scholarly journals Tree Growth Response Along Seismic Lines in Alberta

1986 ◽  
Vol 62 (1) ◽  
pp. 29-34 ◽  
Author(s):  
I. E. Bella
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Forest Cover ◽  
Black Spruce ◽  
Rocky Mountain ◽  
Radial Increment ◽  
Growth Data ◽  
Breast Height ◽  
Seismic Lines

Stem growth data from breast height were collected from about 2000 trees on 192 sample transects (plots) located adjacent to seismic lines. Sampled stands represented the most important forest cover types between 10 and 100 years of age over a range of site conditions in the foothills of western Albetra from Rocky Mountain House to Grande Prairie. Line clearing stimulated breast height radial increment fairly consistently in the 20% range of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) B.S.P.) trees. This improvement expressed in terms of stand growth, however, fell far short of that required to make up for the loss of wood production over these lines if the cut trees are not utilized. The lack of significant stimulation from line clearing in aspen (Populus tremuloides Michx.) stands indicates a complete loss of production due to the lines.

The effect of pedogenetic processes on the distribution of phosphorus, calcium and magnesium in Gray Luvisols

1991 ◽  
Vol 71 (4) ◽  
pp. 397-410 ◽  
Author(s):  
X. J. Xiao ◽  
D. W. Anderson ◽  
J. R. Bettany
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Formation ◽  
Podzolic Soils ◽  
Exchangeable Ca ◽  
Phosphorus Losses

Pedogenesis and its effect on calcium (Ca), magnesium (Mg) and phosphorus (P) was studied on a sequence of seven Gray Luvisol soils in central Saskatchewan. The soils were formed on calcareous glacial till under trembling aspen (Populus tremuloides Michx), mixedwood (aspen and white spruce) (Picea glauca (Moench) Voss)) and coniferous (black spruce and jack pine) (Picea mariana (Mill) BSP and Pinus banksiana Lamb) forests. Soils under aspen had the highest concentration of total and exchangeable Ca and Mg in litter layers and Ae horizons, and had Ae and Bt horizons that were least acidic. The most acidic Ae and Bt horizons and lowest amounts of Ca and Mg occurred under coniferous forests, whereas the soils under mixedwood stands were intermediate. The thickness of eluvial (Ae and AB) horizons increased along the aspen to coniferous sequence. All soils had about 40% less P in their A and B horizons than was calculated to have been present at the start of soil formation. The greatest decrease in P was observed in the thickest and most acidic soil under coniferous forest. The present litter layers and vegetation make up only a small proportion of the P removed from the mineral soil. Unusually large amounts of P appear to have been translocated from A and B horizons during development of Gray Luvisols, in comparison to Chernozemic or even Podzolic soils. Our hypothesis proposes that P is ineffectively retained in the solum as P-clay-humus, or iron-P complexes and that organic P moves along with the soil water, laterally and downslope through permeable Ae horizon over less permeable Bt horizons, or vertically through macropores. Key words: Boreal forest, nutrient cycling, phosphorus losses, weathering, soil formation

scholarly journals Site-index Curve Shape in Spruce

1969 ◽  
Vol 45 (3) ◽  
pp. 184-186 ◽  
Author(s):  
L. Heger
Keyword(s):  
Picea Glauca ◽  
Black Spruce ◽  
White Spruce ◽  
Site Index ◽  
Absolute Difference ◽  
Curve Shape ◽  
Breast Height ◽  
Maximum Absolute Difference ◽  
Site Index Curve ◽  
Index Curve

Sets of site-index curves were prepared from stem analyses of white spruce (Picea glauca (Moench) Voss) and black spruce (P. mariana (Mill.) BSP.) from various regions in the boreal forest of Canada. Ordinates of the site-index curves, computed for 5-year breast-height age intervals up to 75 years, and for 10-foot site-index intervals up to 70 feet, were compared within the species for the same values of site index and age. For breast-height ages below 55 years and for site index below 70 feet, the maximum absolute difference among the ordinates did not exceed 2.0 feet in white spruce, and 1.6 feet in black spruce; the corresponding average deviations were 0.75 and 0.80 feet. For breast-height ages above 55 years, these differences increased with age and, at 75 years, reached 8.8 feet in white spruce, and 3.8 feet in black spruce; the corresponding average deviations were 4.40 and 1.53 feet.

