Type 5 Streams and Small Wetlands Literature Review

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What specific Type 5 stream structures or functions should be protected to meet department management goals?

Statements within this literature review are based on the reported findings from various published sources. Due to differences in sample design, methodology, geographical location, site characteristics, data analysis and interpretation, these statements may or may not agree with the results of other published reports. Despite contradictory results, one cannot say the findings of one author are more or less valid than another, due to the wide range of site characterists. Readers are urged to consider how and where information was collected when interpreting the value of the following conclusions. Headwater stream science is, in many ways, a relatively new field. Early observations and case studies may or may not represent widespread relationships.

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  • The Rhyacophila fenderi, Lepidostoma jewetti, Rhyacophila grandis, Psychoglypha avigo, Dolophilodes sisko, Pseudostenophylax edwarsi, and Wormaldia occidea utilized the temporary streams by synchronizing their growth period to the wet season, inhabiting seeps, and/or dispersing to permanent streams. (Anderson and Dieterich 1993).


  • The abundance, taxa richness, and community composition of hyporheic epibenthic populations was greatest in first order streams and decreased with increasing stream order. (Angradi 2001).


  • Temperatures increase faster in smaller channels than larger channels. (Beechie et al. 2000).


  • The breakdown rates of tree leaves is faster in catchments that have been logged than in catchments that are forested. The author speculates that there are fewer retentive obstacles in the logged catchments, so the leaves move more quickly during high flows, contributing to faster breakdown rates. (Benfield et al. 1991).


  • Debris dams hold up to 75% of the organic material in first order streams. This percentage decreases to 58% in second order streams, and 20% in third order streams. The low discharge rate of smaller streams can explain the high percentage of organic matter retention behind debris dams. (low energy = increased dam formation). (Bilby and Likens 1980).


  • Within streams less than 7 m wide, 40% of the wood was oriented perpendicular to the stream flow. However, in larger streams woody debris was oriented parallel to the stream flow. (Bilby and Ward 1989).


  • In small streams, 42% of the pools were plunge pools, and 40% of the in-stream wood accumulated sediment and organic material. (Bilby and Ward 1989).


  • Sediment and organic matter accumulates behind in-stream wood more frequently in small streams, than in larger streams. (Bilby and Ward 1989).


  • Marsh water temperatures were significantly warmer than spring source points. (Black 2001).


  • Hyporheic water temperatures were higher in the pasture sites than in the forested sites. (Boulton et al. 1997).


  • The native forest had a diverse invertebrate fauna composed mostly of surface benthos, which were not present in the pasture hyporheic zones. (Boulton et al. 1997).


  • Type 4 streams with no buffer were 2 - 8 degrees warmer than the non-harvested streams. After harvest, brush and slash provided 40% of the shade for the Type 4 streams without buffers. This study concluded that the downstream effect from small streams to larger streams is limited to 150m beyond the Type 4 stream. (Caldwell et al. 1991).


  • This study found 30m buffers effective for retaining small mammal populations (with the exception of Microtus oregoni (Creeping Vole)). In comparison to the control streams, the clearcut/no buffer sites had much lower populations of Sorex monticolus (dusky shrews), and Clethrionomys gappari (red backed voles). The researchers found an increased rate of bot fly infestation of small mammals in the unbuffered zones. Captures in the controls had no infestation, while animals in the 30m buffered zone had an intermediate rate of infestation. (Cockle et al. 2003).


  • Logging in high gradient streams increases the amount of slash within the channel, therefore increasing the potential for organic dams to form. (Coho and Burges 1994).


  • Type 4 and 5 streams are the most common places for dam formation. (Coho and Burges 1994).


  • Timber harvest increases the densities of "disturbance tolerant" macroinvertebrates; such as Sphaeriidae, Cammaridae, and Chironomidae species. Concurrently, overall macroinvertebrate diversity is decreased after timber harvest. This is contrary to the lower distribution of "disturbance tolerant" species in mature forest stands. (Cole et al. 2003).


  • Annual litter input declines with greater stream order (the smaller the stream the greater the litter input). (Connors and Naiman 1984).


  • The hyporheic zone in intermittent streams is not a refuge for invertebrates during the dry season. (Del Rosario and Resh 2000).


