Static tests of lodgepole pine stability in the central interior of British Columbia

1996 ◽  
Vol 26 (8) ◽  
pp. 1463-1472 ◽  
Author(s):  
M.J. Krasowski ◽  
C.D.B. Hawkins ◽  
H. Coates ◽  
P.K. Ott

Lodgepole pine (Pinuscontorta Dougl. ex Loud. var. latifolia Engelm.) static stability was examined on six central interior British Columbia forest sites using dynamometer testing. Stand ages ranged from 11 to 21 years. The same number of tests were done in each cardinal direction. Two forces were measured: (i) first sign of destabilization (root plate movement or a loud cracking sound); (ii) maximum force recorded during uprooting. Forces were converted to turning moments of destabilization (M1) and complete uprooting (M2). On one site, trees planted as bare-root stock were significantly more firm (M1) than those planted as Styroblock stock, but differences were insignificant on two other sites. There were no differences in M2 between these stock types. No differences were observed among chemically root-pruned planting stock and the two above stock types. On coarse, sandy soil, M1 and M2 were small. On the same site, trees on slopes were less stable (when pulled down slope) than those growing on flat terrain. Naturally regenerated trees in a dense unthinned stand had a smaller M1 than nearby planted trees. However, in a natural stand thinned 1 year before testing, M1 did not differ between naturals and planted stock. Trees germinated in peat blocks and planted before roots had incurred air pruning had significantly greater M1 values than comparable Styroblock stock, but M2 values were not different. Rather than stock type, soil properties and stocking density are likely the prime determiners of stand stability.

1982 ◽  
Vol 12 (3) ◽  
pp. 567-575 ◽  
Author(s):  
S. Eis ◽  
D. Craigdallie ◽  
C. Simmons

Height, diameter, volume growth, crown width, and stocking of lodgepole pine (Pinuscontorta Dougl.) and white spruce (Piceaglauca (Moench) Voss) were studied on the three most common forest sites in the central interior of British Columbia, to estimate their potential growth and their suitability for pure or mixed stands in managed second-growth forests established by planting. Spruce only should be planted on moist to wet Alluvium sites; both species appear to be equally suitable on moist Aralia sites, and pine only should be planted on dry to moist Cornus–Moss sites. In mixed forest, suppressed spruce will have little volume at the time of pine harvest. In general, managed, fully stocked second-growth forests should produce greater volume per hectare than the present natural, unmanaged forests.


1997 ◽  
Vol 27 (4) ◽  
pp. 618
Author(s):  
M J Krasowski ◽  
C DB Hawkins ◽  
H Coates ◽  
P K Ott

2015 ◽  
Vol 105 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Kennedy Boateng ◽  
Kathy J. Lewis

We studied spore dispersal by Dothistroma septosporum, causal agent of a serious outbreak of red band needle blight in lodgepole pine plantations in northwest British Columbia. Spore abundance was assessed at different distances and heights from inoculum sources and microclimatic factors were recorded during two consecutive years. Conidia were observed on spore traps from June to September during periods of rainfall. It was rare to detect spores more than 2 m away from inoculum sources. The timing and number of conidia dispersed were strongly tied to the climatic variables, particularly rainfall and leaf wetness. Should the trend toward increased spring and summer precipitation in the study area continue, the results suggest that disease spread and intensification will also increase. Increasing the planting distances between lodgepole pine trees through mixed species plantations and overall reduction in use of lodgepole pine for regeneration in wet areas are the best strategies to reduce the spread of the disease and enhance future productivity of plantations in the study area.


2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Teresa A. Newsome ◽  
Jean L. Heineman ◽  
Amanda F. Linnell Nemec

Critical height ratios for predicting competition between trembling aspen and lodgepole pine were identified in six juvenile stands in three south-central British Columbia ecosystems. We used a series of regression analyses predicting pine stem diameter from the density of neighbouring aspen in successively shorter relative height classes to identify the aspen-pine height ratio that maximizedR2. Critical height ratios varied widely among sites when stands were 8–12 years old but, by age 14–19, had converged at 1.25–1.5. MaximumR2values at age 14–19 ranged from 13.4% to 69.8%, demonstrating that the importance of aspen competition varied widely across a relatively small geographic range. Logistic regression also indicated that the risk of poor pine vigour in the presence of aspen varied between sites. Generally, the degree of competition, risk to pine vigour, and size of individual aspen contributing to the models declined along a gradient of decreasing ecosystem productivity.