The Douglas-fir forests of Banff and Jasper National Parks, Canada

1970 ◽  
Vol 48 (10) ◽  
pp. 1703-1726 ◽  
Author(s):  
Paul W. Stringer ◽  
George H. La Roi
Keyword(s):  
National Parks ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Vegetation Change ◽  
Floristic Composition ◽  
Stand Age ◽  
Physical Habitat ◽  
Regression Equations ◽  
Habitat Differences

Twenty stands of uniform, mature, undisturbed Pseudotsuga menziesii var. glauca forest were selected in Banff and Jasper National Parks, using a combination of airphoto and ground surveys. Quantitative sampling methods were used to describe their floristic composition, vegetation structure, and physical habitats.Scattered trees of Pinus contorta, Picea glauca, and Populus tremuloides occurred in the Pseudotsuga forests. The poorly developed shrub strata contained Shepherdia canadensis, Rosa acicularis, Spiraea lucida, Juniperus communis. Major herb, dwarf shrub, bryophyte, and lichen species were Elymus innovatus, Calamagrostis rubescens, Fragaria virginiana, Astragalus decumbens, Aster conspicuus; Arctostaphylos uva-ursi, Linnaea borealis; Hylocomium splendens, Abietinella abietina, Tortula ruralis; Peltigera canina. A cyclical pattern of vegetation change is related to the death, replacement, and maturation of Pseudotsuga trees.Relations between vegetation and physical habitat were analyzed by simple correlation and multiple regression. Available potassium in soil, stand age, and slope exposure were most influential in regression equations for tree stratum development. Understory strata were primarily correlated with tree stratum development.A two-dimensional stand ordination based on the vegetational similarity of subordinate vascular strata showed a pronounced separation of Banff and Jasper Pseudotsuga forests, and prompted recognition of two new climax associations (sensu Daubenmire): Pseudotsuga / Elymus innovatus in Jasper; Pseudotsuga / Calamagrostis rubescens – Elymus innovatus in Banff. Habitat differences between the two associations include macroclimate, parent materials, and soil moisture.

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.

Boreal mixedwood tree growth on contrasting soils and disturbance types

2006 ◽  
Vol 36 (4) ◽  
pp. 986-995 ◽  
Author(s):  
Jennifer L Martin ◽  
Stith T Gower
Keyword(s):  
Populus Tremuloides ◽  
Tree Growth ◽  
Tree Species ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Jack Pine ◽  
Soil Types ◽  
Radial Increment ◽  
Mixedwood Forests ◽  
Increment Growth

Mixedwood forests are an ecologically and economically important ecosystem in the boreal forest of northern Canada. The objectives of this study were to (i) compare the age–height relationships for dominant tree species growing on two contrasting soil types and originating from different disturbances (logging versus wildfire), and (ii) determine the influence of competition on tree growth. Eight stands were selected that encompassed two age-classes replicated on two soil types (clay loam and sand) in a split-plot design. Four of the eight stands originated from logging (21–26 years old), and <F"Times">the four others originated from wildfires (80 years old). Nonlinear age–height analyses were used to compare annual height and radial increment growth of black spruce (Picea mariana (Mill.) BSP), jack pine (Pinus banksiana Lamb.), and trembling aspen (Populus tremuloides Michx.). Species, soil type, and size class explained significant amounts of the measured variation in the age–height models. Aspen, black spruce, and jack pine were 16%, 27%, and 19% taller, respectively, on clay soils than on sandy soils at the burned stand. Tree heights did not differ significantly among species or between soil types in logged stands. Diameter growth decreased as competition increased for black spruce and jack pine in the burned stands. The results for these three important boreal tree species are discussed in the context of sustainable forestry for boreal mixedwood forests.

