Characteristics and densities of Williamson’s Sapsucker nest trees in British Columbia

2009 ◽  
Vol 39 (12) ◽  
pp. 2319-2331 ◽  
Author(s):  
L. W. Gyug ◽  
C. Steeger ◽  
I. Ohanjanian
Keyword(s):  
British Columbia ◽  
Endangered Species ◽  
Populus Tremuloides ◽  
Stand Structure ◽  
Tree Density ◽  
Trembling Aspen ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Term Maintenance

We characterized Williamson’s Sapsucker ( Sphyrapicus thyroideus (Cassin, 1852)) nest trees in southern British Columbia from 1995 to 2008 to determine the nesting requirements of this endangered species in Canada. In the East Kootenay (n = 32) and the Okanagan (n = 157) regions where western larch ( Larix occidentalis Nutt.) occurred, 81% and 75% of the nest trees were western larch, respectively. In regions west of the Okanagan Valley where western larch did not occur (n = 73), 77% of the nest trees were trembling aspen ( Populus tremuloides Michx.). Conifer nest trees were larger (72 cm DBH), on average, than broad-leaved nest trees (35 cm DBH), and this pattern was consistent across the breeding range of Williamson’s Sapsucker. Live western larch >67 cm DBH with either broken or dead tops were the trees with the highest frequency (20%) among the trees estimated to be suitable for nesting, primarily because these larch tended to be infected with heart rots. Based on observed densities, targets should be 1.36 suitable nest trees/ha in managed stands, although in many instances such as aspen patches, this target will only be met in portions of the nesting territories. The recommended stand structure for long-term maintenance of high nest-tree density in western larch stands is for ≥20 trees/ha with DBHs >57 cm and 60–150 trees/ha with DBHs >22 cm.

Decadal observations of tree regeneration following fire in boreal forests

2004 ◽  
Vol 34 (2) ◽  
pp. 267-273 ◽  
Author(s):  
Jill F Johnstone ◽  
F S Chapin III ◽  
J Foote ◽  
S Kemmett ◽  
K Price ◽  
...  
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Boreal Forests ◽  
Pinus Contorta ◽  
Stand Structure ◽  
Stand Density ◽  
Tree Regeneration ◽  
Direct Observations ◽  
Highly Correlated

This paper presents data on early postfire tree regeneration. The data were obtained from repeated observations of recently burned forest stands along the Yukon – British Columbia border and in interior Alaska. Postfire measurements of tree density were made periodically for 20–30 years, providing direct observations of early establishment patterns in boreal forest. Recruitment rates of the dominant tree species in both study areas were highest in the first 5 years after fire, and additional net establishment was not observed after 10 years. The postfire population of spruce (Picea mariana (Mill.) BSP and Picea glauca (Moench) Voss s.l.) remained constant after the first decade in the two study areas. Populations of aspen (Populus tremuloides Michx.) and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) both declined after 10 years in mixed-species stands along the Yukon – British Columbia border. Mortality rates of aspen and pine were positively correlated with their initial densities, indicating that thinning occurred as a density-dependent process. At all sites, measurements of stand density and composition made early were highly correlated with those made late in the monitoring period, indicating that patterns of stand structure initiated within a few years after fire are maintained through subsequent decades of stand development.

A shoot-blight disease of western larch in British Columbia

1969 ◽  
Vol 47 (10) ◽  
pp. 1509-1511 ◽  
Author(s):  
A. Funk
Keyword(s):  
British Columbia ◽  
Biological Characteristics ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Shoot Blight ◽  
Blight Disease

Encoeliopsis laricina (Ettlinger) Groves is shown to be the chief fungus associated with a shoot-blight disease of western larch (Larix occidentalis Nutt.) in the Kootenay region of British Columbia, Canada. Symptoms are described and biological characteristics of the fungus are given.