2019 ◽  
Vol 45 (6) ◽  
Author(s):  
Kelby Fite ◽  
Liza Holmes ◽  
Elden LeBrun

Tree root defects from current nursery production practices influence short- and long-term tree performance and survivability. The Missouri Gravel Bed (MGB) system, a production method using gravel as a substrate, has been used to prevent many of these defects from occurring. MGB production involves planting bare root stock into a bed of gravel with frequent drip irrigation in order to produce a root system with relatively few defects. MGB production methods have also been purported to allow for summer transplanting of many species, as opposed to traditional dormant transplanting.Because gravel has low water- and nutrient-holding capacity, biochar (5% by volume) was incorporated into one plot as a possible means of improving both water- and nutrient-holding capacity over gravel alone. Wood chip mulch was also investigated as a growing substrate in place of the gravel in a growing system. In 2015, three species, Quercus bicolor (swamp white oak), Taxodium distichum (baldcypress), and Tilia cordata (littleleaf linden), were studied in pea gravel (PG), biochar-amended pea gravel (BC), and wood chip mulch bed (MB) growing environments. Very few differences occurred over the growing season with above- or belowground parameters indicating that the minimal-to-no-cost, more readily available substrate of wood chip mulch should be considered in these growing systems.


2017 ◽  
Vol 54 (11) ◽  
pp. 1153-1164 ◽  
Author(s):  
B.H. Luckman ◽  
M.H. Masiokas ◽  
K. Nicolussi

As glaciers in the Canadian Rockies recede, glacier forefields continue to yield subfossil wood from sites overridden by these glaciers during the Holocene. Robson Glacier in British Columbia formerly extended below tree line, and recession over the last century has progressively revealed a number of buried forest sites that are providing one of the more complete records of glacier history in the Canadian Rockies during the latter half of the Holocene. The glacier was advancing ca. 5.5 km upvalley of the Little Ice Age terminus ca. 5.26 cal ka BP, at sites ca. 2 km upvalley ca. 4.02 cal ka BP and ca. 3.55 cal ka BP, and 0.5–1 km upvalley between 1140 and 1350 A.D. There is also limited evidence based on detrital wood of an additional period of glacier advance ca. 3.24 cal ka BP. This record is more similar to glacier histories further west in British Columbia than elsewhere in the Rockies and provides the first evidence for a post-Hypsithermal glacier advance at ca. 5.26 cal ka BP in the Rockies. The utilization of the wiggle-matching approach using multiple 14C dates from sample locations determined by dendrochronological analyses enabled the recognition of 14C outliers and an increase in the precision and accuracy of the dating of glacier advances.


Botany ◽  
2019 ◽  
Vol 97 (1) ◽  
pp. 23-33
Author(s):  
Paul Y. de la Bastide ◽  
Jonathon LeBlanc ◽  
Lisheng Kong ◽  
Terrie Finston ◽  
Emily M. May ◽  
...  

Lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Watson) is an important lumber species in Canada, and seed orchards are expected to meet the increased demand for seed. However, seed production has been consistently low in the Okanagan region orchards of British Columbia, Canada. To determine whether the fungal microbiome contributes to seed loss, histological and molecular approaches were used. Seed production was studied at seven Okanagan orchards, all outside the natural range of lodgepole pine, and at one near Prince George, within its natural range. Seed losses were highest in the Okanagan, compared with Prince George. The role of fungal colonizers in consuming seed during the last stages of maturation is described. Fungal hyphae were frequently observed at all locations in developing seed, particularly once storage substances accumulated. Fungi identified from host tissues using molecular and morphological techniques included Alternaria, Cladosporium, Fusarium, Penicillium, and Sydowia. The opportunistic foliar pathogen Sydowia polyspora, which is known to have a variable biotrophic status, was detected at most orchards within different host tissues (seeds, needles, and conelets), in association with pollen, and in the air column. Reduced seed viability observed in Okanagan orchards is most likely due to a combination of factors, including composition of the fungal microbiome.


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