Stem hydraulic properties and growth in lodgepole pine stands following thinning and sway treatment

2003 ◽  
Vol 33 (7) ◽  
pp. 1295-1303 ◽  
Author(s):  
Xiaodong Liu ◽  
Uldis Silins ◽  
Victor J Lieffers ◽  
Rongzhou Man
Keyword(s):  
Pinus Contorta ◽  
Hydraulic Properties ◽  
Lodgepole Pine ◽  
Specific Conductivity ◽  
Radial Increment ◽  
Total Leaf Area ◽  
Breast Height ◽  
Growing Seasons ◽  
Reduced Height ◽  
Fire Origin

The objective of this study was to explore the effects of wind-caused sway on the growth and stem hydraulic properties of fire-origin juvenile lodgepole pine (Pinus contorta Dougl. ex Loud.) stands after thinning. Nine plots were thinned and trees were treated to suppress or exacerbate sway from the wind: thinned and supported with a pole (TP), thinned with an added sail (TS), thinned control (TC), and unthinned control (UC). Terminal leader growth, radial increment, and earlywood and latewood widths at breast height were measured for the last six growing seasons. The specific hydraulic conductivity of stems was measured. The results showed that thinning increased diameter growth and reduced height growth and slenderness coefficient (particularly for trees with added sails) compared with the unthinned control. Trees from thinned stands had reduced specific conductivity compared with the trees from unthinned controls, suggesting that tree bending caused functional damage to sapwood. Specific conductivity was 1.36 × 10–5, 1.06 × 10–5, 0.96 × 10–5, and 0.83 × 10–5 m·s–1 in UC, TP, TC, and TS treatments, respectively. Trees from thinned stands, however, increased their total leaf area in the years following thinning.

Are mineral soils exposed by severe wildfire better seedbeds for conifer regeneration?

2006 ◽  
Vol 36 (8) ◽  
pp. 1943-1950 ◽  
Author(s):  
Kevin J Kemball ◽  
G. Geoff Wang ◽  
A Richard Westwood
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Seedling Recruitment ◽  
Black Spruce ◽  
Mineral Soil ◽  
White Spruce ◽  
Jack Pine ◽  
Conifer Regeneration ◽  
Mineral Soils

We examined jack pine (Pinus banksiana Lamb.), black spruce (Picea mariana (Mill.) BSP), and white spruce (Picea glauca (Moench) Voss) seed germination and seedling recruitment in aspen (Populus tremuloides Michx.) and conifer mixedwood stands following the 1999 Black River fire in southeastern Manitoba, Canada. Three postfire seedbed types were tested: scorched (surface litter only partially consumed), lightly burned (surface litter consumed with little or no duff consumption), and severely burned (complete consumption of litter and duff exposing mineral soil). Seeds were sown in 1999, 2000, and 2001, and each cohort was monitored for 3 years. In 1999, severely burned seedbeds had poor germination, while scorched seedbeds had the highest germination. The reverse was true in 2001. After the first growing season, continued survival of seedlings was greater on severely burned seedbeds for all three cohorts. However, better survival on severely burned seedbeds was not sufficient to overcome poor germination in 1999 and 2000. When using artificial seeding to promote conifer regeneration, we recommend a delay of one full year after a severe spring fire for jack pine and two full years for black spruce and white spruce on boreal aspen and conifer mixedwood sites.

scholarly journals Growth of Coniferous Seedlings on a Drained and Mounded Peatland in Central Alberta

2000 ◽  
Vol 17 (2) ◽  
pp. 71-79 ◽  
Author(s):  
Sam K. Takyi ◽  
Graham R. Hillman
Keyword(s):  
Picea Glauca ◽  
Pinus Contorta ◽  
Black Spruce ◽  
Lodgepole Pine ◽  
White Spruce ◽  
Diameter Growth ◽  
Larix Laricina ◽  
Growing Seasons ◽  
Collar Diameter ◽  
Survival And Growth

