Temporal development of decaying log habitats in wet spruce–fir stands in east-central British Columbia

2005 ◽  
Vol 35 (12) ◽  
pp. 2841-2850 ◽  
Author(s):  
S Craig DeLong ◽  
Lori D Daniels ◽  
Ben Heemskerk ◽  
Ken Olaf Storaunet
Keyword(s):  
British Columbia ◽  
Picea Glauca ◽  
Model Development ◽  
Wildlife Habitat ◽  
Abies Lasiocarpa ◽  
Time Since Death ◽  
Morphological Attributes ◽  
East Central ◽  
Subalpine Fir ◽  
Advanced Stages

Time since death and time since fall were estimated for hybrid spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) logs to quantify temporal changes in log decay and habitat quality in east-central British Columbia. We sampled 136 logs (72 spruce and 64 fir) for species, size, and morphological attributes and used dendroecological techniques to estimate year of death (n = 97) and fall (n =  22). Time since death and time since fall of spruce and fir were similar in decay classes 1 and 2; fir was older than spruce in more advanced stages of decay. Discriminant analysis based on time since fall correctly classified logs into four decay classes for 67% and 80% of spruce and fir, respectively. Function as wildlife habitat changed significantly as logs decayed. Logs served as elevated runways for approximately 15 years and then increased in value as habitat for invertebrates and insectivores as wood softened and vegetation established. Concealed spaces increased as the wood decomposed but decreased when logs collapsed. We conclude that decay classes represent biologically and statistically significant stages of log decomposition that are relevant to wildlife habitat and therefore provide a useful construct for model development and field interpretation..

Predicting defoliation by Choristoneura biennis (Lepidoptera: Tortricidae)

2003 ◽  
Vol 135 (6) ◽  
pp. 903-907 ◽  
Author(s):  
V.G. Nealis ◽  
R. Turnquist
Keyword(s):  
British Columbia ◽  
Life Cycle ◽  
Linear Regression ◽  
Picea Glauca ◽  
Spruce Budworm ◽  
White Spruce ◽  
Prediction Intervals ◽  
Abies Lasiocarpa ◽  
Independent Data ◽  
Subalpine Fir

AbstractThe 2-year-cycle spruce budworm, Choristoneura biennis Free. (Lepidoptera: Tortricidae), causes defoliation of spruce – subalpine fir forests in British Columbia, Canada. Historical and newly obtained data were used to develop a linear regression relating percent defoliation in the 2nd feeding year of the life cycle to the percentage of shoots damaged in the previous, 1st feeding year of the life cycle. The resulting regression was tested with independent data and correctly predicted (95% prediction intervals) defoliation in 14 of 15 stands. Patterns of defoliation were similar on white spruce, Picea glauca (Moench) Voss (Pinaceae), and subalpine fir, Abies lasiocarpa (Hook.) Nutt. (Pinaceae), and hence the regression can be used for either mixed or pure stands of either species.

Estimating time since death of Picea glauca × P. engelmannii and Abies lasiocarpa in wet cool sub-boreal spruce forest in east-central British Columbia

2004 ◽  
Vol 34 (4) ◽  
pp. 931-938 ◽  
Author(s):  
J E Newberry ◽  
K J Lewis ◽  
M B Walters
Keyword(s):  
British Columbia ◽  
Tree Ring ◽  
Picea Glauca ◽  
Abies Lasiocarpa ◽  
Model Estimate ◽  
East Central ◽  
Dead Trees ◽  
Permanent Sample Plot ◽  
Ring Analysis ◽  
Understory Trees

A new method for studying stand disturbance regimes, which could be used alone or combined with other approaches (e.g., age class analysis, tree ring analysis, direct gap measurements), is presented. The method is a set of multiple regression models that estimate the year of death of trees on the basis of external characteristics (e.g., bark presence) and tree position (standing or down). The models were calibrated for Picea glauca (Moench) Voss × P. engelmannii Parry ex Engelm. and Abies lasiocarpa (Hook.) Nutt. trees with known dates of death determined from permanent sample plot data obtained from the Aleza Lake Research Forest, in east-central British Columbia, in the wet cool foothills of the Rocky Mountains. The P. glauca × P. engelmannii model explained 95.3% and 79.3%, and the A. lasiocarpa model explained 81.2% and 78.2%, of the variation in years since death for standing and down trees, respectively. The models were validated by an independent sample of dead trees, where the model estimate was compared with year of release determined from tree ring cores in subordinate understory trees. The two estimates were related (R2 = 61.3%, for both species), indicating that the model provides acceptable estimates for year of death in the two species. This approach may be particularly useful for determining year of death for trees that do not have subordinate individuals that release following overstory mortality.

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.

