Type 5 Streams and Small Wetlands Literature Review

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How do Type 5 streams contribute to the riparian conservation strategy?

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.

Click on the citation following each statement to view the annotated bibliography

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  • The data suggested that invertebrate inputs are higher in these Alder (Alnus rubra) dominated stands of south eastern Alaska. As in western Washington, these streams are classified as relatively unproductive. (Allan et al. 2003).


  • Approximately 1/3 of juvenile coho (Oncorhynchus kisutch) diets consisted of terrestrial invertebrates. (Allan et al. 2003).


  • Riparian buffers with a heterogenous overstory and understory supply "variation in quantity, composition, and timing of terrestrial invertebrates." (Allan et al. 2003).


  • Depletion or exclusion of terrestrial prey, usually results in a behavioral response by fish populations to emmigrate to areas were prey is more abundant. (Baxter et al. 2005).


  • Fish prefer terrestrial prey over benthic prey, because benthic organisms are often smaller and more difficult to catch. (Baxter et al. 2005).


  • Fish production was greater in the clear cut/ buffered site, because the fish populations depend on food delivered from allochthonous pathways. (Bilby and Bisson 1992).


  • Fish are more closely associated with in-stream habitat, rather than with riparian conditions. For example, Cutthroat trout (Oncorhynchus clarki clarki) prefer streams with adequate pool habitat. This species in not a good indicator of riparian health.(Bisson et al. 1996)


  • Torrent sculpins (Cottus rhotheus) were found more often in streams with an abundance of pools and mid-seral riparian areas. (Bisson et al. 1996).


  • Coastrange sculpins (Cottus aleuticus) are more common in low elevation streams with adequate pool habitat. C. aleuticus is rarely found in late-seral riparian areas. (Bisson et al. 1996).


  • Tailed frogs (Ascaphus truei) are associated with late-seral riparian forests. (Bisson et al. 1996).


  • The authors agree that fish are generally less abundant in old growth streams with high elevations, and a history of landslides. (Bisson et al. 1996).


  • Amphibians are more abundant in high elevation, steep gradient, montane streams, than in low elevation, coastal streams. The researchers also found that the amphibians favored late-seral over early-seral riparian forests. This suggests that amphibian populations are negatively affected by timber removal. (Bisson et al. 1996).


  • Coho use ephemeral, and intermittent streams for off-channel overwintering habitat. Overwintering in small tributaries increases their chances of survival because it prevents the entire stock from being wiped out by a catastrophic event, such as a debris torrent. (Brown and Hartman 1988).


  • By using a stream flow mixing equation, it was determined that warmer Type 4 waters would not increase Type 3 water temperatures by more than 0.49 degrees celsius, provided that the Type 3 reach is at least 7km long. Type 3 waters recieving warmer inflows, will go back to equilibrium within 150m of the Type 4 confluence. (Caldwell et al. 1991).


  • Landslides and debris torrents are sometimes triggered from forest related practices. This in turn, increases stream sediment yields. Excessive sediment levels can have a range of effects on Coho salmon. For example, the survival of eggs is dependent on well oxygenated water; the infiltration of fine sediment may lead to egg and alevin suffocation. Disproportioned suspended sediment levels can also lead to increased stress in juvenile fish. Overwintering refugia for smolts may be reduced from increasing sediment yields. Additionally, coarse sediment can decrease summer rearing habitats. And finally, the removal of woody debris can decrease stream bank stability, which leads to more sediment input. Pool frequency is often reduced by the above mentioned process. (Cederholm and Reid 1987).


  • Dam break floods start in first-fifth order streams, and propagate to six order streams. (Coho and Burges 1991).


  • Annual litter input declines with greater stream order (the smaller the stream the greater the litter input). This suggests that these low order streams may deliver organic material downstream to higher order channels. (Connors and Naiman 1984).


  • Summer low flows are detrimental to salmon because as stream temperatures increase, dissolved oxygen is reduced. As a result, juvenile steelheads leave riffles, and go into pools where they face increased competition with more aggressive Cohos. (Hicks et al. 1991).


  • Alders provide a good food source for fish and other aquatic organisms. But these benefits are counteractive in terms of woody debris input, because alder is generally smaller and has a shorter mean residence time as woody debris, compared to conifers. (Johnson and Edwards 2002).


