Snow avalanche penetration into mature forest from timber-harvested terrain

2012 ◽  
Vol 49 (4) ◽  
pp. 477-484 ◽  
Author(s):  
G. Anderson ◽  
D. McClung
Keyword(s):  
British Columbia ◽  
Forest Cover ◽  
Significant Risk ◽  
Lateral Spread ◽  
Snow Avalanches ◽  
Clear Cut ◽  
Mature Forest ◽  
Columbia Mountains ◽  
Vegetation Characteristics ◽  
Terrain Characteristics

Clear-cut logging in British Columbia, Canada, is creating new avalanche start zones from which snow avalanches sufficient in size to penetrate and destroy mature forest cover can initiate. In addition to creating new start zones, the presence of these logging cut blocks can augment the destructive potential of previously existing avalanche paths. Forest-penetrating avalanches can pose a significant risk to down-slope structures and resources. This study is the first to develop and utilize a database containing information on penetration distances and lateral spread from avalanches that have penetrated forest cover. The study area for this research spans the Southern Coast and Columbia Mountains of British Columbia, Canada. Analysis focuses on terrain characteristics related to forest penetration and the resultant destruction of mature standing forest. Physical terrain and vegetation characteristics in the avalanche starting zone, track, and runout zone of 45 forest-penetrating avalanches are described, measured, and parameterized. The results provide tools to assess and evaluate potential forest-penetrating avalanche terrain, and runout models for avalanches in forested terrain.

scholarly journals Characteristics of terrain, snow supply and forest cover for avalanche initiation caused by logging

2001 ◽  
Vol 32 ◽  
pp. 223-229 ◽  
Author(s):  
D. M. McClung
Keyword(s):  
British Columbia ◽  
Forest Cover ◽  
Ground Surface ◽  
Vegetation Density ◽  
Coast Mountains ◽  
Clear Cut ◽  
Vegetation Height ◽  
Data Framework ◽  
Columbia Mountains ◽  
Ground Surface Roughness

AbstractThis paper contains statistical analyses of parameters to characterize starting zones of destructive avalanches which have resulted from clear-cut logging in British Columbia, Canada. Data from 76 avalanche sites in the Coast Mountains (western British Columbia) and the Columbia Mountains (eastern British Columbia) are analyzed. The parameters include a selection which characterize snow supply (related to potential avalanche frequency), avalanche magnitude and those which are known to affect avalanche formation including terrain features, vegetation density, vegetation height and ground surface roughness. The results provide the data framework for possibly preventing future disasters by altering logging plans.

Effects of elevation and forest cover on winter birds in mature forest ecosystems of southern British Columbia

2004 ◽  
Vol 82 (11) ◽  
pp. 1720-1730 ◽  
Author(s):  
Jim R Herbers ◽  
Robert Serrouya ◽  
Katherine A Maxcy
Keyword(s):  
British Columbia ◽  
Forest Cover ◽  
Forest Ecosystems ◽  
Lodgepole Pine ◽  
Previous History ◽  
Bird Species ◽  
High Elevation ◽  
Mature Forest ◽  
Bird Density ◽  
Coarse Filter

Winter diversity, distribution, and density of nonmigratory birds were examined in six mature forest ecosystems from two study areas in southern British Columbia. Forest age ranged from 91 to 150 years and the ecosystems ranged from 500 to 2100 m above sea level. Sampled forest stands had no previous history of logging and were a minimum 30 ha in size. The main objectives of this study were to measure nonmigratory birds in relation to elevation and to percentage of stand-level lodgepole pine composition. Twenty-one nonmigratory bird species totaling 2747 observations were detected at 775 point-count stations in 107 stands using 10-min unlimited-distance point counts. Pine siskins (Carduelis pinus (Wilson, 1810)), red-breasted nuthatches (Sitta canadensis L., 1766), and red crossbills (Loxia curvirostra L., 1758) were the three most commonly detected species. Mature forests at low elevation had between 1.7 and 3.5 times more species and between 2.0 and 4.7 times more birds than forests at high elevation. In addition, species richness and bird density declined with increasing stand-level composition of lodgepole pine. We suggest that low-elevation ecosystems be given high priority in coarse-filter management of winter bird habitat.

