scholarly journals Natural and Advance Regeneration of Engelmann Spruce and Subalpine Fir Compared 21 Years After Site Treatment

1980 ◽  
Vol 56 (2) ◽  
pp. 55-57 ◽  
Author(s):  
L. J. Herring ◽  
R. G. McMinn
Keyword(s):  
Natural Regeneration ◽  
Mineral Soil ◽  
Poor Performance ◽  
Abies Lasiocarpa ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Advance Regeneration ◽  
Residual Tree ◽  
Mean Current ◽  
Picea Engelmanni

The mean height of Engelmann spruce (Picea engelmanni Parry) advance growth 21 years after release by overstorey harvesting and residual tree felling, was eight times that of natural regeneration established following brush blade scarification. Subalpine fir (Abies lasiocarpa (Hook.) Nutt.) advance growth was nine times taller than natural regeneration established on scarified soil. Mean current annual height increment of Engelmann spruce and subalpine fir advance growth was 39 and 34 cm, respectively, compared with only 7 cm for natural regeneration on scarified soil. The performance gap does not appear to be narrowing. The poor performance of natural regeneration on mineral soil exposed by blade scarification is attributed to removal of organic and top mineral soil horizons beyond the immediate reach of seedlings. These soil layers remained available to the advance growth. Consideration should be given to preserving advance growth when scarification may be inappropriate.

Effect of gap size on litter decomposition and soil nitrate concentrations in a high-elevation spruce–fir forest

2003 ◽  
Vol 33 (11) ◽  
pp. 2210-2220 ◽  
Author(s):  
Cindy E Prescott ◽  
Graeme D Hope ◽  
Leandra L Blevins
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
High Elevation ◽  
N Availability ◽  
Abies Lasiocarpa ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Nitrate Losses ◽  
Nitrate Concentrations ◽  
High Elevation Forest

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.

scholarly journals GROWTH AND SURVIVAL OF ENGELMANN SPRUCE AND ALPINE FIR ON SEED SPOTS AT BOLEAN LAKE, B.C., 1954-59

1960 ◽  
Vol 36 (1) ◽  
pp. 46-49 ◽  
Author(s):  
J. Harry G. Smith ◽  
M. Bruce Clark
Keyword(s):  
Mineral Soil ◽  
First Year ◽  
Abies Lasiocarpa ◽  
Poor Survival ◽  
Growth And Survival ◽  
Engelmann Spruce ◽  
Survival And Growth ◽  
Picea Engelmanni ◽  
Shade Part ◽  
Site Types

Seed spots established in the spring of 1953 were remeasured in August 1959. Variables included Engelmann spruce (Picea Engelmanni Parry) and alpine fir (Abies lasiocarpa (Hook.) Nutt.); two site types—wet (VO) and dry (VM); three degrees of light—full shade, part shade, and full sun; and five seedbeds—mineral soil, burn, moss, litter, and rotted wood. The observed data on survival and growth are further evidence of the need to provide adequately disturbed seedbeds to ensure reproduction of Engelmann spruce and alpine fir. The poor survival, even with first-year screening, and slow juvenile growth of these species suggest that planting may have advantages over direct seeding.

Factors affecting natural regeneration of Abies lasiocarpa and Picea engelmannii in a subalpine silvicultural systems trial

1999 ◽  
Vol 29 (12) ◽  
pp. 1847-1855 ◽  
Author(s):  
Andrea M Eastham ◽  
Michael J Jull
Keyword(s):  
Natural Regeneration ◽  
Mineral Soil ◽  
Limiting Factors ◽  
Picea Engelmannii ◽  
Limiting Factor ◽  
Abies Lasiocarpa ◽  
Factors Affecting ◽  
Subalpine Fir ◽  
Small Patch ◽  
Seedbed Preparation