Some Wood-Inhabiting Yeasts of Trembling Aspen (Populus tremuloides) from Alberta and Northeastern British Columbia

Mycologia ◽  
1994 ◽  
Vol 86 (3) ◽  
pp. 386 ◽  
Author(s):  
Leonard J. Hutchison ◽  
Yasuyuki Hiratsuka
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Trembling Aspen

scholarly journals Long-term precommercial thinning effects on Larix occidentalis (western larch) tree and stand characteristics

2017 ◽  
Vol 47 (7) ◽  
pp. 861-874 ◽  
Author(s):  
Michael S. Schaedel ◽  
Andrew J. Larson ◽  
David L.R. Affleck ◽  
R. Travis Belote ◽  
John M. Goodburn ◽  
...  
Keyword(s):  
Tree Growth ◽  
Tree Level ◽  
Recent Measurement ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Individual Tree ◽  
Precommercial Thinning ◽  
Linear Contrasts ◽  
Stand Yield

Precommercial thinning (PCT) is used to increase tree size and shorten harvest rotation time. Short-term results from PCT studies often show a trade-off between individual-tree growth and net stand yield, while longer-term effects of PCT on tree growth and stand yield are less well documented. We used a 54-year-old PCT study to test long-term effects of forest density and thinning schedules on stand yield and tree-level characteristics in even-aged western larch (Larix occidentalis Nutt.) stands. The study has three target densities (494, 890, and 1680 trees·ha−1) crossed with three thinning schedules (target density achieved through one, two, or four entries). Analysis of variance (ANOVA) and linear contrasts were used to test the effects of density and number of entries on tree- and stand-level attributes. Thinning before stand age 10 years leads to long-term constant yield (219.0–269.5 m3·ha−1; P > 0.05) across the tested densities. We also found constant volume growth across stand densities during the most recent measurement interval (5.42–6.41 m3·ha−1·year−1; P > 0.05). Number of entries did not affect any tree- or stand-level attribute. The primary effect of early PCT is to control whether wood volume and growth are concentrated on few large, stable trees or spread over many small, unstable trees.

Tree species selection revisited for plantations in the Interior Cedar Hemlock zone of southern British Columbia

2013 ◽  
Vol 89 (03) ◽  
pp. 382-391 ◽  
Author(s):  
Alan Vyse ◽  
Michelle R. Cleary ◽  
Ian R. Cameron
Keyword(s):  
British Columbia ◽  
Lodgepole Pine ◽  
Douglas Fir ◽  
Species Selection ◽  
Thuja Plicata ◽  
Pinus Monticola ◽  
White Pine ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Western White Pine

We provide results from two trials comparing performance of species of known provenance planted on logged sites in the southern Interior Cedar Hemlock biogeoclimatic zone of southern British Columbia 20 and 26 years after establishment. The commonly used plantation species, lodgepole pine (Pinus contorta var. latifolia), interior spruce (a naturally occurring hybrid between Picea glauca and P. engelmannii) and Douglas-fir (Pseudotsuga menziesii var. glauca), survived as well as, but grew more slowly than, western larch (Larix occidentalis), western white pine (Pinus monticola) and ponderosa pine (Pinus ponderosa), and faster than western redcedar (Thuja plicata). Site index values were generally higher than published values for similar sites. Numerous pests affected all species in the trials. Mountain pine beetle (Dendroctonus ponderosae) caused heavy mortality in lodgepole pine in part of one trial, and Armillaria root disease caused widespread damage to western larch and Douglas-fir in the other trial. Western white pine from local seed sources were severely damaged by white pine blister rust (Cronartium ribicola) in both trials but a rust-resistant seed source used in one trial survived better. Frost damage reduced survival and growth of Douglas-fir in one trial and may have affected western white pine. Survival of two planted broadleaves (Betula papyrifera) and a hybrid of black cottonwood (Populus trichocarpa) and black poplar (Populus nigra) was severely reduced by drought. The results support ongoing efforts to broaden the number of species used in British Columbia reforestation programs.

scholarly journals Height Growth Models for Western Larch in British Columbia

2002 ◽  
Vol 17 (2) ◽  
pp. 66-74 ◽  
Author(s):  
David Brisco ◽  
Karel Klinka ◽  
Gordon Nigh
Keyword(s):  
British Columbia ◽  
Growth Models ◽  
Growth Curves ◽  
Site Index ◽  
Height Growth ◽  
Larix Occidentalis ◽  
Local Data ◽  
Western Larch ◽  
Richards Model ◽  
Fit Statistics

