Factors affecting distribution of wood, detritus, and sediment in headwater streams draining managed young-growth red alder – conifer forests in southeast Alaska

2006 ◽  
Vol 36 (3) ◽  
pp. 725-737 ◽  
Author(s):  
Takashi Gomi ◽  
Adelaide C Johnson ◽  
Robert L Deal ◽  
Paul E Hennon ◽  
Ewa H Orlikowska ◽  
...  
Keyword(s):  
Headwater Streams ◽  
Mass Movement ◽  
Timber Harvesting ◽  
Riparian Forests ◽  
Spatial And Temporal Variability ◽  
Large Wood ◽  
Short Channel ◽  
Red Alder ◽  
Southeast Alaska ◽  
Young Growth

Factors (riparian stand condition, management regimes, and channel properties) affecting distributions of wood, detritus (leaves and branches), and sediment were examined in headwater streams draining young-growth red alder (Alnus rubra Bong.) – conifer riparian forests (< 40 years old) in southeast Alaska. More riparian red alder were found along streams affected by both timber harvesting and mass movement than in streams affected by timber harvesting alone. Young-growth stands produced little large wood material (diameter ≥10 cm) and had little effect on altering the size distribution of functional large wood in channels, although more alder wood pieces were found in streams with greater numbers of riparian alder trees. Legacy wood pieces (>40 years old) remained in channels and provided sites for sediment and organic matter storage. Despite various alder–conifer mixtures and past harvesting effects, the abundance of large wood, fine wood, and detritus accumulations significantly decreased with increasing channel bank-full width ( 0.5–3.5 m) along relatively short channel distances (up to 700 m). Changes in wood, detritus, and sediment accumulations together with changes in riparian stand characteristics create spatial and temporal variability of in-channel conditions in headwater systems. A component of alder within young-growth riparian forests may benefit both wood production and biological recovery in disturbed headwater stream channels.

Relations between red alder composition and understory vegetation in young mixed forests of southeast Alaska

2006 ◽  
Vol 36 (3) ◽  
pp. 738-748 ◽  
Author(s):  
Thomas A Hanley ◽  
Robert L Deal ◽  
Ewa H Orlikowska
Keyword(s):  
Carrying Capacity ◽  
Basal Area ◽  
Picea Sitchensis ◽  
Understory Vegetation ◽  
Wildlife Habitat ◽  
Red Alder ◽  
Southeast Alaska ◽  
Net Production ◽  
Understory Biomass ◽  
Young Growth

Interest in mixed red alder (Alnus rubra Bong.) – conifer young-growth stands has grown in southeast Alaska, USA, because they appear to provide much more productive understory vegetation and wildlife habitat than do similar-aged pure conifer stands. We studied understory vegetation in nine even-aged young-growth stands (38–42 years old) comprising a gradient of red alder – conifer overstory composition, with red alder ranging from 0% to 86% of stand basal area. Conifers were Sitka spruce (Picea sitchensis (Bong.) Carr.), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don). We measured understory biomass and net production (current annual growth) in each stand by species and plant part and estimated carrying capacity for black-tailed deer (Odocoileus hemionus sitkensis Cowan) with a food-based habitat model. Highly significant positive relations (P < 0.002) were found between red alder basal area and all of the following: total understory biomass (r2 = 0.743), net production of shrubs (r2 = 0.758) and herbs (r2 = 0.855), and summer carrying capacity for deer (r2 = 0.846). The high correlation between red alder and herbaceous production is especially important, because herbs are least abundant and most difficult to maintain in young-growth conifer forests of this region. Red alder offers prospects for increasing understory vegetation biomass and its food value for deer and other wildlife when included as a hardwood overstory species in mixed hardwood–conifer young-growth forests.

Does red alder (Alnus rubra) in upland riparian forests elevate macroinvertebrate and detritus export from headwater streams to downstream habitats in southeastern Alaska?

