12 species). Unburned forests and untreated burned areas had the same species richness, but hosted unique avian communities. Our results indicate conflicting outcomes with respect to management objectives, most evident in the clear costs to habitat conservation following post-fire management application.

Modern Alluvial History of the Paria Rver Drainage Basin, Southern Utah

1986 ◽  
Vol 25 (3) ◽  
pp. 293-311 ◽  
Author(s):  
Richard Hereford
Keyword(s):  
Sediment Yield ◽  
Drainage Basin ◽  
River Channel ◽  
High Flow ◽  
Low Flow ◽  
Vertical Accretion ◽  
Important Process ◽  
Stream Channels ◽  
History Of ◽  
Peak Flood

Stream channels in the Paria River basin were eroded and partially refilled between 1883 and 1980. Basin-wide erosion began in 1883; channels were fully entrenched and widened by 1890. This erosion occurred during the well-documented period of arroyo cutting in the Southwest. Photographs of the Paria River channel taken between 1918 and 1940 show that the channel did not have a floodplain and remained wide and deep until the early 1940s. A thin bar (<50 cm), now reworked and locally preserved, was deposited at that time. Basin-wide aggradation, which began in the early 1940s, developed floodplains by vertical accretion. The floodplain alluvium, 1.3–3 m thick. consists of two units recognizable throughout the studied area. An older unit was deposited during a time of low flow and sediment yield whereas the younger unit was deposited during times of high flow, sediment yield, and precipitation. Tree-ring dating suggests that the older unit was deposited between the early 1940s and 1956, and the younger between 1956 and 1980. The units are not time transgressive, suggesting that deposition by knickpoint recession was not an important process. High peak-flood discharges were associated with crosion and low flood discharges with aggradation. The erosional or aggradational mode of the streams was determined principally by peak-flood discharge, which in turn was controlled by precipitation.

Influence of large woody debris on channel morphology and dynamics in steep, boulder-rich mountain streams, western Cascades, Oregon

Geomorphology ◽  
2003 ◽  
Vol 51 (1-3) ◽  
pp. 187-205 ◽  
Author(s):  
John M Faustini ◽  
Julia A Jones
Keyword(s):  
Woody Debris ◽  
Channel Morphology ◽  
Large Woody Debris ◽  
Mountain Streams
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