An experiment was established in 1991-1992 in northern British Columbia to investigate factors influencing natural regeneration rates of Engelmann spruce (Picea engelmannii Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in three stand structures created by harvesting. Harvest treatments were a 32-ha clearcut, 0.2-ha patch cuts, and single-tree selection. Cone crop periodicity was independent of harvesting system. Natural seedfall was higher in the selection treatment and small patch cut than the clearcut treatment every year. Five years after harvest, the selection and patch cut treatments had 7 times as many spruce germinants and 10 times as many subalpine fir germinants as the clearcut treatment. Seed availability appears to be the primary limiting factor for establishment of both subalpine fir and spruce in the clearcut treatment. For spruce establishment in the selection and small patch cut treatments, availability of both seed and mineral soil seedbeds were limiting factors, while for subalpine fir, germinant establishment appears primarily limited by availability of disturbed forest floor seedbeds. Foresters could increase opportunities for natural regeneration in these subalpine forests by (i) modifying harvest patterns to enhance conifer seed distribution over harvested areas and (ii) applying seedbed preparation treatments prior to anticipated heavy seedfalls.

Segregation of allozyme loci in megagametophytes of Engelmann spruce and subalpine fir

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 103-107 ◽  
Author(s):  
Kathleen L. Shea
Keyword(s):  
Natural Populations ◽  
Segregation Ratio ◽  
Colorado Front Range ◽  
Abies Lasiocarpa ◽  
Front Range ◽  
Subalpine Fir ◽  
Polymorphic Loci ◽  
Engelmann Spruce ◽  
Low Levels ◽  
Allozyme Loci

Segregation ratios and linkage of 10 allozyme loci were examined in haploid megagametophytes obtained from natural populations of Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) in the Colorado Front Range. For data pooled over trees, the 1:1 segregation ratio expected at Mendelian loci was obtained for five polymorphic loci in 32 Engelmann spruce trees and for seven polymorphic loci in 40 subalpine fir trees. The Gdh and Idh loci in spruce were very tightly linked: no recombinants were detected among 60 megagametophytes of trees heterozygous for both loci. In fir only the Aco and Pgm-1 loci were linked, with an estimated recombination rate of 0.317 ± 0.073. The low levels of among-tree heterogeneity and of segregation distortion found in these populations suggest that reliable estimates of both genetic variation and outcrossing rates can be obtained using allozyme data from these wind-pollinated species.Key words: segregation, linkage, allozymes, Engelmann spruce, subalpine fir.

Inonotus tomentosus and the dynamics of unmanaged and partial-cut wet sub-boreal spruce–fir forests

2007 ◽  
Vol 37 (12) ◽  
pp. 2663-2676 ◽  
Author(s):  
J. E. (Ted) Newbery ◽  
Kathy J. Lewis ◽  
Michael B. Walters
Keyword(s):  
Picea Glauca ◽  
Dead Wood ◽  
Basal Area ◽  
Tree Density ◽  
Small Scale ◽  
Abies Lasiocarpa ◽  
Partial Cutting ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Live Tree

For wet sub-boreal spruce–fir forests (white spruce ( Picea glauca (Moench) Voss) × Engelmann spruce ( Picea engelmannii Parry ex Engelm.) – subalpine fir ( Abies lasiocarpa (Hook.) Nutt.)) in east-central British Columbia, we asked (i) do compositional and structural dynamics differ for unmanaged (UN) and partial-cut (PC) (50% removal 45 years before measurement) forests and (ii) how does Inonotus tomentosus Fr. (Teng) affect these dynamics? Inonotus tomentosus infected stands had 17% less spruce basal area (P = 0.059) than uninfected stands, but PC did not exacerbate I. tomentosus effects. PC and UN had similar live tree density, but UN had lower dead tree density. In all stands, snag longevity was typically <32 years, and ~40 years was required for dead wood to reach decay stage 3 or greater. UN was characterized by variable severity disturbances averaging ~8% of the canopy per decade. Management implications include the following: (i) harvest systems designed to emulate small-scale disturbance could remove trees at 8% of the canopy per decade, varied spatiotemporally, (ii) emulating dead wood abundance with partial cutting may be difficult given the impacts of partial cutting on dead wood abundance, and (iii) forests with moderate levels of I. tomentosus should not respond differently to harvesting than uninfected forests and thus require no special management.