Supplementary Checks on the Scales of Pink Salmon (Oncorhynchus gorbuscha) and Chum Salmon (O. keta)

1965 ◽  
Vol 22 (6) ◽  
pp. 1477-1489 ◽  
Author(s):  
H. T. Bilton ◽  
W. E. Ricker
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Commercial Fisheries ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Clear Cut ◽  
Second Year Of Life ◽  
Second Year ◽  
Similar Incidence

Among 159 central British Columbia pink salmon that had been marked by removal of two fins as fry and had been recovered in commercial fisheries after one winter in the sea, the scales of about one-third showed a supplementary or "false" check near the centre of the scale, in addition to the single clear-cut annulus. This evidence from fish of known age confirms the prevailing opinion that such extra checks do not represent annuli, hence that the fish bearing them are in their second year of life rather than their third. Unmarked pink salmon from the same area, and some from southern British Columbia, had a generally similar incidence of supplementary checks. In both marked and unmarked fish the supplementary checks varied in distinctness from faint to quite clear. In a sample of scales of 14 double-fin marked chum salmon which were known to be in their 4th year, all fish had the expected 3 annuli, and 12 fish had a supplementary check inside the first annulus.

scholarly journals Natural Regeneration of the Tree Stand in the Bilberry Spruce Forest—Clear-Cutting Ecotone Complex in the First Post-Logging Decade

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1542
Author(s):  
Nadezhda V. Genikova ◽  
Viktor N. Mamontov ◽  
Alexander M. Kryshen ◽  
Vladimir A. Kharitonov ◽  
Sergey A. Moshnikov ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Forest Canopy ◽  
Forest Cover ◽  
Forest Type ◽  
Ground Cover ◽  
Woody Species ◽  
Forest Edge ◽  
Tree Canopy ◽  
Clear Cut ◽  
Clear Cutting

Bilberry spruce forests are the most widespread forest type in the European boreal zone. Limiting the clear-cuttings size leads to fragmentation of forest cover and the appearance of large areas of ecotone complexes, composed of forest (F), a transition from forest to the cut-over site under tree canopy (FE), a transition from forest to the cut-over site beyond tree canopy (CE), and the actual clear-cut site (C). Natural regeneration of woody species (spruce, birch, rowan) in the bilberry spruce stand—clear-cut ecotone complex was studied during the first decade after logging. The effects produced by the time since cutting, forest edge aspect, and the ground cover on the emergence and growth of trees and shrubs under forest canopy and openly in the clear-cut were investigated. Estimating the amount and size of different species in the regeneration showed FE and CE width to be 8 m—roughly half the height of first-story trees. Typical forest conditions (F) feature a relatively small amount of regenerating spruce and birch. The most favorable conditions for natural regeneration of spruce in the clear-cut—mature bilberry spruce stand ecotone are at the forest edge in areas of transition both towards the forest and towards the clear-cut (FE and CE). Clear-cut areas farther from the forest edge (C) offer an advantage to regenerating birch, which grows densely and actively in this area.

scholarly journals Managing Woodland Caribou in West-Central British Columbia

Rangifer ◽  
1996 ◽  
Vol 16 (4) ◽  
pp. 119 ◽  
Author(s):  
Deborah B. Cichowski
Keyword(s):  
British Columbia ◽  
Management Strategy ◽  
Forest Cover ◽  
Planning Process ◽  
Timber Harvesting ◽  
Range Management ◽  
Management Options ◽  
Winter Habitat ◽  
Specific Level ◽  
Winter Range

Initial long term planning for logging on the Tweedsmuir-Entiako caribou winter range began in the early 1980s. Because little information was available on which to base winter range management, the British Columbia Fish and Wildlife Branch began studies on radio-collared caribou in 1983, and an intensive study on caribou winter habitat requirements was conducted from 1985 to 1988. Terrestrial lichens were identified as the primary winter food source for the caribou, and in 1987, caribou winter range ecosystem maps, which emphasized abundance of terrestrial lichens, were produced. The ecosystem maps and information from the caribou study, including potential direct and indirect effects of timber harvesting on the caribou population, were used to develop a management strategy for the winter range. The management strategy comprised two levels of management: a landscape level (Caribou Management Zones); and a site-specific level (caribou habitat/timber values). Timber information associated with BC Ministry of Forests forest cover maps was integrated using a Geographic Information System. Six winter range management options were proposed ranging from harvesting low value caribou habitats only throughout the winter range to total protection of the entire winter range. Impacts of those options on both the caribou population and on the timber supply were evaluated. The options were reviewed through a public planning process, the Entiako Local Resource Use Plan, and recommendations from that process were forwarded to the British Columbia Protected Areas Strategy.