2002 ◽  
Vol 59 (3) ◽  
pp. 503-513 ◽  
Author(s):  
Jack J Piccolo ◽  
Mark S Wipfli
Keyword(s):  
Forest Canopy ◽  
Headwater Streams ◽  
Riparian Forest ◽  
Woody Debris ◽  
Timber Harvest ◽  
Negative Effects ◽  
Red Alder ◽  
Tongass National Forest ◽  
Young Growth ◽  
Canopy Type

We assessed the influence of riparian forest canopy type on macroinvertebrate and detritus export from headwater streams to downstream habitats in the Tongass National Forest, southeastern Alaska. Twenty-four fishless headwater streams were sampled monthly, from April to August 1998, across four riparian canopy types: old growth, clearcut, young-growth alder, and young-growth conifer. Young-growth alder sites exported significantly greater count (mean = 9.4 individuals·m–3 water, standard error (SE) = 3.7) and biomass (mean = 3.1 mg dry mass·m–3 water, SE = 1.2) densities of macroinvertebrates than did young-growth conifer sites (mean = 2.7 individuals·m–3 water, SE = 0.4, and mean = 1.0 mg dry mass·m–3 water, SE = 0.2), enough prey to support up to four times more fish biomass if downstream habitat is suitable. We detected no significant differences in macroinvertebrate export between other canopy types or in detritus export among different canopy types. Roughly 70% of the invertebrates were aquatic; the rest were terrestrial or could not be identified. Although we do not recommend clearcutting as a means of generating red alder, maintaining an alder component in previously harvested stands may offset other potentially negative effects of timber harvest (such as sedimentation and loss of coarse woody debris) on downstream, salmonid-bearing food webs.

The characteristics of woody debris and sediment distribution in headwater streams, southeastern Alaska

2001 ◽  
Vol 31 (8) ◽  
pp. 1386-1399 ◽  
Author(s):  
Takashi Gomi ◽  
Roy C Sidle ◽  
Mason D Bryant ◽  
Richard D Woodsmith
Keyword(s):  
Headwater Streams ◽  
Woody Debris ◽  
Mass Movement ◽  
Soil Mass ◽  
Timber Harvesting ◽  
Old Growth ◽  
Sediment Storage ◽  
Sediment Distribution ◽  
Clear Cut ◽  
Recent Landslide

Large woody debris (LWD), fine woody debris (FWD), fine organic debris (FOD), and sediment deposition were measured in 15 steep headwater streams with five management and disturbance regimes. Clear-cut channels logged in 1995 contained large accumulations of logging residue that initially provided sites for sediment storage. Half of the LWD in clear-cut channels was recruited during and immediately after logging. Woody debris from logging activities remains in young growth conifer channels 37 years after logging. Numbers of LWD in clear-cut and young conifer channels were significantly higher than in old-growth channels, although numbers of FWD pieces were not significantly different because of higher recruitment from old-growth stands. Channels that experienced recent (1979 and (or) 1993) and earlier (1961 and (or) 1979) scour and runout of landslides and debris flows contained less LWD and FWD, although large volumes of LWD and FWD were found in deposition zones. The volumes of sediment stored in young alder and recent landslide channels were higher than in the other channels. Because of the recruitment of LWD and FWD from young alder stands, the ratio of sediment stored behind woody debris to total sediment volume was higher in young alder channels compared with recent landslide channels. Numbers of LWD and FWD pieces in all streams were significantly correlated with the volumes of sediment stored behind woody debris. Timber harvesting and soil mass movement influence the recruitment, distribution, and accumulation of woody debris in headwater streams; this modifies sediment storage and transport in headwater channels.

scholarly journals Legacy of Human Impact on Geomorphic Processes in Mountain Headwater Streams in the Perspective of European Cultural Landscapes

Geosciences ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 253
Author(s):  
Tomáš Galia
Keyword(s):  
Human Impact ◽  
Cultural Landscapes ◽  
Headwater Streams ◽  
Timber Harvesting ◽  
Anthropogenic Pressure ◽  
Catchment Scale ◽  
Morphological Response ◽  
Mountain Ranges ◽  
Outer Western Carpathians ◽  
Geomorphic Processes