Abstract British Columbia's foresters currently use height growth curves developed with data from Montana to estimate the height and productivity of western larch (Larix occidentalis). The ability of the presently used curves to accurately predict the height growth of British Columbia's larch population is unknown. The production of new curves with local data could improve our ability to predict heights and allow increasingly precise yield projections in British Columbia. Data from 105 western larch stem analysis plots were collected from across the natural range of larch in British Columbia. The measured plots were naturally established, fire-origin, even-aged, and exhibited no indications of suppression or disease. A Richards function was fit to the data from each plot and used to generate height-age and site index information. Four models were fit to the plot data: conditioned logistic, Chapman Richards, conditioned Chapman Richards, and conditioned Weibull. The Chapman Richards model had the best fit to the data, although all four models had similar fit statistics. Overall, the Chapman Richards model is slightly more accurate at estimating heights than the currently used model. West.J. Appl. For. 17(2):66–74.

Juvenile stand responses and potential outcomes of conifer release efforts on Alberta's spruce–aspen mixedwood sites

2004 ◽  
Vol 80 (5) ◽  
pp. 583-597 ◽  
Author(s):  
Douglas G Pitt ◽  
Milo Mihajlovich ◽  
Leslie M Proudfoot
Keyword(s):  
Growth Model ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Stand Structure ◽  
Landscape Management ◽  
Basal Area ◽  
White Spruce ◽  
Trembling Aspen ◽  
Management Objectives ◽  
Boreal Mixedwoods

Twelve Alberta forest regeneration blocks, situated on representative white spruce (Picea glauca (Moench) Voss) - trembling aspen (Populus tremuloides Michx.) boreal mixedwood sites, planted to white spruce, and operationally released with glyphosate herbicide, were surveyed in the fall of 2002. Stand structure and composition were quantified and compared for treated and untreated portions of each block. The Mixedwood Growth Model (MGM, Department of Renewable Resources, University of Alberta) was used to project these stands over a 100-year horizon and to model the outcomes of several additional silvicultural treatments that could be applied to these blocks. A single release treatment provided 17% and 43% gains in planted white spruce height and stem diameter, respectively, an average of five years after treatment. Treatment shifted stands from being deciduous-dominated, with only 12% conifer basal area, to more than 75% conifer basal area, increasing conifer volumes per hectare nearly three-fold, but retaining conifer-deciduous mixture. Model projections suggest that these stands will produce similar total volumes over an 80-year rotation and that conifer release essentially trades deciduous volume for conifer volume, the degree of release dictating the extent to which this trade-off takes place. A single conifer release treatment led to an average simulated mature stand that contains 21% deciduous basal area, likely meeting mixedwood rather than conifer regeneration criteria. Model simulations of additional silvicultural interventions in these stands suggested that a variety of options exist to satisfy a range of stand or landscape management objectives for spruce-aspen mixedwoods, all within a relatively fixed volume production envelope. A clearer understanding of how early stand conditions translate into stand and landscape management objectives seems prerequisite to solving management conflicts on boreal mixedwood sites. Key words: boreal mixedwoods, vegetation management, conifer release, Mixedwood Growth Model, white spruce, trembling aspen

The population structure of Armillaria ostoyae in the southern interior of British Columbia

2001 ◽  
Vol 79 (5) ◽  
pp. 612-620 ◽  
Author(s):  
Jeremy R Dettman ◽  
Bart J van der Kamp
Keyword(s):  
British Columbia ◽  
Population Structure ◽  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Random Mating ◽  
Geographic Distance ◽  
Symptom Expression ◽  
Armillaria Ostoyae ◽  
Term Maintenance

