Riparian forest harvesting and its influence on benthic communities of small streams of sub-boreal British Columbia

2007 ◽  
Vol 37 (5) ◽  
pp. 907-918 ◽  
Author(s):  
K. Jill Melody ◽  
John S. Richardson
Keyword(s):  
Leaf Litter ◽  
Pacific Northwest ◽  
Riparian Forest ◽  
Benthic Communities ◽  
Forest Harvesting ◽  
Riparian Areas ◽  
The Pacific ◽  
Small Streams ◽  
Coastal Streams ◽  
Physical Features

Forest harvesting in riparian areas can alter the leaf-litter inputs, shading, and stability of small streams, and many of the details of these impacts are known for coastal streams of the Pacific Northwest. However, little is known about how small streams in the drier, continental areas of western North America respond to logging. We conducted a study of paired stream reaches (comparing one recently harvested (≤3 years) reach and two upstream, forested reaches in each of five streams) in which periphyton, detritus, macroinvertebrate abundance and biomass, and physical features were measured in summer and autumn. In general, recently harvested stream sections tended to be wider and contained more riffle areas than the upstream forested sections. The amounts of leaf litter and algae varied among streams and were not consistently greater or lesser in the forested sections than in the harvested sections. Though the variation in amounts within streams was mainly seasonal, amounts differed more among streams than between pairs of harvested and forested reaches. The communities of benthic invertebrates differed significantly between forested and harvested reaches, but often in opposite directions between streams. The magnitude and direction of differences observed between treatments, streams, or seasons were associated with the specific stream and the method of riparian harvesting used.

scholarly journals Evaluating Coexistence of Fish Species with Coastal Cutthroat Trout in Low Order Streams of Western Oregon and Washington, USA

Fishes ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Kyle D. Martens ◽  
Jason Dunham
Keyword(s):  
Pacific Northwest ◽  
Species Interactions ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
Single Species ◽  
The Pacific ◽  
Small Streams ◽  
Coastal Cutthroat Trout ◽  
Multiple Species ◽  
Low Order

When multiple species of fish coexist there are a host of potential ways through which they may interact, yet there is often a strong focus on studies of single species without considering these interactions. For example, many studies of forestry–stream interactions in the Pacific Northwest have focused solely on the most prevalent species: Coastal cutthroat trout. To examine the potential for interactions of other fishes with coastal cutthroat trout, we conducted an analysis of 281 sites in low order streams located on Washington’s Olympic Peninsula and along the central Oregon coast. Coastal cutthroat trout and juvenile coho salmon were the most commonly found salmonid species within these streams and exhibited positive associations with each other for both presence and density. Steelhead were negatively associated with the presence of coastal cutthroat trout as well as with coho salmon and sculpins (Cottidae). Coastal cutthroat trout most frequently shared streams with juvenile coho salmon. For densities of these co-occurring species, associations between these two species were relatively weak compared to the strong influences of physical stream conditions (size and gradient), suggesting that physical conditions may have more of an influence on density than species interactions. Collectively, our analysis, along with a review of findings from prior field and laboratory studies, suggests that the net effect of interactions between coastal cutthroat trout and coho salmon do not appear to inhibit their presence or densities in small streams along the Pacific Northwest.

Riparian tree fall directionality and modeling large wood recruitment to streams

2006 ◽  
Vol 36 (5) ◽  
pp. 1243-1254 ◽  
Author(s):  
Daniel J Sobota ◽  
Stanley V Gregory ◽  
John Van Sickle
Keyword(s):  
Pacific Northwest ◽  
Field Data ◽  
Riparian Forest ◽  
Large Wood ◽  
Riparian Trees ◽  
The Pacific ◽  
Riparian Tree ◽  
Individual Trees ◽  
Fall Direction ◽  
Recruitment Model

Directionality of tree fall in riparian forests can strongly influence predictions of large wood recruitment to streams, yet accuracy of this model parameter has rarely been assessed with field data. We measured fall directions of 1202 riparian trees distributed among 21 stream sites across the Pacific Northwest, USA. Fall directions were oriented towards the stream at 16 sites, upstream at four sites, and not distinguishable from random at one site. Average tree fall direction across sites was correlated with valley constraint (Spearman r = –0.53; p = 0.02), but variability of fall directions was not correlated with this variable. When grouped by species (six conifers and one deciduous), individual trees exhibited stronger tendency to have fallen towards the channel on steep hillslopes (>40%) than on moderately sloped landforms (<40%). Integration of field data into an established recruitment model indicated that 1.5 to 2.4 times more large wood (by number of tree boles) would be recruited to stream reaches with steep hillslopes than to reaches with moderate side slopes or flat banks, if riparian forest conditions are assumed to be constant. We conclude that stream valley topography should be considered in models that use tree fall directions in predictions of large wood recruitment to streams.