Mountain headwater streams are still somewhat on the boundary of interest regarding possible human impact on their morphology or geomorphic processes, which may be caused by our perception of mountains as islands of relatively preserved natural conditions. This paper summarizes the past and present human pressure on the headwater streams that drain the highest mountain ranges of the Outer Western Carpathians in Czechia. Anthropogenic pressure began in this region in the 16th century during a colonization of the mountains and continued by timber harvesting, timber floating, and construction of torrent control works until present. Each of these interventions produced a morphological response of the channels in relation to altered sediment or water fluxes at the whole catchment scale or within longitudinal stream profiles. Because it is highly unlikely to reach pre-settlement conditions of the channels, the management effort should be concentrated to achieve realistic restoration targets under the present socioeconomic circumstances by taking into consideration the morphodynamical specifics of mountain headwater streams.

scholarly journals Spatial and Temporal Variability of Macroinvertebrates in Spawning and Non-Spawning Habitats during a Salmon Run in Southeast Alaska

PLoS ONE ◽  
2012 ◽  
Vol 7 (6) ◽  
pp. e39254 ◽  
Author(s):  
Emily Y. Campbell ◽  
Richard W. Merritt ◽  
Kenneth W. Cummins ◽  
M. Eric Benbow
Keyword(s):  
Temporal Variability ◽  
Spatial And Temporal Variability ◽  
Southeast Alaska ◽  
Spawning Habitats

Modeling specific gravity and diameter inside bark of western hemlock and Sitka spruce growing in southeast Alaska

2021 ◽  
Author(s):  
Joseph Dahlen ◽  
David Auty ◽  
Eini C. Lowell
Keyword(s):  
Specific Gravity ◽  
Fixed Effects ◽  
Sitka Spruce ◽  
Western Hemlock ◽  
Fit Indices ◽  
Southeast Alaska ◽  
Important Species ◽  
Explanatory Variables ◽  
Cambial Age ◽  
Young Growth

Western hemlock and Sitka spruce are two commercially important species in Alaska with harvests beginning to focus on naturally regenerated young-growth. We developed within-tree models of ring specific gravity (SG) and diameter inside bark (DIB) for young-growth western hemlock and Sitka spruce. Eight even-aged stands (age < 75 years) in southeast Alaska were felled and disks collected from multiple height levels; 128 trees and 451 disks were collected for western hemlock, and 217 trees and 952 disks were collected for Sitka spruce. Radial strips were prepared and scanned using X-ray densitometry. We fitted non-linear mixed-effects models to the data, with cambial age, height within tree, and dominance class used as explanatory variables. The R2 values (fixed effects only) for the SG models were 0.48 and 0.42 for western hemlock and Sitka spruce, respectively. The corresponding fit indices for the DIB models were 0.86 and 0.85 percent for western hemlock and Sitka spruce, respectively. Tree maps depicting the within tree variation in SG showed more variability in Sitka spruce than in western hemlock. The wood and growth properties of young-growth trees in Alaska will continue to become more important as the U.S. Forest Service transitions away from harvesting old-growth trees.

MICROBES AND NITRATES IN SOILS FROM VIRGIN AND YOUNG-GROWTH FORESTS

1961 ◽  
Vol 7 (5) ◽  
pp. 785-792 ◽  
Author(s):  
W. B. Bollen ◽  
Ernest Wright
Keyword(s):  
Forest Soils ◽  
Ponderosa Pine ◽  
Nitrate Nitrogen ◽  
Nitrate Content ◽  
Soil Incubation ◽  
Red Alder ◽  
Coastal Soils ◽  
Water Holding ◽  
Penicillium Spp ◽  
Young Growth

Penicillium spp. predominated in samples of forest soils except occasionally at depths of more than three inches, when Mucor and Aspergillus spp. sometimes were more abundant. Incubation for 30 days at 28 °C and 50 per cent water-holding capacity frequently increased the percentage of Mucor spp. as well as Penicillium spp. Mucor spp. were consistently more prominent in soils associated with alder than for other coastal soils. Mucor and Aspergillus spp. also appeared often in soil from stands of ponderosa pine growing east of the Cascades.The greatest concentration of nitrogen as NO3− in unincubated soils was found in a young red alder stand. Samples of soil from stands of virgin coastal redwood showed no nitrate nitrogen. Soils from stands of virgin Sitka spruce, however, showed considerable nitrate content, which increased markedly with incubation.With few exceptions, bacteria and actinomycetes were most numerous in F layers of soil. Incubation greatly increased these populations in most soils.