  • Intermittent stream fauna have a lower total density, taxon richness, and species diversity than perennial streams. The hyporheic resident invertebrates were unchanged (Sweltsa spp.) or decreased (Baetis, Parthina, Ceratopogonidae spp.), but densities of a permanent hyporheic resident (Archianelida spp.) increased during the drying period. The hyporheic fauna in the intermittent streams have lower densities, similar richness, but higher diversity of invertebrate species than perennial streams. (Del Rosario and Resh 2000).


  • In perennial streams the invertebrates move downstream with the drift, and the flow. In temporary streams the invertebrates move upstream, and vertically downward toward the hyporheic zone. (Delucchi 1989).


  • Permanent streams displayed larger temperature fluctuations than temporary streams. (Dieterich 1993).


  • Temporary streams have a high retentiveness feature. They have large quantities of allochthonous material despite low input. (Dieterich 1993).


  • Ephemeral streams filter out fine sediment from the water column that is delivered from roads. When there is a high level of precipitation, the channel floods and quickly widens. This flooding process filters the fine sediment through the soil rather than transporting it downstream. (Dieterich 1993).


  • Temporary and ephemeral streams channel nitrate from the surface water to the groundwater. (Dieterich 1993).


  • A large portion of the temporary stream fauna is composed of facultative species. These species are specially adapted, and have drought resistant life-stages that respond to different moisture conditions. (Dieterich 1993).


  • Invertebrate richness, and diversity can decrease in summer-dry streams, if flow duration, and habitat availability decreases. (Dieterich 1993).


  • Summer-dry streams have obligate stream species, such as Ephemeroptera, Plecoptera, and Trichoptera. It would be uncommon to find these species as obligate species in other parts of the world with unpredictable climatic patterns. (Dieterich 1993).


  • Mayflies and stoneflies exhibit prolonged hatching periods, and a asynchronous developmental life-stage in temporary streams. (Dieterich and Anderson 1995).


  • Ephemeral streams dry out very rapidly, leaving a few seeps, and retaining water for longer periods. The temporary streams loose water gradually, and about 5% of the overall channel is permanently wet, often with seeps, and pool habitats. (Dieterich and Anderson 1998).


  • Ephemeral streams retain fine sediment from roads and/or timber harvest, and incorporate it into larger sediment into the soil, which is then held by plants or grasses that grow during the dry season. (Dieterich and Anderson 1998).


  • Summer-dry streams have the capability to remove nitrate from the water column. (Dieterich and Anderson 1998).


  • 45% of the invertebrate species found in the forested streams occurred in summer seeps and pools. (Dieterich and Anderson 2000).


  • Temporary forested streams have a 20% greater species richness than was found in permanent streams. The author speculated that this may be due to several of the following factors; the close proximity to refugia, reduced predator pressure, and less competition from snails or other competitors. (Dieterich and Anderson 2000)


  • Even with the installation of buffers, air temperatures increased significantly in the riparian and upland zones. The results of this paper indicate that a 70m buffer strip is not enough to protect from increased air temperatures. (Dong et al. 1998).


  • The models developed during this study show that a 4°C increase in air temperature, will decrease relative humidity exponentially from 94% to about 77%. Conversely, vapor pressure deficit budgets increase exponentially. This may damage amphibian, moss, and lichen populations, which are dependent on vaporized water throughout their life cycles. (Dong et al. 1998).


  • Small ephemeral streams store fine sediments washed from the road surface. In-stream woody debris also traps, and retains sediment. (Duncan et al. 1987).


  • This study found that ephemeral streams temporarily retain coarser sized sediment (>0.063 mm) washed from the roads. (Duncan et al 1987).


  • High-gradient, ephemeral streams that flow during rain-on-snow melt tend to have irregular "steps." Short, low-gradient reaches are interspersed with longer, high-gradient reaches. Debris accumulates in short, low-gradient areas. The fluvial movement is pulsed, which guards against build-up of large amounts of debris, reducing the potential for sudden debris flows or torrents. (Gardner 1986).


  • According to the authors, riparian zones have greater species richness than uplands do. Various inventoried stands in western Oregon had twice as many species in the riparian zone compared to the uplands. (Gregory et al. 1991).


  • Riparian trees and herbaceous vegetation have extensive root networks that increase bank stability, and decrease erosion processes. (Gregory et al. 1991).


  • Large woody debris was the primary source of the in-stream barriers that stored sediment. (Grizzel and Wolff 1998).


  • Water temperature, and the rate of warming is highly variable in short headwater stream reaches (<300m). (Hagan 2000).