  • In the Pacific Northwest, alder is not comparable to coniferous woody debris inputs because it is generally smaller in diameter and has a shorter mean residence time. (Johnson and Edwards 2002).


  • The upper distribution limits of Oncorhynchus spp. (Rainbow and Cutthroat Trout) is less influenced by logging practices and more influenced by physical factors, such as channel gradients, pool abundance, and wetted channel width. (Latterell et al. 2003).


  • Trout (Oncorhynchus spp.) are commonly found in gradients exceeding 10%. This study found that trout can access channels with up to 22% gradients. (Latterell et al. 2003).


  • An essential role of headwater streams is to process coarse particulate organic matter and small organic debris, for downstream uptake of nutrients and carbon by aquatic organisms. (MacDonald and Ritland 1989).


  • Transpiration was higher in young growth stands, compared to old growth stands. (Moore et al. 2004).


  • Water use decreases in climax forests due to "age-related changes in whole tree hydraulic conductance, species-related differences in water use and structurally related changes in sapwood area distribution within stands." (Moore et al. 2004).


  • Headwater channels are important sources of sediments, water, and nutrients for downstream reaches. (Moore and Richardson 2003).


  • Large organic debris dams store sediment, while also providing structure, and channel stability to steep low order streams. Disrupting these dams would increase the amount of bedload transported downstream, possibly effecting salmon and/or juvenile rearing habitat. (O'Connor and Hall 1994).


  • Nitrogen is removed from the water column quicker in smaller headwater streams. As nitrogen levels increase in small streams the capacity to effectively retain and transform these molecules may become inhibited, allowing a greater amount of inorganic nitrogen to move downstream. (Peterson et al. 2001).


  • Altering stream flow can have a number of negative cumulative effects including: re-distributing woody debris, alternating the geometry of the channel, and increasing stream scour frequency. These effects might be worsened in areas such as in the transient snow zone, where storms may produce rapid storm run-off or in regions of high precipitation, potentially affecting channel morphology. (Peterson et al. 1992).


  • Young alder stands export more prey to downstream linkages, than do young conifer stands. (Piccolo and Wipfli 2002).


  • The results show that the birds, fish, and small mammals sampled in this study, persist at buffered and unbuffered sites. However, amphibians were found to be more sensitive to harvesting. Amphibian abundance and diversity was highest in old-growth settings, lowest in young unbuffered sites, and intermediate at second growth sites. (Raphael et al. 2002).


  • The diameter of large woody debris is the most determinant characteristic that influences instream pool formation. Pool formation is a function of total woody debris and diameter distribution. (Rosenfeld and Huato 2003).


  • Larvae of Pacific giant salamanders (Dicamptodon tenebrosus) appear to have behavioral defenses, rather than chemical defenses, to cutthroat trout (Oncorhynchus clarki) because Dicamptodon's were proven palatable to cutthroat trout. When cutthroat chemical cues are present, Dicamptodon larvae tend to take cover in refugia. (Rundio et al. 2002).


  • Bull trout found in mountainous terrain are affected by bedload scour induced by rain, and snow events. (Shellberg 2001).


  • Basin wide examination of water, nutrient, and sediment movement is important to connect upstream forestry practices to downstream fishery resources. (Swanson et al. 1987).


  • Steep basins are more sensitive to management activities because of the frequency of mass wasting. (Swanson et al. 1987).


  • Debris flows in low order channels can block fish passage, but this occurs at the upper extent of their distribution. (Swanson et al. 1987).


  • Fish can occupy gradients ranging from 3 - 35%, although the majority are found in gradients around 15%. (Trotter 2000).


  • Fish that occur in the uppermost headwater reaches (ephemeral and intermittent) include the following: Oncorhynchus clarkii (cutthroat trout), Oncorhynchus mykiss (native rainbow trout), Salvelinus fontinalis (non-native brook trout), Salvelinus confluentus (bull trout), and Cottus spp. (sculpins). (Trotter 2000).


  • Detritus and macroinvertebrates from headwater streams, most likely contribute substantial amounts of food to downstream aquatic organisms, particularly salmonid species. (Wipfli and Gregovich, 2002).



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