The population structure of Armillaria ostoyae (Romagn.) Herink was investigated at a study site in the interior cedar–hemlock zone of the southern interior of British Columbia. Eight 500-m long, randomly placed transects located at least 500 m apart were systematically sampled and individual genets were delineated using Random Amplified Polymorphic DNA (RAPD) analysis. Average genet intersect length was 79 m, and an estimated 88% of the area surveyed was occupied by genets <2 ha in size. The spatial distribution of genets in relation to one another was quite complex, with isolates of the same genet often non-contiguous along the transect. The location of genets could not be determined from aboveground symptom expression. Isolates collected from adjacent hosts within small groups of symptomatic hosts (infection foci) did not necessarily belong to the same genet, but single genets could occupy several infection foci. There was no relationship between geographic distance and genetic similarity of genets, suggesting random mating events for genet origin and long term maintenance of genetic identity.Key words: Armillaria, RAPD, population structure, genet, ramet, clone.

scholarly journals Widespread mortality of trembling aspen (Populus tremuloides) throughout interior Alaskan boreal forests resulting from a novel canker disease

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250078
Author(s):  
Roger W. Ruess ◽  
Loretta M. Winton ◽  
Gerard C. Adams
Keyword(s):  
Populus Tremuloides ◽  
Fungal Pathogens ◽  
Stand Structure ◽  
The United States ◽  
Leaf Miner ◽  
Summer Drought ◽  
Trembling Aspen ◽  
Interior Alaska ◽  
Incidence And Mortality ◽  
Paper Birch

Over the past several decades, growth declines and mortality of trembling aspen throughout western Canada and the United States have been linked to drought, often interacting with outbreaks of insects and fungal pathogens, resulting in a “sudden aspen decline” throughout much of aspen’s range. In 2015, we noticed an aggressive fungal canker causing widespread mortality of aspen throughout interior Alaska and initiated a study to quantify potential drivers for the incidence, virulence, and distribution of the disease. Stand-level infection rates among 88 study sites distributed across 6 Alaska ecoregions ranged from <1 to 69%, with the proportion of trees with canker that were dead averaging 70% across all sites. The disease is most prevalent north of the Alaska Range within the Tanana Kuskokwim ecoregion. Modeling canker probability as a function of ecoregion, stand structure, landscape position, and climate revealed that smaller-diameter trees in older stands with greater aspen basal area have the highest canker incidence and mortality, while younger trees in younger stands appear virtually immune to the disease. Sites with higher summer vapor pressure deficits had significantly higher levels of canker infection and mortality. We believe the combined effects of this novel fungal canker pathogen, drought, and the persistent aspen leaf miner outbreak are triggering feedbacks between carbon starvation and hydraulic failure that are ultimately driving widespread mortality. Warmer early-season temperatures and prolonged late summer drought are leading to larger and more severe wildfires throughout interior Alaska that are favoring a shift from black spruce to forests dominated by Alaska paper birch and aspen. Widespread aspen mortality fostered by this rapidly spreading pathogen has significant implications for successional dynamics, ecosystem function, and feedbacks to disturbance regimes, particularly on sites too dry for Alaska paper birch.

Nest tree use by primary cavity-nesting birds in south central British Columbia

1989 ◽  
Vol 67 (4) ◽  
pp. 1067-1073 ◽  
Author(s):  
Alton S. Harestad ◽  
Dagmar G. Keisker
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Douglas Fir ◽  
Trembling Aspen ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
South Central ◽  
Cavity Nesting ◽  
Picoides Pubescens ◽  
Colaptes Auratus

Heartwood decay was the most important factor in nest tree selection by primary cavity-nesting birds in the Interior Douglas-fir Biogeoclimatic Zone of British Columbia. Of 243 active nests, most were in trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera). Douglas-fir (Pseudotsuga menziesii) and hybrid spruce (Picea engelmannii × glauca) were not used for nesting. Strong excavators (Yellow-bellied Sapsucker (Sphyrapicus varius), Pileated Woodpecker (Dryocopus pileatus), and Hairy Woodpecker (Picoides villosus)) preferred to nest in live trembling aspen with heartwood decay. Weak excavators (Red-breasted Nuthatch (Sitta canadensis), Northern Flicker (Colaptes auratus), and Downy Woodpecker (Picoides pubescens)) preferred to nest in dead trees or dead tops of live trees. Yellow-bellied Sapsucker preferred to nest in trees larger than 30 cm diameter at breast height, and Pileated Woodpecker preferred trees larger than 40 cm diameter at breast height. No significant preference for nest tree diameter was detected for other species.

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