  • Macroinvertebrates living in first-order streams rely on terrestrial food sources, because instream algal growth is limited in areas with a closed canopy. Riparian areas that retain a mix of coniferous and decidious vegetation is optimal for macroinvertebrates, because coniferous needles alone make a poor quality food source. (Haggerty et al. 2002).


  • Wood plays an important role as a microhabitat for invertebrates. A number of taxa were found inside wood crevices, where they could avoid predation. (Haggerty et al. 2002).


  • Intermittent reaches had fewer amphibians than the perennial streams. Small torrent salamanders (Rhyacotriton spp.) inhabited a higher percentage of initiation reaches, and seeps, possibly using these habitats for reproduction. (Hayes and Quinn 2001).


  • Tree seedlings are much less abundant in hardwood dominated stands. (Hibbs and Bower 2001).


  • Hardwoods more frequently colonize terrace terrains, while conifers more typically occupy slopes. (Hibbs and Bower 2001).


  • Red alder (Alnus rubra) and bigleaf maple (Acer macrophyllum) seedlings were more common on mineral soils, while western hemlock (Tsuga heterophylla) and Pacific yew (Taxus brevifolia) seedlings were much more common on woody substrates. (Hibbs and Bower 2001).


  • Geomorphic relationships for larger streams can not be applied to smaller headwater streams. Large woody debris (>40cm in diameter) created less than 10% of the steps formed in headwater channels. The three major step forming agents in small streams included the following: small wood (between 10-40 cm), inorganic material, and organic debris (<10cm). (Jackson and Sturm 2001).


  • Small streams exhibit low fluvial movement. (Jackson and Sturm 2001).


  • The most commonly observed morphological difference in small streams vs. large streams was the abundance of step-riffles rather than pools. (Jackson and Sturm 2001).


  • The stream temperature in the two clearcut basins increased by seven degrees, which occurred earlier in the summer than in the control basin. The two biggest factors controlling stream temperature were short wave solar radiation, which is amplified after the removal of the riparian vegetation, and the conduction between the stream water and the nearby substrates/soils. The disturbed watersheds returned to pre-harvest temperature levels after 15 years. (Johnson and Jones 2000).


  • Sites where only overstory vegetation was removed generally had smaller increases in stream temperature than where the understory was also removed through burning or herbicide treatments. (Johnson and Jones).


  • Dicamptodon tenebrosus living in buffered streams, behaved similarly to those found in forested habitats. However, in clearcut areas, this species stays closer to the stream channel. Consequently, their home ranges are smaller, they stay in refugia longer, and move more often during rain events. (Johnston and Frid 2002).


  • Besides habitat, riparian buffers provide shade, bank stability, and continuous inputs of organic matter. Buffers also reduce runoff, and act as barriers to logging debris. (Kelsey and West 2001).


  • Berry producing shrubs should always be retained in the buffer, because they provide an important food source for many species. (Kelsey and West 2001).


  • Approximately 29% of riparian wildlife species are classified as riparian obligates, which means they need riparian habitat to survive. (Kelsey and West 2001).


  • Not only does the riparian zone provide habitat for wildlife, it also serves as refuge from predators and as a topographical landmark for navigation (especially for birds). (Kelsey and West 2001).


  • Riparian systems support generalists, exotic species, and riparian obligates (which are mostly amphibians). (Kelsey and West 2001).


  • Bats, beavers, minks, moles, muskrats, river otters, and many birds regularly inhabit riparian areas. (Kelsey and West 2001).


  • Forbs, herbs, and rocks are in greater abundance in the riparian zone. (Kelsey and West 2001).


  • Tailed frogs (Ascaphus truei) respond negatively to clear cutting, even when buffers are installed. (Kelsey and West 2001).


  • Coarse particulate organic matter (CPOM), and fine particulate organic matter (FPOM) are positively correlated to the daily stream discharge. (Kiffney et al. 2000).


  • Dissolved organic matter (DOM) is inversely related to discharge (DOM increases as discharge decreases). (Kiffney et al. 2000).


  • Seasonal and annual variations in precipitation and stream discharge, can either increase or decrease the amount of CPOM, FPOM, DOM, and epilithic organic matter found in the stream. (Kiffney et al. 2000).


  • Anthropogenic barriers, such as suspended culverts, should be reduced or eliminated to allow for full dispersal of Oncorhynchus spp. to their natural distributions. (Latterell et al. 2003).


