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.

Wind and snow damage nine years following four harvest treatments in a subalpine fir – Engelmann spruce forest at Sicamous Creek in southern interior British Columbia, Canada

2008 ◽  
Vol 84 (3) ◽  
pp. 401-409 ◽  
Author(s):  
Alan Vyse ◽  
Christine Ferguson ◽  
David J Huggard
Keyword(s):  
Large Scale ◽  
Wind Damage ◽  
Picea Engelmannii ◽  
Abies Lasiocarpa ◽  
Spruce Forest ◽  
Individual Tree ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Snow Damage ◽  
Snow Loading

We used transect surveys at a large-scale experimental site at Sicamous Creek, B.C. to measure the effects of five treatments on wind and snow damage in an old subalpine fir – Engelmann spruce forest: 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 damage. Transects were surveyed in 1997, 1999 and 2003 (2.7, 4.7 and 8.7 years postharvest). The increase in wind damage in the four harvested treatments compared to the uncut controls observed after 2.7 years was no longer evident following a snow damage event in the winter of 1998–1999, which was most severe in the uncut controls and leave strips. The damage recorded from this event was predominantly stem snapping rather than uprooting. Subsequent damage was low in all treatments, returning to the level first recorded in the uncut controls. Overall, after 8.7 years, the treatment differences were not statistically significant but the lowest average rates of damage were observed in the 0.1-ha patch cut arrays. The highest damage rates overall were observed within 10 m of the N and E edges of the 10-ha clearcuts. Damage rates in Engelmann spruce continued to be lower than rates for subalpine fir. Stem snapping, caused by some combination of snow loading and wind, is an underreported but widespread disturbance in these stands. Key words: ESSF forest, wind damage, snow damage, snapping, uprooting, subalpine fir (Abies lasiocarpa [Hook] Nutt.), Engelmann spruce (Picea engelmannii Parry ex Engelm.), silvicultural systems, Sicamous Creek

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.

Is everything all right up there? A long-term interdisciplinary silvicultural systems project in a high elevation fir-spruce forest at Sicamous Creek, B.C.

1999 ◽  
Vol 75 (3) ◽  
pp. 467-472 ◽  
Author(s):  
Alan Vyse
Keyword(s):  
British Columbia ◽  
High Elevation ◽  
Wildlife Habitat ◽  
Spruce Forest ◽  
Individual Tree ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
South Central ◽  
Wide Range

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

Performance of planted Engelmann spruce and subalpine fir seedlings in British Columbia's southern mountains

2006 ◽  
Vol 82 (1) ◽  
pp. 84-94 ◽  
Author(s):  
C C Lajzerowicz ◽  
A. Vyse ◽  
M. Jull ◽  
T. Newsome
Keyword(s):  
British Columbia ◽  
Seedling Survival ◽  
High Elevation ◽  
Abies Lasiocarpa ◽  
Individual Tree ◽  
Relative Growth Rates ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
South Central ◽  
Soil Temperatures

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

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.

Assessing model performance in forecasting long-term individual tree diameter versus basal area increment for the primary Acadian tree species

2011 ◽  
Vol 41 (12) ◽  
pp. 2267-2275 ◽  
Author(s):  
Matthew B. Russell ◽  
Aaron R. Weiskittel ◽  
John A. Kershaw
Keyword(s):  
Random Effects ◽  
Mean Squared Error ◽  
Growth Models ◽  
Secondary Growth ◽  
Model Performance ◽  
Basal Area ◽  
Nonlinear Mixed Effects Models ◽  
Absolute Deviation ◽  
Individual Tree

Tree basal area (ba) or diameter at breast height (dbh) are universally used to represent tree secondary growth in individual tree based growth models. However, the long-term implications of using either ba or dbh for predictions are rarely fully assessed. In this analysis, Δba and Δdbh increment equations were fit to identical datasets gathered from six conifer and four hardwood species grown in central Maine. The performance of Δba and Δdbh predictions from nonlinear mixed-effects models were then compared with observed growth measurements of up to 29 years via a Monte Carlo simulation. Two evaluation statistics indicated substantial improvement in forecasting dbh using Δdbh rather than Δba. Root mean squared error (RMSE) and percentage mean absolute deviation (MAD%) were reduced by 14% and 15% on average, respectively, across all projection length intervals (5–29 years) when Δdbh was used over Δba. Differences were especially noted as projection lengths increased. RMSE and MAD% were reduced by 24% when Δdbh was employed over Δba at longer projection lengths (up to 29 years). Simulations found that simulating random effects rather than using local estimates for random effects performed as well or better at longer interval lengths. These results highlight the implications that selecting a growth model dependent variable can have and the importance of incorporating model uncertainty into the growth projections of individual tree based models.

