Small-mammal response to group-selection silvicultural systems in Engelmann spruce – subalpine fir forests 14 years postharvest

2009 ◽  
Vol 39 (9) ◽  
pp. 1698-1708 ◽  
Author(s):  
Douglas B. Ransome ◽  
Pontus M.F. Lindgren ◽  
Michaela J. Waterhouse ◽  
Harold M. Armleder ◽  
Thomas P. Sullivan

Concerns about the impacts of clear-cut harvesting on ecosystem components in subalpine forests have generated a variety of alternative silvicultural systems in high-elevation forests in western North America. We examined responses of forest-floor small mammals, 14 years posttreatment, in four replicate units, uncut forest, a 1.0 ha group-selection cut, a large (>30 ha) clearcut, and the edge between the group-selection cut and uncut forest, in the Engelmann Spruce ( Picea engelmannii Parry ex Engelm.) – Subalpine Fir ( Abies lasiocarpa (Hook.) Nutt.) biogeoclimatic zone in south-central British Columbia, Canada. Populations of small mammals were livetrapped during five sessions from June to September 2006. The mean abundance of southern red-backed voles ( Myodes gapperi Vigors) was significantly lower on large clearcuts than in uncut old-growth forests, with intermediate numbers in 1 ha cuts. The opposite trend was found for dusky shrews ( Sorex monticolus Merriam), while there was no significant difference in mean abundance of deer mice ( Peromyscus maniculatus Wagner) among treatments. Trappability, proportion of adult females breeding, and rate of survival of red-backed voles and deer mice were similar among treatments. Our results suggest that group-selection silviculture conducted in subalpine forests may have fewer negative impacts on the small-mammal community than large clearcuts.

2014 ◽  
Vol 27 (3) ◽  
pp. 233-256 ◽  
Author(s):  
Andrea C. Voit ◽  
Richard J. Hebda ◽  
Julien M.J. Racca ◽  
Reinhard Pienitz ◽  
Ian R. Walker ◽  
...  

Diatom analyses of sediments from a high elevation lake situated in an Engelmann Spruce - Subalpine Fir (ESSF) forest of south-central British Columbia, Canada, reveal long-term climate and water chemistry change. During the transition from the late-glacial / Pleistocene to the xerothermic early Holocene, small, benthic Fragilaria diatoms species that grew under low light conditions in Sicamous Creek Lake gave way to planktonic Cyclotella species that require open-water conditions. Warm temperatures in the mesothermic Holocene are indicated by smaller Cyclotella species and large, benthic pennate diatoms. Diatom communities reflected Neoglacial cooling in the late Holocene, with abundant Nitzschia fonticola and Achnanthes minutissima. Small, benthic Fragilaria regained abundance, suggesting cooling and conditions similar to the late-glacial interval. Diatom community composition responded to the deposition of the Mt. Mazama and Mt. St. Helens tephras, though the Mazama eruption caused greater change in relative abundance of various taxa within the assemblage. Correspondence analysis shows distinct communities have occurred since the initiation of sedimentation, likely due to climate controlled landscape and vegetation changes; diatom-inferred pH values using various models and training sets show limited acidification change occurred through the lake’s history.


1999 ◽  
Vol 75 (3) ◽  
pp. 467-472 ◽  
Author(s):  
Alan Vyse

The Sicamous Creek Project was established as part of the British Columbia Provincial Silvicultural Systems program in 1990 to investigate the effects of clearcutting and other practices on a high elevation forested ecosystem. The objective is to provide the forestry community with information on the ecology of high elevation forests in the Southern Interior, and the probable responses to a wide range of disturbance. After a period of planning by a team of scientists and foresters from several agencies, a site in subalpine fir-Engelmann spruce forest at 1530 m to 1830 m elevation near the town of Sicamous in the south central interior of British Columbia was logged in the winter of 1994–95. A range of treatments was created by logging one third of the forest in 30 ha experimental units using a range of opening sizes (individual tree selection, 1/10 ha, 1 ha, and 10 ha) and a no-logging control. Within these experimental units, smaller areas (0.08 ha) have been treated to create a range of soil disturbance conditions (no disturbance, burning, complete organic soil removal, mounding). A wide range of studies has been conducted on the site by a team of scientists before and after treatment and those studies are continuing. The project is long-term, (at least 30 years), the main treatments are sufficiently large to have operational significance, and the supported studies are intended to be interdisciplinary in scientific method and scope. Support for the project is strong within the operational forestry community because information on logging costs, safety issues and snags, windthrow, bark beetle management, wildlife habitat and small streams has already been made available to them. Studies of stand structure and wildlife habitat suggest that in future much greater emphasis should be placed on the silviculture of fir than spruce. Key words: silviculture systems, clearcutting, opening size, Engelmann spruce, subalpine fir, long term research, interdisciplinary research


2006 ◽  
Vol 82 (1) ◽  
pp. 84-94 ◽  
Author(s):  
C C Lajzerowicz ◽  
A. Vyse ◽  
M. Jull ◽  
T. Newsome