  • Intermittent streams located in old-growth forests exhibited the following characteristics: drying began in May or June, and ended by July; lengthy annual flow durations; cool and stable stream temperatures; coarse substrates; streamside vegetation consisting of overstory and understory plants that are associated with both dry, and wet conditions; and low to moderate densities of large woody debris. (Lee 1997).


  • Intermittent streams located in young stands exhibited the following characteristics: dry 1-2 months later than the old growth stand, higher daily stream temperatures, finer substrates, more deciduous and herbaceous understory, and less moderately decayed large woody debris. (Lee 1997).


  • Intermittent streams were dominated by Rhyacotriton cascadae (Cascade torrent salamander), and Plethodon dunni (Dunn's salamander). Rhyacotriton cascadae's were mostly found in shallow, slow moving waters, and in seeps. Plethodon dunni's were found in seeps, and along stream banks. (Lee 1997).


  • The intermittent streams contained mostly larval, and juvenile amphibians. The author speculates that these streams might be used for rearing habitats. (Lee 1997).


  • Small streams can serve as large sediment reservoirs in between debris flow periods. The author suggests that if these small streams are depleted of woody debris, the sediment storage capacity will greatly decrease, transporting a chronic source of sediment downstream. (May 2002).


  • Woody debris in colluvial channels functioned as sediment storage points (40%), small wood storage (20%), or had no current function at all. (May and Gresswell 2003).


  • Fluvial redistribution of woody debris is less common in colluvial channels with steep gradients, because the stream channel lacks the energy necessary to transport these materials. Therefore, woody debris is stored in small streams for an extended period of time, and only episodically moves downstream during catastrophic events, such as debris flows. (May and Gresswell 2003).


  • Small streams without woody debris, may become chronic sources of sediments to downstream reaches. (May and Gresswell 2003).


  • In both canopied and uncanopied stream reaches, true flies (Diptera spp.)and mayflies (Ephemeroptera spp.) were the most abundant invertebrates flushed from the stomachs of coho salmon, cutthroat and rainbow trout (Oncorhynchus spp. ). (Meehan 1996).


  • Large woody debris is important in maintaining channel integrity and floodplain processes. (Naiman et al. 2001).


  • Large woody debris provides sights for colonization by conifer and decidious trees and shrubs. (Naiman et al. 2001).


  • Coarse woody debris (CWD) in first- and second-order streams, usually decomposes or fragments into smaller pieces. (Nakamura and Swanson 1993).


  • Hardwood dominated riparian areas, were likely to have existed before the onslaught of forest disturbance in the 19th and 20th centuries. (Nierenberg and Hibbs 2000).


  • Headwater streams can potentially provide breeding habitat for terrestrial amphibians, such as newts (Taricha granulosa) and ensantinas (Ensatina eschscholtzii). (Olson et al. 2000).


  • In this study, trout (Oncorhynchus spp.) and Pacific giant salamanders (Dicamptodon tenebrosus) were associated with larger, wetter streams. Conversely, torrent salamanders (Rhyacotriton spp.) were more common in smaller, dryer streams. (Olson et al. 2000).


  • Tailed frogs (Ascaphus truei) were found to have a positive association with narrow, discontinuous stream reaches, while Pacific giant salamanders (Dicamptodon tenebrosus) had a negative association with the same habitat type. (Olson et al. 2000).


  • All arthropods found in the uplands, were also found in the riparian zone. However the riparian zone had greater arthropod abundance and diversity. This availability of prey species probably contributes to greater near stream amphibian diversity. (Olson et al. 2000).


  • Snag structures should recieve protection during harvest. This can be done by adding "skips" or leave tree islands into the harvest plan. (Olson et al. 2002).


  • Mycorrhizal relationships and lichen hotspots are important components of diverse forest ecosystems. These resources can be maintained in leave tree islands. (Olson et al. 2002).


  • Headwater streams remove ammonium from the water column within 10-100 meters. (Peterson et al. 2001).


  • Small streams also remove nitrate, but it takes 5-10 times longer than the removal of the ammonium. (Peterson et al. 2001).


  • Lichens that were abundant in riparian hotspots were found much less frequently in adjacent uplands. (Peterson and McCune 2003).


  • Nitrogen-fixing cyanolichens are associated with riparian hotspots and hardwood trees. (Peterson and McCune 2003).


  • This study found that Lobaria pulmonaria is more closely associated with hardwoods, rather than old-growth, as previously believed. (Peterson and McCune 2003).