Riparian canopy type, management history, and successional stage control fluxes of plant litter to streams

2011 ◽  
Vol 41 (7) ◽  
pp. 1394-1404 ◽  
Author(s):  
Trent M. Hoover ◽  
Xavier Pinto ◽  
John S. Richardson
Keyword(s):  
Leaf Litter ◽  
Forest Type ◽  
Riparian Forest ◽  
Plant Litter ◽  
Coniferous Forests ◽  
Stand Age ◽  
Riparian Management ◽  
Management History ◽  
Forest Stream ◽  
Small Streams

The food webs of forest stream ecosystems are based primarily on cross-boundary flows of terrestrial plant litter (PL). As such, changes in the composition of riparian forest canopies can alter flows of PL, affecting the ecosystem functioning of adjacent streams. We measured seasonal changes in PL fluxes to 20 small streams flowing through temperate rain forests in southwestern British Columbia to determine how riparian forest type and riparian management history influence resource availability in these systems. Differences in PL fluxes among the four riparian forest types studied were most pronounced in the summer, when PL fluxes from clearcuts < riparian reserve strips and coniferous forests, and PL fluxes from deciduous-dominated forests < riparian reserve strips. PL fluxes also varied among seasons (spring < summer < autumn). Fluxes were similar in riparian reserve strips and coniferous forests of similar age, indicating that reserve strips maintain this crucial ecosystem process. Clearcutting of riparian forests dramatically increased light availability while reducing leaf litter inputs; these effects, however, lasted only a few years. As riparian forest stand age increased, inputs shifted from broadleaf to coniferous inputs, indicating a possible long-term decrease in the lability of the leaf litter resources available to stream consumers.

scholarly journals Effects of Forest Harvesting on Warm-Season Low Flows in the Pacific Northwest: A Review

2020 ◽  
Vol 4 (1) ◽  
pp. 29
Author(s):  
R.D. (Dan) Moore ◽  
Stefan Gronsdahl ◽  
Richard McCleary
Keyword(s):  
Pacific Northwest ◽  
Forest Disturbance ◽  
Fish Habitat ◽  
Warm Season ◽  
Forest Harvesting ◽  
Low Flow ◽  
Post Harvest ◽  
Low Flows ◽  
The Pacific ◽  
Paired Catchment

Paired-catchment studies conducted on small (< 10 km2) rain-dominated catchments revealed that forest harvesting resulted in a period of increased warm-season low flows ranging from less than five years to more than two decades, consistent with the results of stand-level studies and process considerations. Of the five paired-catchment studies in snow-dominated regions, none revealed a statistically significant change in warm-season low flows in the first decade following harvest, although two exhibited non-significant higher flows in August and September and one had lower flows. Two studies, one of rain-dominated catchments and one of snow-dominated catchments, found that summer low flows became more severe (i.e., lower) about two decades or so following harvest. These longer-term results indicate that indices such as equivalent clearcut area, as currently calculated using monotonic recovery curves, may not accurately reflect the nature of post-harvest changes in low flows. Studies focussed on medium to large catchments (tens to thousands of km2 in area) found either no statistically significant relations between warm-season low flows and forest disturbance, or inconsistent responses. Attempts to synthesize existing studies are hampered by the lack of a common low-flow metric among studies, as well as detailed information on post-harvest vegetation changes. Further fieldresearch and process-based modelling is required to help elucidate the underlying processes leading to the results from these paired-catchment studies and to enhance the ability to predict streamflow responses to forest harvesting, especially in the context of a changing climate. KEYWORDS: streamflow; forestry; low flows; fish habitat; hydrologic recovery

Nitrogen immobilization in decaying hardwood leaf litter as a function of initial nitrogen and lignin content

1982 ◽  
Vol 60 (11) ◽  
pp. 2263-2269 ◽  
Author(s):  
John D. Aber ◽  
Jerry M. Melillo
Keyword(s):  
Leaf Litter ◽  
Pacific Northwest ◽  
Nitrogen Availability ◽  
Lignin Content ◽  
Nitrogen Immobilization ◽  
Important Species ◽  
Hardwood Species ◽  
The Pacific ◽  
Successional Species ◽  
Using Data

Equations presented in an earlier paper, expressing organic matter and nitrogen dynamics in decomposing hardwood leaf litter, are extended to predict nitrogen immobilization patterns in litters of varying initial lignin and nitrogen content. A continuum of immobilization rates coincides with the successional status of the six northern hardwood species examined, with early successional species exhibiting the fastest rates. By using data from the literature, similar trends were found for southeastern hardwoods. Patterns for important species from Douglas-fir forests of the Pacific Northwest are quite different and may reflect differences in nitrogen availability following disturbance.

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