Colonization and decomposition of salal (Gaultheria shallon) leaf litter by saprobic fungi in successional forests on coastal British Columbia

2008 ◽  
Vol 54 (6) ◽  
pp. 427-434 ◽  
Author(s):  
Takashi Osono ◽  
Susumu Iwamoto ◽  
John A. Trofymow
Keyword(s):  
British Columbia ◽  
Leaf Area ◽  
Leaf Litter ◽  
Fungal Colonization ◽  
Gaultheria Shallon ◽  
Food Web Structure ◽  
Old Growth ◽  
Saprobic Fungi ◽  
Clear Cut ◽  
Recalcitrant Compounds

The colonization of leaf litter by saprobic fungi was studied in old-growth and post-harvest successional Douglas-fir forests on southeast Vancouver Island, British Columbia. This study focused on leaf litter of salal ( Gaultheria shallon Pursh.), a dominant understory shrub in all stands. Salal litter is characterized by the occurrence of bleached portions attributable to fungal colonization of the litter and to the variable decomposition of recalcitrant compounds, such as lignin. Analyses of proximate chemical fractions, fungal assemblages on the bleached leaf area, and pure culture decomposition assays indicated that Marasmius sp. and Coccomyces sp. were responsible for rapid decomposition and bleaching of salal leaf litter. The bleached area accounted for 17%–22% of total area of salal leaf litter collected in immature (40–60 years old), mature (85–105 years old), and old-growth (more than 290 years old) stands, but for only 2% in regeneration (5–15 years old) stands. The reduction of bleached leaf area occupied by Marasmius sp. and Coccomyces sp. in regeneration stands could be due to the changes in microenvironmental conditions on the forest floor, in litter quality, or in food-web structure in soils. The decrease of fungi able to decay recalcitrant compounds may lead to a reduction of salal decomposition rates in clear-cut sites that would persist until canopy closure occurs.

scholarly journals Habitat associations of American badgers in southeastern British Columbia

2002 ◽  
Vol 80 (7) ◽  
pp. 1228-1239 ◽  
Author(s):  
Clayton D Apps ◽  
Nancy J Newhouse ◽  
Trevor A Kinley
Keyword(s):  
British Columbia ◽  
Forest Cover ◽  
Human Impacts ◽  
Sandy Loam ◽  
Spatial Scales ◽  
Parent Material ◽  
Habitat Associations ◽  
Vegetation Productivity ◽  
Fine Sandy Loam ◽  
Taxidea Taxus

American badgers (Taxidea taxus) are endangered in British Columbia due to habitat loss and human-caused mortality. To better understand human impacts and to promote conservation planning, we described badger habitat relationships. At two spatial scales, we analyzed selection by 12 radio-implanted resident badgers for soil composition, forest overstory, land cover, vegetation productivity, terrain, and human influence. At a broad (23.8 km2) landscape scale, soil parent-material associations were positive with glaciolacustrine and glaciofluvial and negative with colluvial. Soil-order associations were positive with brunisols and regosols and negative with podzols and luvisols. Association with fine sandy-loam texture was positive. Associations were negative with forested habitats and positive with open range, agricultural habitats, and linear disturbances. Associations were negative with elevation, slope, terrain ruggedness, and both vegetation productivity and moisture. At a fine (14.5 ha) scale, associations were positive with glaciofluvial, fine sandy-loam textured, and well-drained soils. Associations were negative with colluvial soils, forest cover, vegetation moisture, elevation, and ruggedness. Associations with open range and southern aspects were positive. The linear combination of a subset of variables could explain and predict habitat selection. At this range extent, natural conditions may restrict badger occurrence, increasing badger sensitivity to human factors that influence habitat quality and mortality.