Biomass Regressions for Understory Species in Young-Growth Sitka Spruce–Western Hemlock Forests of Southeast Alaska

2021 ◽  
Vol 95 (1) ◽  
Author(s):  
Annelise Z. Rue-Johns ◽  
Justin S. Crotteau ◽  
David V. D'Amore ◽  
Jeffrey C. Barnard
Keyword(s):  
Sitka Spruce ◽  
Western Hemlock ◽  
Southeast Alaska ◽  
Understory Species ◽  
Young Growth

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
Forested Wetlands ◽  
Timber Harvest ◽  
Large Wood ◽  
Catchment Scale ◽  
Southeast Alaska ◽  
Riparian Management ◽  
Freshwater Habitats ◽  
Study Sites ◽  
Landscape Attributes ◽  
Landscape Influences

<i>Abstract.</i>—Currently, much is known about influences of landscape attributes, including timber harvest practices, on large wood dynamics in streams. Comparatively, much less is known about influences of catchment attributes on Southeast Alaska streams, in part because of a historical lack of consistent catchment-scale data available for the region. As in forested regions elsewhere, large wood is an important resource to stream habitats and fishes in Southeast Alaska. Therefore, the purpose of this study was to characterize catchment-scale influences, including various timber harvest practices, on large wood in Southeast Alaska stream sites. We delineated local catchment boundaries for all stream reaches in the region and summarized landscape influences, including natural and harvest-related attributes in local and network catchments. Relative amounts of variation in four large wood habitat variables explained by natural versus harvest practice-related landscape attributes were evaluated to compare different influences on 28 randomly selected study sites. We used those results to predict variation in large wood variables from our sites through use of both natural and harvest practice-related catchment attributes to identify those that may be most influential to large wood. Natural characteristics, including catchment area, deciduous forests, forested wetlands, and catchment slope, all had significant influences on large wood variables, as did various measures of contemporary and historical timber harvest practices. We found that large wood length was positively related to conventional harvest after 1990, suggesting the potential effectiveness of contemporary logging regulations in protecting large wood characteristics. In our study, both natural and timber harvest practice-related attributes had measureable influences on stream habitat, underscoring the importance of considering catchment-scale attributes, including riparian management schemes, for managing Southeast Alaska streams.

The Ecology and Management of Wood in World Rivers

2003 ◽  
Keyword(s):  
Land Management ◽  
Management Practices ◽  
Riparian Forests ◽  
Floodplain Forests ◽  
Large Wood ◽  
Ecological Processes ◽  
Rivers And Streams ◽  
World Rivers ◽  
Continuous Source

<em>Abstract.</em>—Riparian and floodplain forests are vital components of landscapes. They are transitional zones (ecotones) between river and upland ecosystems where ecological processes occurring in riparian areas and floodplains connect and interact with those of rivers and streams. These forests are the major source of large wood for streams and rivers. Extensive loss of riparian and floodplain forests around the globe is evident from the dramatically reduced supply of large wood in rivers. Clearly, it is necessary to conserve and restore riparian forests to sustain a supply of wood for rivers. This chapter discusses river and land management practices that are designed to provide a continuous source of large wood for rivers and retain wood once it has entered the channel or floodplain. These management practices include conservation of intact riparian and floodplain forests, restoration of ecological processes necessary to sustain riparian forests in the long term, and management of riparian forests specifically to accelerate recruitment of large wood to rivers and streams.

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