The role of connectivity in Australian conservation

2004 ◽  
Vol 10 (4) ◽  
pp. 266 ◽  
Author(s):  
M. E. Soulé ◽  
B. G. Mackey ◽  
H. F. Recher ◽  
J. E. Williams ◽  
J. C. Z. Woinarski ◽  
...  
Keyword(s):  
Large Scale ◽  
Biological Diversity ◽  
Ecological Resilience ◽  
Landscape Permeability ◽  
Conservation Assessment ◽  
Ecological Processes ◽  
Trophic Relations ◽  
Scientific Framework

The existing system of nature reserves in Australia is inadequate for the long-term conservation and restoration of native biological diversity because it fails to accommodate, among other elements, large scale and long-term ecological processes and change, including physical and biotic transport in the landscape. This paper is an overview of the connectivity elements that inform a scientific framework for significantly improving the prospects for the long-term conservation of Australia's biodiversity. The framework forms the basis for the WildCountry programme. This programme has identified connectivity at landscape, regional and continental scales as a critical component of an effective conservation system. Seven categories of ecological phenomena are reviewed that require landscape permeability and that must be considered when planning for the maintenance of biological diversity and ecological resilience in Australia: (1) trophic relations at regional scales; (2) animal migration, dispersal, and other large scale movements of individuals and propagules; (3) fire and other forms of disturbance at regional scales; (4) climate variability in space and time and human forced rapid climate change; (5) hydroecological relations and flows at all scales; (6) coastal zone fluxes of organisms, matter, and energy; and, (7) spatially-dependent evolutionary processes at all scales. Finally, we mention eight cross-cutting themes that further illuminate the interactions and implications of the seven connectivity-related phenomena for conservation assessment, planning, research, and management, and we suggest how the results might be applied by analysts, planners, scientists, and community conservationists.

scholarly journals Large-scale forest landscape model, design, validation, and application in management of oak decline

2012 ◽  
Author(s):  
◽  
Wenjuan Wang
Keyword(s):  
Forest Inventory ◽  
Large Scale ◽  
Basal Area ◽  
Model Parameters ◽  
Forest Landscape ◽  
Oak Decline ◽  
Model Predictions ◽  
Forest Landscape Model ◽  
Landis Pro

Forest landscape models (FLMs) have increasingly become important tools for exploring forest landscape changes by predicting forest vegetation dynamics over large spatial scales. However, two challenges confronting FLMs have persisted: how to simulate fine, site-scale processes while making large-scale (landscape and regional) simulation feasible, and how to fully take advantage of extensive U.S. Forest Service Inventory and Analysis (FIA) data to initialize and constraint model parameters. In this dissertation, first, a new FLM, LANDIS PRO was developed. In LANDIS PRO, forest succession and dynamics are simulated by incorporating species-, stand-, and landscape-scale processes by tracking number of trees by species age cohort. Because stand-scale resource competition is achieved by implementing rather than simulating the emergent properties of stand development, LANDIS PRO is computationally efficient, which makes large-scale simulation feasible. Since model parameters and simulation results are comparatively straightforward to forest inventory data, current intensive forest inventory data can be directly applied for model initialization and to constrain model parameters. Validation of FLMs is essential to ensure users’ confidence in model predictions and achieve reliable management decision making. To date, validation of FLMs has been limited due to lack of suitable data. However, recent advances in FLMs, together with increasingly available spatiotemporal data make FLM validation feasible. In this dissertation, second, I proposed a framework for validating forest landscape projections from LANDIS PRO using Forest Inventory Analysis (FIA) data. The proposed framework incorporated data assimilation techniques to constrain model parameters and the initial state of the landscape by verifying the initialized landscape and iteratively calibrating the model parameters. The model predictions were rigorously validated against independent FIA data at multiple scales, and the long-term natural successional pattern was also verified against empirical studies. Results showed model predictions were able to capture much of the variation overtime in species basal area and tree density at stand-, landtype- , and landscape-scales. Subsequent long-term predictions of natural succession patterns were consistent with expected changes in tree species density of oak-dominated forests in the absence of disturbance. Lastly, I used LANDIS PRO, a forest landscape model that includes stand-scale species density and basal area to evaluate the potential landscape-scale effects of alternative harvest methods (thinning, clearcutting and group selection) on oak decline mitigation. Projections indicated that forest harvesting can be effective in mitigating oak decline. Group selection and clearcutting were the most effective methods in the management of oak decline in the short-term (20 years) and mid-term (50 years), respectively. However, in the long-run (100 years), there was no significant difference predicted among the three methods.

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