We compared survival and growth of planted seedlings of Engelmann spruce and subalpine fir across a range of harvest opening sizes (> 10 ha, 1 ha, 0.2 ha, 0.1 ha, 0.03 ha and individual tree selection) from three silvicultural systems trials in high-elevation spruce – subalpine fir forests in south-central British Columbia. Climatic patterns and growing season air and soil temperatures were similar across sites. Seedling survival decreased with opening size. Local site climates, influenced by aspect and moisture and air drainage, were more influential than elevation. Seedling growth was best in large openings and similar in opening sizes from 1 ha to 0.1 ha. Smaller openings created by group selection and individual tree selection methods were not favourable for successful planting at elevations close to timberline. The two species had similar absolute and relative growth rates but spruce responded more strongly to better growing environments. Key words: planted seedlings, Engelmann spruce, Picea engelmannii Parry ex Engelm., subalpine fir, Abies lasiocarpa (Hook.) Nutt., opening size, elevation effects, silvicultural systems, British Columbia, mountain forests


2003 ◽  
Vol 33 (5) ◽  
pp. 847-853 ◽  
Author(s):  
Sylvia E Welke ◽  
Graeme D Hope ◽  
Gary A Hunt

The effect of timber harvesting on the biomass, nutrient standing crop, and decomposition of fine roots (<2 mm) was studied in a high elevation, Engelmann spruce (Picea engelmannii Parry ex Engelm.) – subalpine fir (Abies lasiocarpa (Hook.) Nutt.) forest. Root dynamics were compared in openings of different sizes. The sequential core method was used to collect fine root samples over 4 years. Differences in fine root biomass between opening sizes were most significant for the active fine root portion and were most pronounced in the fall compared with the spring. Active fine root biomass was significantly lower in the 10-ha clearcuts (164 kg/ha) compared with control plots (275 kg/ha). Furthermore, active fine root biomass was often lower in the 1.0-ha opening than in the 0.1-ha and control plots. A similar trend was established for inactive fine root biomass, although this was not consistent over sampling years. Nutrient concentrations of K, but no other elements, were higher in control plots. Nutrient standing crops, however, followed trends observed in fine root biomass. In the 10-ha clearcuts, the largest changes in fine root biomass occurred at the edge of the opening. The findings suggest that small (<10 ha) cutblocks may maintain greater fine root longevity.


2011 ◽  
Vol 6 (3) ◽  
pp. 446-456 ◽  
Author(s):  
Marija Kataržytė ◽  
Ernestas Kutorga

AbstractThe diets of small mammals in different hemiboreal spruce-dominated, oak-dominated and mixed forests in western part of Lithuania were studied by examination of fungal spores in fresh fecal pellets of caught animals. In the diets of mice (Apodemus spp.), bank voles (Myodes glareolus), and common and pygmy shrews (Sorex araneus and S. minutus), 22 different fungal taxa were identified, 15 of which were hypogeous fungi. The sporocarp abundance and the spores in fecal samples of Elaphomyces fungi prevailed in study area during this investigation. Although most of the captured individuals consumed fungi, the consumption varied among small mammal species. The data show that the fungi were more frequent and taxonomically diverse in Myodes glareolus than in Apodemus spp. diets. The study provided evidence that the fungal component in the diets of insectivorous Sorex species is more diverse than previously known. The availability of sporocarps and the fungal component in the diets of small mammals showed seasonal effects. Annual hypogeous and epigeous sporocarp abundances did not vary significantly across forest types. The significant difference in mycophagy was observed across all forest cover types, with the greatest fungal diversity in fecal samples collected in mixed coniferous-deciduous tree stands.


2015 ◽  
Vol 97 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Petra Villette ◽  
Charles J. Krebs ◽  
Thomas S. Jung ◽  
Rudy Boonstra

Abstract Estimating population densities of small mammals (&lt; 100g) has typically been carried out by intensive livetrapping, but this technique may be stressful to animals and the effort required is considerable. Here, we used camera traps to detect small mammal presence and assessed if this provided a feasible alternative to livetrapping for density estimation. During 2010–2012, we used camera trapping in conjunction with mark–recapture livetrapping to estimate the density of northern red-backed voles ( Myodes rutilus ) and deer mice ( Peromyscus maniculatus ) in the boreal forest of Yukon, Canada. Densities for these 2 species ranged from 0.29 to 9.21 animals/ha and 0 to 5.90 animals/ha, respectively, over the course of this investigation. We determined if hit window—the length of time used to group consecutive videos together as single detections or “hits”—has an effect on the correlation between hit rate and population density. The relationship between hit rate and density was sensitive to hit window duration for Myodes with R2 values ranging from 0.45 to 0.59, with a 90-min hit window generating the highest value. This relationship was not sensitive to hit window duration for Peromyscus , with R2 values for the tested hit windows ranging from 0.81 to 0.84. Our results indicate that camera trapping may be a robust method for estimating density of small rodents in the boreal forest when the appropriate hit window duration is selected and that camera traps may be a useful tool for the study of small mammals in boreal forest habitat.