Growth of Advance Regeneration in Response to Residual Overstory Treatment in Northern Idaho

1992 ◽  
Vol 7 (3) ◽  
pp. 78-81 ◽  
Author(s):  
John H. Bassman ◽  
John C. Zwier ◽  
John R. Olson ◽  
James D. Newberry
Keyword(s):  
Natural Regeneration ◽  
Growth Response ◽  
Basal Area ◽  
Height Growth ◽  
Subsequent Growth ◽  
Advance Regeneration ◽  
Residual Tree ◽  
Highly Correlated ◽  
Northern Idaho ◽  
Brush Height

Abstract The effects of killing a low-volume residual overstory on growth of advance natural regeneration in North Idaho were assessed. Killing this overstory had little effect on subsequent growth of advance regeneration regardless of the basal area killed. Growth of regeneration following release was affected by competition from other advance regeneration and competition from brush. Height-growth response was negligible when density of either advance regeneration or brush were high. Residual tree killing was associated with improved crown vigor of regeneration where residual overstory basal area was high. Height growth of advance regeneration following residual tree killing was highly correlated with prerelease height growth and current crown vigor of advance regeneration. West. J. Appl. For. 7(3):78-81.

Windthrow following four harvest treatments in an Engelmann spruce - subalpine fir forest in southern interior British Columbia, Canada

1999 ◽  
Vol 29 (10) ◽  
pp. 1547-1556 ◽  
Author(s):  
David J Huggard ◽  
Walt Klenner ◽  
Alan Vyse
Keyword(s):  
Large Scale ◽  
Basal Area ◽  
Random Trees ◽  
Abies Lasiocarpa ◽  
Ecological Processes ◽  
Individual Tree ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Lower Height

We used transect surveys at a large-scale experimental site at Sicamous Creek, B.C., to measure the effects of five treatments on windthrow: 10-ha clearcuts, arrays of 1-ha patch cuts, arrays of 0.1-ha patch cuts, individual-tree selection cuts, and uncut controls. We also examined edge effects and conditions predisposing trees to windthrow. Windthrow of subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in the 2.7 years following harvesting increased from 0.6% of basal area per year in uncut forest to 0.8-1.8% per year in harvested treatments, with highest rates in individual tree selection units and lowest rates in 0.1-ha patch-cut arrays. Engelmann spruce (Picea engelmannii Parry ex Engelm.) showed similar patterns of windthrow but lower rates (0.2-0.7% of basal area per year in harvested treatments). Windthrow was concentrated near north and east edges of 1-ha and 10-ha openings but was dispersed throughout the more uniform treatments. Windthrown trees did not differ from random trees in diameter but had lower height/diameter ratios, probably reflecting the greater windthrow observed in subxeric sites on complex, elevated topography. The rates and distribution of windthrow in different harvest treatments have implications for ecological processes, salvage, long-term windthrow potential, and mitigation possibilities.

Genetic variation between and within populations of Engelmann spruce and subalpine fir

Genome ◽  
1990 ◽  
Vol 33 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Kathleen L. Shea
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Colorado Front Range ◽  
Abies Lasiocarpa ◽  
Front Range ◽  
Dispersal Patterns ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Inbreeding Coefficients

The genetic structure of Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) in two adjacent sites in the Colorado Front Range was examined using allozyme data from 21 loci in spruce and 18 loci in fir. The genetic diversity measures of alleles per locus, percent loci polymorphic, and mean heterozygosity did not differ significantly between or within species. However, the observed heterozygosity (0.126 spruce, 0.081 fir) values suggest that Engelmann spruce is more genetically variable than subalpine fir. Mean inbreeding coefficients were twice as high in fir as in spruce (FIS = 0.154 spruce, 0.341 fir). There were significant differences in allele frequencies in both species between and within sites, and among age-classes, with spatial differences greater than temporal differences. F-statistics showed greater genetic differentiation within (FST = 2.3–2.6% spruce, 2.0–2.8% fir) than between sites (FST = 1.7% spruce, 1.3% fir). Both species had higher FST and genetic distance values, yet lower FIS values, for spatial subdivisions within rather than between sites. This pattern suggests that the size of a spatial subdivision, where maximum gene flow is 54 m, approximates the size of the largest panmictic unit. In contrast with studies on other conifers, these results suggest that factors such as differential selection pressures, seed dispersal patterns, and clumped spatial distribution have resulted in genetic differentiation at the microhabitat level in Engelmann spruce and subalpine fir.Key words: genetic variation, genetic structure, allozymes, Engelmann spruce, subalpine fir, microgeographic differentiation.