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

scholarly journals Vegetation Trends In Whitehorse Yukon, 1984 To 2009

2021 ◽  
Author(s):  
Dexter J. Kotylak
Keyword(s):  
Picea Glauca ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Landscape Scale ◽  
Leaf Miner ◽  
Abies Lasiocarpa ◽  
Land Area ◽  
Subalpine Fir ◽  
Ndvi Time Series ◽  
Phyllocnistis Populiella

To assess temporal greenness trends at the landscape scale for Whitehorse, Yukon (417 km2), this study derived a Landsat normalized difference vegetation index (NDVI) time-series from 1984 to 2009. Using a greenest annual pixel approach, NDVI trend analysis revealed that 37% of studied area had significant greening (p<0.05) and that only 1% of the studied land area had significant browning. Yearly mean NDVI values declined in drought years and increased in years with greater precipitation. Greening pixels were most prevalent in white spruce (Picea glauca) and subalpine fir (Abies lasiocarpa) dominant forests, suggesting that increased amounts of precipitation and rising temperatures have benefited both species and associated shrub communities. Forests where trembling aspen (Populas tremuloides) are dominant displayed the least greening, which may be explained by the proliferation of aspen serpentine leaf miner (Phyllocnistis populiella), and drought related die-back on south-facing slopes that have become warmer across the study period.

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

scholarly journals Improvements in Value Recovery through Low Stump Heights: Mechanized versus Manual Felling

2006 ◽  
Vol 21 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Ryan Hall ◽  
Han-Sup Han
Keyword(s):  
British Columbia ◽  
Picea Glauca ◽  
Stand Density ◽  
Abies Lasiocarpa ◽  
Potential Value ◽  
Value Recovery ◽  
Forest Practices ◽  
Value Loss ◽  
Manual Felling ◽  
Operational Constraints

Abstract Stump heights were measured on two blocks harvested during the summer of 2000 in north-central British Columbia. Each block was of similar stand and terrain characteristics, consisting mainly of subalpine fir (Abies lasiocarpa) with minor components of white spruce (Picea glauca × P. engelmannii) on gentle slopes. The blocks were harvested by two different contractors using different felling methods: mechanized felling with a feller-buncher and manual felling with a chainsaw. The average measured stump height from mechanized felling was 8.8 cm lower than that of manual felling, measuring 21.9 and 13.1 cm, respectively. When the saw kerf of felling equipment and stump-pull were included, the average stump height of mechanized felling was shown to be 5.8 cm (17%) lower than manual felling. High-end and low-end potential value losses were determined based on average sawlog values (Canadian [CN] $60/m 3 ) and pulp log values (CN$40/m 3 ), respectively. The potential value loss from manual felling was estimated to be up to CN$0.33/tree more than from mechanized felling. This result indicated that mechanized felling recovered up to CN$160/ha over manual felling when an average sawlog value and the stand density information from the study site were used in the calculation. The study demonstrated that lower stump heights than the 30 cm maximum stump height set by the Forest Practices Code of British Columbia are attainable with both felling methods. Sensitivity analysis was performed to determine the potential value and volume gains for a range of stump heights from 0 to 30 cm. Operational constraints were identified in the study, and recommendations for minimizing stump heights are presented.

Short-term impacts of partial cutting on lichen retention and canopy microclimate in an Engelmann spruce – subalpine fir forest in north-central British Columbia

2003 ◽  
Vol 33 (5) ◽  
pp. 830-841 ◽  
Author(s):  
Darwyn Coxson ◽  
Susan Stevenson ◽  
Jocelyn Campbell
Keyword(s):  
British Columbia ◽  
Sampling Techniques ◽  
Abies Lasiocarpa ◽  
Short Term ◽  
Partial Cutting ◽  
North Central ◽  
Subalpine Fir ◽  
Single Tree ◽  
Engelmann Spruce ◽  
Single Tree Selection

The retention of canopy lichens (Alectoria, Bryoria, and foliose) in group selection (GS) and single-tree selection (STS) partial cuts (30% removal) was studied within a subalpine spruce–fir forest (Picea englemannii Parry ex Engelm. – Abies lasiocarpa (Hook.) Nutt.) in north-central British Columbia. Baseline canopy lichen loading (preharvest and immediate postharvest) was compared with lichen loading 2 years after harvesting, using both ground- and canopy-based sampling techniques. Additionally, canopy microclimate was compared between GS and adjacent stand areas with no harvest treatment (NT). Partial cutting did not have a significant effect on lichen loading in residual trees, although a trend of declining lichen abundance was observed in each of the GS, STS, and NT areas. Partitioning of lichen abundance data showed significant postharvest declines for upper canopy STS Bryoria and smaller, but significant, changes in foliose lichen abundance in the NT and STS areas. No significant changes in canopy microclimate were observed between treatments, with the exception of south-facing aspects in GS trees, which showed reduced duration of lichen hydration. Taken together, these factors suggest that although the placement of Bryoria in residual trees may shift towards lower canopy exposures, partial-cut harvest treatments can maintain short-term lichen loading and associated ecosystem values (e.g., caribou forage) in subalpine spruce–fir stands.

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