Stream habitat and rainbow trout (Oncorhynchus mykiss) physiological stress responses to streamside clear-cut logging in British Columbia

2005 ◽  
Vol 35 (3) ◽  
pp. 541-556 ◽  
Author(s):  
Eric Mellina ◽  
Scott G Hinch ◽  
Edward M Donaldson ◽  
Greg Pearson
Keyword(s):  
British Columbia ◽  
Rainbow Trout ◽  
Chronic Stress ◽  
Stress Responses ◽  
Plasma Cortisol ◽  
Acute Stress ◽  
Physiological Stress ◽  
Stream Habitat ◽  
Clear Cut ◽  
Rainbow Trout Oncorhynchus Mykiss

The impacts associated with streamside clear-cut logging (e.g., increased temperatures and sedimentation, loss of habitat complexity) are potentially stressful to stream-dwelling fish. We examined stream habitat and rainbow trout physiological stress responses to clear-cut logging in north-central British Columbia using 15 streams divided into three categories: old growth (reference), recently logged (clear-cut to both banks 1–9 years prior to the study), and second growth (clear-cut 25–28 years prior to the study). We used plasma cortisol and chloride concentrations as indicators of acute stress, and interrenal nuclear diameters, impairment of the plasma cortisol response, and trout condition and length-at-age estimates as indicators of chronic stress. No statistically significant acute or chronic stress responses to streamside logging were found, despite increases in summertime stream temperatures (daily maxima and diurnal fluctuations) and a reduction in the average overall availability of pool habitat. Our observed stress responses were approximately an order of magnitude lower than what has previously been reported in the literature for a variety of different stressors, and trout interrenal nuclear diameters responses to the onset of winter were approximately five times greater than those to logging. The overall consistency of our results suggests that the impacts of streamside clear-cut logging are not acutely or chronically stressful to rainbow trout in our study area.

The effects of forest harvesting and best management practices on streamflow and suspended sediment concentrations during snowmelt in headwater streams in sub-boreal forests of British Columbia, Canada

2003 ◽  
Vol 33 (8) ◽  
pp. 1397-1407 ◽  
Author(s):  
J S Macdonald ◽  
P G Beaudry ◽  
E A MacIsaac ◽  
H E Herunter
Keyword(s):  
British Columbia ◽  
Suspended Sediment ◽  
Best Management Practices ◽  
Boreal Forests ◽  
Management Practices ◽  
Complete Removal ◽  
Sediment Concentration ◽  
Forest Harvesting ◽  
Clear Cut ◽  
Best Management

This paper examines suspended sediment concentration and stream discharge during freshet in three small sub-boreal forest streams (<1.5 m in width) in the central interior of British Columbia for 1 year prior to (1996) and for 5 years following forest harvesting (1997–2001). Harvesting prescriptions in a 20-m strip beside one stream required complete removal of merchantable timber (>15 cm diameter at breast height (DBH) for pine and >20 cm for spruce), while all stems <30 cm DBH were retained beside a second stream. A third stream remained unharvested as a control. The two riparian treatments were prescribed to test the efficacy of current British Columbia legislation that allows for varying amounts of riparian retention as best management practices for the management of windthrow. Both treated watersheds were clear-cut harvested (approximately 55% removal) in January 1997, and in the following year, temporary access roads were deactivated, including two stream crossings in the low-retention watershed. An increase in peak snowmelt and total freshet discharge was first noted in the second spring following harvest in both treatments and remained above predicted in all subsequent years. Suspended sediment also increased during freshet following harvest but returned to levels at or below preharvest predictions within 3 years or less in the high-retention watershed.

Scale-Dependent Habitat Selection by Mountain Caribou, Columbia Mountains, British Columbia

2001 ◽  
Vol 65 (1) ◽  
pp. 65 ◽  
Author(s):  
Clayton D. Apps ◽  
Bruce N. McLellan ◽  
Trevor A. Kinley ◽  
John P. Flaa
Keyword(s):  
British Columbia ◽  
Habitat Selection ◽  
Columbia Mountains
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