Height growth–elevation relationships in subalpine forests of interior British Columbia

1996 ◽  
Vol 72 (2) ◽  
pp. 193-198 ◽  
Author(s):  
K. Klinka ◽  
H. Y. H. Chen ◽  
Q. Wang ◽  
R. E. Carter
Keyword(s):  
British Columbia ◽  
Growth Curves ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Picea Engelmannii ◽  
Abies Lasiocarpa ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Study Species

Stem analysis data from even-aged Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir [Abies lasiocarpa (Hook.) Nutt.] stands on zonal sites in the Engelmann Spruce—Subalpine Fir biogeoclimatic zone of British Columbia were used to examine the relationships of site index and height growth and elevation, latitude, and longitude. Elevation and latitude were found to be strongly negatively correlated with site index of both study species. Spruce site index (bh age 50) was predicted to decrease 2.9 m and fir site index 2.5 m with every 100 m and 1° increase in elevation and latitude, respectively; however, (i) site index of both species appeared to decline faster with increasing latitude than elevation, and (ii) decrease appeared to be faster for spruce than for fir. Comparison of height growth curves for stands on zonal and azonal sites with similar site index from different elevations and latitudes suggested that there are probably inconsequential differences between the shape of curves for either species. These findings imply that (i) subalpine fir is better adapted to subalpine boreal climates than Engelmann spruce and (ii) development of polymorphic site index curves for estimating site index of both species may be appropriate. Key words: elevation, latitude, longitude, site index, height growth, Abies lasiocarpa, Picea engelmannii, Engelmann Spruce—Subalpine Fir zone

Advanced regeneration and seedling establishment in small cutblocks in high-elevation spruce–fir forest at Sicamous Creek, southern British Columbia

2005 ◽  
Vol 35 (8) ◽  
pp. 1877-1888 ◽  
Author(s):  
Roberta Parish ◽  
Joseph A Antos
Keyword(s):  
British Columbia ◽  
Natural Regeneration ◽  
Survival Rates ◽  
Forest Edge ◽  
High Elevation ◽  
Abies Lasiocarpa ◽  
Advanced Regeneration ◽  
Engelmann Spruce ◽  
Similar Survival ◽  
New Recruits

We examined the potential of natural regeneration for stocking 1-ha patch cuts in high-elevation Engelmann spruce (Picea engelmannii Parry) – subalpine fir (Abies lasiocarpa (Hook.) Nutt.) forests. Using the Sicamous Creek Silvicultural Systems site, which was harvested during winter 1994–1995, we established 1-m2 plots in patch cuts, forest edge, and untreated control forest. We marked and recorded microsite characteristics for all advanced regeneration and new recruits for up to 5 years; over 12 000 individuals were included. Advanced regeneration was abundant and was about one-quarter spruce. Spruce and fir germinants occurred in all years, but numbers varied greatly, with a very large cohort in 1998. Both advanced regeneration and new recruits were concentrated on decaying logs. Mortality of advanced regeneration was high in the patch cuts following harvest, but subsequent survival was good, approaching rates in the untreated forest within 4 years. Survival rates were higher for spruce than fir, but differed little among surface types and microtopographic positions. Survival of new recruits was high, approximately 50% the first year and 70% during the second, and was similar between spruce and fir. If the 1998 cohort has similar survival, the patch cuts could be adequately stocked. Use of natural regeneration, in combination with infill planting, is a viable option for stocking small openings in wet high-elevation forests in southern British Columbia.

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