Abstract Artificial reforestation experiments compared survival and growth of five species of coniferous containerized seedlings, and seedling browsing by ungulates on a clearcut, drained, and mounded peatland in the boreal forest. Six to seven growing seasons after planting, 91% of all seedlings had survived. Height and diameter growth in five species were ranked as follows: Siberian latch (Larix sibirica Ledeb.) > lodgepole pine (Pinus contorta var. latifolia Engelm.) > tamarack (Larix laricina [Du Roi] K. Koch) > black spruce (Picea mariana [Mill.] B.S.P.) = white spruce(Picea glauca [Moench] Voss). Overall, tamarack height and diameter growth was twice that of either spruce species. Height and diameter growth of tamarack, black spruce, and white spruce planted in the spring was 65% to 97% greater than that of the more robust seedlings for the same species planted in the fall of the same year. Repeated winter browsing by ungulates did not affect survival and growth of the five species. In an experiment where survival and growth of tamarack and black spruce seedlings planted on the mounds were compared with that of seedlings planted on the flat areas between mounds, there were no differences in survival, height, or root collar diameter growth between the two planting sites. In the event that suitable peatlands are used to augment existing timber supplies, lowering the water table through ditching, combined with mound-planting, is a feasible method of reforesting timber-harvested, boreal wet sites with Siberian latch, lodgepole pine, and white spruce. Tamarack and black spruce, however, survive and grow well on drained peatlands without mound-planting. North. J. Appl. For. 17(2):71-79.

The contribution of coarse woody debris to carbon, nitrogen, and phosphorus cycles in three Rocky Mountain coniferous forests

1999 ◽  
Vol 29 (10) ◽  
pp. 1592-1603 ◽  
Author(s):  
Raija Laiho ◽  
Cindy E Prescott
Keyword(s):  
Coarse Woody Debris ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Woody Debris ◽  
Wood Decay ◽  
Rocky Mountain ◽  
Dry Mass ◽  
Ground Vegetation ◽  
Nitrogen And Phosphorus ◽  
Aboveground Litter

The contribution of coarse woody debris to C, N, and P cycles was assessed in forests of lodgepole pine (Pinus contorta Dougl. ex Loud.), white spruce (Picea glauca (Moench Voss), and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) - Engelmann spruce (Picea engelmannii Parry ex Engelm.) in southwestern Alberta. Mass loss and changes in C, N, and P concentrations in decomposing log segments were measured for 14 years. Litter input was measured during 10 years for coarse woody debris, 1 year for ground vegetation, and 5 years for other aboveground litter types. Release of C, N and P from decomposing litter were simulated for a period of 40 years. After 14 years, log segments of pine, spruce, and fir had lost on average 71, 38, and 40%, respectively, of their dry mass. The N content of the pine logs increased, spruce changed little, and fir lost N. Phosphorus accumulated in all logs. The greatest imports of N and P occurred at the pine sites and fir sites, respectively, where these nutrients were the least available, indicating that wood decay organisms may compete with vegetation for limiting nutrients in these forests. Coarse woody debris comprised 3-24% of aboveground litter and contributed less than 5% of the N and P released. Coarse woody debris does not appear to make a significant contribution to N and P cycling in these forests.

Effects of aspen (Populus tremuloides) sucker removal on postfire conifer regeneration in central Alaska

2005 ◽  
Vol 35 (2) ◽  
pp. 483-486 ◽  
Author(s):  
Jill F Johnstone
Keyword(s):  
Seed Germination ◽  
Populus Tremuloides ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Negative Response ◽  
Treatment Results ◽  
Conifer Species ◽  
Canopy Development

This experiment tests the effects of early canopy development by asexually regenerating aspen (Populus tremuloides Michx.) on conifer recruitment after fire in central Alaska. The establishment and growth of three conifer species were observed in response to aboveground removal of aspen suckers for three seasons after burning by wildfire. Of the three species, Pinus contorta Dougl. ex Loud. had the most widespread seed germination and showed the strongest negative response to the presence of the aspen canopy. Picea mariana (Mill.) BSP and Picea glauca (Moench) Voss had low germination and weak or neutral responses to aspen removal. Seedlings of all species accumulated more biomass in the removal treatment. Results from the experiment suggest that competition by aspen early after disturbance can significantly reduce conifer recruitment and growth, an effect that may reinforce the long-term dominance of aspen in asexually regenerating stands.

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