  • Large woody debris does not play a role in sediment storage in 1st order streams because these channels are narrow, which prevents the logs from lying in a position in which they could store sediment. (Potts and Anderson 1990).


  • First order streams have a greater number of organic obstructions than are found in third order streams. The author speculates that third order streams have a deeper and wider channel limiting the construction of small debris formations. (Potts and Anderson 1990).


  • Organic debris in intermittent and ephemeral streams, plays an important role in channel stability, and sediment storage . (Potts and Anderson 1990).


  • Species richness was similar between perennial and intermittent streams, but lower in ephemeral streams. (Price et al. 2003)


  • Intermittent streams provide a unique habitat were species have adapted to low-flow periods and occasional drying. (Price et al. 2003).


  • Macroinvertebrates of the "shredder" feeding group, were more abundant in smaller intermittant and ephemeral streams. (Price et al. 2003).


  • Aquatic and terrestrial amphibians were most abundant in old forests, least abundant in young forests, and intermediate in mature forests, including buffered and thinned sites. (Raphael et al. 2002).


  • Amphibians and fish are most sensitive to physical, instream attributes, such as elevation, gradient, and bedrock material. (Raphael et al. 2002).


  • Aquatic amphibians utilize instream coarse woody debris as refuge from predators. (Rundio et al. 2002).


  • Refuge availability for Dicamptodon species is probably important to avoid predator/prey interactions with Cutthroat trout. (Rundio et al. 2002).


  • Basalt geology produces more of the coarse substrates (cobble, gravel) that Rhyacotriton kezeri species prefer. High gradients are prefered by this species because fine sediments do not accumulate in the interstitial spaces between cobble and gravel substrates, where R. kezeri is often found. (Russell et al. 2004).


  • Resource reduction inluences invertebrate drift. The treated stream (litter exclusion) had a lower drift density, but the proportion of benthic animals drifting was greater. The author concludes that drift may be used as a mechanism for invertebrates to locate other food resources. (Siler et al. 2001).


  • After harvest, wood loading along type 5 streams is moderate to high. Most of the pieces are buried, and/or decayed. (Soicher 1999).


  • Key woody debris pieces provide stability for small streams by creating steps, storing sediment, and dissipating hydraulic energy. (Soicher 1999).


  • Instream large woody debris provides nutrients, refuge, and a deposition site for organic matter (food) for aquatic organisms. (Swanson and Fredriksen 1982).


  • This study states that juvenile tailed frogs stay closer to the stream in clearcuts, but adults seemed mostly unaffected by canopy cover. Howerver, juveniles moved farther from the stream in old growth forests, than in clearcuts. This study suggests that tailed frog larvae may initially benefit from clearcut harvesting, but juveniles and adults may not. This is due to impaired land movements which would reduce foraging, and increase competition. (Wahbe et al. 2004).


  • Vegetation in the riparian zone is influenced by "water availability, disturbance regime, and levels of solar radiation." (Waters et al. 2001).


  • 90% of the small mammals captured, were taken from the Black Hills sites. 87% of the amphibians found, were from the Willapa Hills sites. (Wilk and Raphael 2002).


  • Seven species of shrews were detected. The most common shrews found were Neurotrichus gibbsii (shrew mole), and Sorex trowbridgii (Trowbridge's shrew). Four species of amphibians were also found, the most common one being Rhyacotriton kezeri (Torrent salamander). (Wilk and Raphael 2002).


  • One metamorphosed Dicamptodon copei (Cope's giant salamander) was captured and 2 others were detected at the Willapa Hills site. (Wilk and Raphael 2002).


  • The invertebrates that live in temporary waters have a flexible life cycle, exhibiting temperature-linked development, possession of a diapausing or otherwise protected egg, and high powers of dispersal (Williams 1996).


  • Ephemeroptera, Hemiptera, Coleoptera, Trichoptera and Diptera are abundant in temporary waters. The diversity of invertebrates is lower in temporary waters than in perennial waters (Williams 1996).


  • Invertebrate faunas inhabiting these temporary streams belong to three groups: permanent stream faunas with a wide range of tolerance, facultative species, and specialized temporary stream faunas restricted to this type of habitat (Williams and Hynes, 1977).


  • Precipitation, infiltration rate, and substrate play a significant role when discussing the ecology of temporary streams. The groundwater table can move up or down in response to recharge. It is controlled by sudden precipitation, consequent overland flow and/or interflow. When the groundwater table recedes, the pools will vanish due to evaporation (Williams and Hynes 1977).



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