2003 ◽  
Vol 33 (11) ◽  
pp. 2210-2220 ◽  
Author(s):  
Cindy E Prescott ◽  
Graeme D Hope ◽  
Leandra L Blevins

Possible mitigation of nitrate losses associated with clearcuts through harvesting smaller gaps was tested in a high-elevation forest of Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.). We measured concentrations of ammonium and nitrate after 6-week buried bag incubations of forest floor and mineral soil samples in replicated plots of uncut forest and gaps of 10, 1.0, and 0.1 ha and single-tree removal for 7 years after harvest. Nitrate concentrations in forest floor and mineral soil were elevated 3–7 years after harvesting in gaps of 0.1 ha and larger. Removal of the same proportion of trees as single trees did not result in increased nitrate concentrations, suggesting that nitrate losses could be reduced by harvesting single trees rather than creating gaps. Greater N availability was not associated with faster rates of decomposition of litter and forest floor, which were similar in gaps of all sizes (0–10 ha). Reciprocal transplant of forest floor and soil from the 10-ha gaps and the uncut forests indicated that changes in the nature of the forest floor or soil following harvest had a greater influence on nitrate concentrations than the changes in environmental conditions in the gaps.


1996 ◽  
Vol 26 (11) ◽  
pp. 2023-2034 ◽  
Author(s):  
J. Bruce Runciman ◽  
Thomas P. Sullivan

This study was designed to test the hypothesis that conifer release treatments would simplify habitat structure and reduce small mammal populations in forest plantations. A secondary objective was to examine some important demographic characteristics, for selected small mammal species, that may be affected by changes in habitat. We examined the effects of manual cutting and cut-stump applications of glyphosate herbicide on vegetation, woody debris, and small mammal populations from 1991 to 1994 in young mixed-conifer plantations of south central British Columbia, Canada. The experimental design consisted of 9 separate and independent plantations: 3 controls, 3 manual treatments, and 3 cut-stump treatments. Total volumes of herbs, shrubs, coniferous trees, and woody debris were not affected by manual or cut-stump treatments for conifer release. Both treatments reduced total volumes of deciduous trees in the first posttreatment year. However, deciduous tree volumes on manual treatments had largely returned to pretreatment levels by the second posttreatment year. There were no significant (P > 0.05) effects of manual or cut-stump treatments on the population size of deer mice (Peromyscusmaniculatus Wagner), yellow-pine chipmunks (Tamiasamoenus J.A. Allen), southern red-backed voles (Clethrionomysgapped Vigors), or long-tailed voles (Microtuslongicaudus Merriam). The response of meadow voles (Microtuspennsylvanicus Ord) was variable. Sex ratios, body weights, reproduction, recruitment, and survival of deer mice remained similar on treatment and control plantations throughout this study. Changes in habitat structure up to 2 years posttreatment did not appear to exceed the tolerance of small mammal populations for early successional change.


2006 ◽  
Vol 21 (4) ◽  
pp. 178-184
Author(s):  
Gregory M. Filip ◽  
Craig L. Schmitt ◽  
Kristen L. Chadwick

Abstract High-elevation true fir stands on federal lands have a long history of selective harvesting. In 1989 a high frequency (89%) of Heterobasidion annosum, the cause of annosus root disease, was found in residual true fir stumps (mean, 20-in. diameter) cut 5–9 years earlier in northeast Oregon. In 2004, H. annosum was found at the stump surface of 29% of the natural conifer regeneration (mean, 18 years) within 20 ft of infected residual stumps. A total of 16 of 122 (13%) live saplings had H. annosum–caused stain or decay. Only 3% of 126 sample trees, however, were dead and infected by H. annosum. Infection was confirmed in 62% of decayed trees, 33% of stained trees, and 22% of trees with no visible stain or decay at the stump surface. Only 3 of 122 living saplings showed typical root disease crown symptoms (chlorosis), but only one of these had H. annosum. Only 1 of 16 live saplings with H. annosum–caused stain or decay was chlorotic. Incidence of infection was 44% in Engelmann spruce (7 of 16 trees), 31% in Douglas-fir (5 of 16 trees), 31% in subalpine fir (4 of 13 trees), and 27% in grand fir (21 of 77 trees). The S-type of H. annosum was confirmed in a sampled grand fir. There were no significant differences between H. annosum–infected and apparently healthy trees regarding live crown ratio and distance from infected residual stumps. Infected trees, however, were significantly (P = 0.025) larger in diameter than apparently healthy trees. The dynamics of H. annosum infection in spruce and Douglas-fir in northeast Oregon are discussed as well as treating true fir stumps with boron-containing products to prevent stump infection by H. annosum. West. J. Appl. For. 21(4):178–184.


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