Genetic Differentiation among Growth Forms of Engelmann Spruce and Subalpine Fir at Tree Line

1977 ◽  
Vol 9 (3) ◽  
pp. 259 ◽  
Author(s):  
Michael C. Grant ◽  
Jeffry B. Mitton
Keyword(s):  
Genetic Differentiation ◽  
Tree Line ◽  
Growth Forms ◽  
Subalpine Fir ◽  
Engelmann Spruce

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.

Effects of harvesting on fine root biomass and decomposition in an Engelmann spruce – subalpine fir forest

2003 ◽  
Vol 33 (5) ◽  
pp. 847-853 ◽  
Author(s):  
Sylvia E Welke ◽  
Graeme D Hope ◽  
Gary A Hunt
Keyword(s):  
Root Biomass ◽  
Fine Root ◽  
Timber Harvesting ◽  
High Elevation ◽  
Fine Root Biomass ◽  
Nutrient Concentrations ◽  
Root Dynamics ◽  
Subalpine Fir ◽  
Root Longevity ◽  
Engelmann Spruce

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.

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.

Simulated conversion of unmanaged interior spruce-subalpine fir stands to a regulated uneven-aged structure

2000 ◽  
Vol 76 (3) ◽  
pp. 465-474 ◽  
Author(s):  
Craig Farnden
Keyword(s):  
Old Growth ◽  
Individual Tree ◽  
Subalpine Fir ◽  
High Q ◽  
Engelmann Spruce ◽  
Management Objectives ◽  
Individual Tree Growth ◽  
Interior Spruce ◽  
Growth Attributes ◽  
Tree Growth Model

A localized version of the Forest Vegetation Simulator (FVS) individual tree growth model was developed to simulate stand level impacts under a variety of uneven-aged management regimes in old-growth interior spruce-subalpine fir forests near Prince George British Columbia. Options for using uneven-aged management to satisfy a range of management objectives were simulated using different sets of BDq regulation parameters, and by varying species composition and rules for reserve trees. The greatest timber yields were attained by promoting the highest possible spruce component, using high q ratios, low to moderate maximum diameters and 20 to 25 year cutting cycles, and allowing no reserves. Using strategies to promote stand structures maintaining some old-growth attributes resulted in much lower timber yields. Key words: white spruce, Engelmann spruce, subalpine fir, uneven-aged management, BDq regulation, simulated yield

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.

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