Trends in forest depletion, seed supply, and reforestation in Canada during the past four decades

2001 ◽  
Vol 77 (6) ◽  
pp. 1014-1021 ◽  
Author(s):  
E. K. Morgenstern ◽  
B. S. P. Wang
Keyword(s):  
British Columbia ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Pinus Contorta ◽  
Maritime Provinces ◽  
Seed Orchards ◽  
Seed Collection ◽  
Seed Supply ◽  
Forest Depletion ◽  
Broadleaf Species

Progress in reforestation is reviewed and the results of a 1999 survey of seed collection and utilization are presented. The review includes forest depletion, regeneration and seed supply for Canada for the 1960–99 period. Depletion of stocked, timber-productive land has increased from less than 2 million ha annually to just under 2.5 million ha, primarily due to an increase in harvesting from about 800 000 ha to slightly over 1 million ha in recent years, and also due to larger fires during the last decade. The depleted area amounts to 1% of the total commercial forest. Natural regeneration consistently covered more than 60% of the depleted area. Artificial regeneration (seeding and planting) has increased dramatically from 86 000 ha per year in 1965 to 513 000 ha in 1990, and has since levelled off at about 460 000 ha. The seed supply situation has also improved greatly, primarily due to tree improvement that resulted in the establishment of seed orchards, which were expanded from 364 ha in 1981 to 3008 ha in 1995. New analytical biochemical methods suggest that in orchard seed, genetic variation and diversity are maintained.The seed survey, including 36 conifer and 29 broadleaf species, indicated that 2.5 billion seeds were collected in 1999 (which was not a good seed year) and 3.9 billion seeds were sown. These 3.9 billion seeds appear to be sufficient to again restock approximately 460 000 ha per year, i.e., the same area as regenerated annually in the 1995–99 period. Improved seed treatment and sowing methods appear to have made seedling production substantially more efficient during the last 20 years. The major species sown in 1999 were: Picea mariana (35%), Picea glauca (22%), Pinus contorta (13%), and Pinus banksiana (12%). For Canada as a whole, 25% of the seed came from seed orchards, but for the Maritime Provinces, Québec, and Manitoba this percentage ranged from 60 to 90%. Orchard production is still growing: British Columbia and Québec will produce 80% of their planting stock from it during the next decade, and New Brunswick and British Columbia are already harvesting seed from second-generation orchards. It is expected that the high quality of seed obtained from seed orchards will contribute significantly to the efficiency of the reforestation program and increase the value of future forests. Key words: forest depletion, reforestation, seed orchards, seed supply

Morphological indicators of growth response of coniferous advance regeneration to overstorey removal in the boreal forest

2000 ◽  
Vol 76 (4) ◽  
pp. 633-642 ◽  
Author(s):  
Jean-Claude Ruel ◽  
Christian Messier ◽  
Yves Claveau ◽  
René Doucet ◽  
Phil Comeau
Keyword(s):  
Picea Glauca ◽  
Pinus Banksiana ◽  
Pinus Contorta ◽  
Sudden Change ◽  
Abies Balsamea ◽  
Critical Threshold ◽  
Species Number ◽  
Advance Regeneration ◽  
Tolerant Species ◽  
Shade Tolerant Species

Regeneration of forest stands through the preservation of existing advance regeneration has gained considerable interest in various regions of North America. The effectiveness of this approach relies on the capacity of regeneration to respond positively to overstory removal. Responses of advance regeneration to release is dependent on tree characteristics and site conditions interacting with the degree of physiological shock caused by the sudden change in environmental conditions. This paper presents a review of the literature describing the relationships between morphological indicators and the advance regeneration response to canopy removal. It focuses primarily on the following species: jack pine (Pinus banksiana Lamb.), lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.), black spruce (Picea mariana (Mill.) B.S.P.), interior spruce (Picea glauca × engelmannii), white spruce (Picea glauca (Moench) Voss), balsam fir (Abies balsamea (L.) Mill.), and subalpine fir (Abies lasiocarpa (Hook.) Nutt). Pre-release height growth has been found to be a good indicator of post-release response for many species. Live-crown ratio also appears to be a good indicator of vigour for shade-tolerant species. The ratio of leader length to length of the longest lateral at the last whorl could serve to describe the degree of suppression before harvest for shade-tolerant species. Number of nodal and internodal branches or buds has been found to be related with vigour for many species. Logging damage has been shown to be an important determinant of seedling response to overstory removal. In contrast, height/diameter ratio has limited value for predicting response to release since it varies with site, species and other factors. No clear relationship between age, height at release and response to release could be demonstrated. This paper also suggests the use of combined indicators and critical threshold values for these indicators. Key words: advance regeneration, careful logging, vigour, clearcutting

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.

Pissodes terminalis. [Distribution map].

2006 ◽  
Author(s):  
Keyword(s):  
British Columbia ◽  
North America ◽  
South Dakota ◽  
Northwest Territories ◽  
Geographical Distribution ◽  
Pinus Banksiana ◽  
Pinus Contorta ◽  
Jack Pine ◽  
Distribution Map ◽  
New Distribution

Abstract A new distribution map is provided for Pissodes terminalis Hopping. Coleoptera: Curculionidae. Hosts: Jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta). Information is given on the geographical distribution in North America (Canada, Alberta, British Columbia, Manitoba, Northwest Territories, Saskatchewan, Yukon, USA, California, Colorado, Idaho, Montana, Oregon, South Dakota, Washington, Wyoming).

Spruce growth response specificity after treatment with plant growth-promoting Pseudomonads

1999 ◽  
Vol 77 (1) ◽  
pp. 22-31 ◽  
Author(s):  
Masahiro Shishido ◽  
Christopher P Chanway
Keyword(s):  
British Columbia ◽  
Plant Growth ◽  
Seedling Growth ◽  
Picea Glauca ◽  
Forest Floor ◽  
Growth Promotion ◽  
Geographical Area ◽  
Seed Collection ◽  
Plant Growth Promoting ◽  
Growth Promoting

Naturally regenerating hybrid spruce seedlings (Picea glauca (Moench) Voss beta Picea engelmannii Parry) were collected from sites near Mackenzie, Salmon Arm, and Williams Lake, British Columbia, Canada. Bacteria were isolated from roots and screened in greenhouse trials for their ability to enhance spruce growth. Three strains belonging to the genus Pseudomonas were selected for study based on their disparate geographic origins and their capacity to consistently stimulate spruce seedling growth in screening trials. Factorial experiments were performed in the greenhouse to evaluate the effectiveness of these Pseudomonas strains with different spruce ecotypes. Factors tested were spruce seed sources, Pseudomonas isolates, and forest floor soils originating from different sites. Three levels of each factor were studied: one spruce seedlot, one Pseudomonas isolate, and one forest floor type each originated from a site at Mackenzie, Salmon Arm, and Williams Lake, British Columbia. Fourteen weeks after treatments were established, spruce biomass accumulation was greatest when spruce ecotypes were inoculated with bacteria originating from the same geographical area as spruce seed. However, Pseudomonas strains originating from sites other than the seed collection area also stimulated seedling growth significantly, rendering the difference in growth promotion between bacterial treatments small and insignificant. In addition, spruce growth promotion was not enhanced when seed was treated with combinations of Pseudomonas strains and forest floor soils originating from the same forest ecosystem. We conclude that specificity between spruce ecotypes and plant growth-promoting rhizobacteria strains can be detected under carefully controlled conditions, thereby supporting the hypothesis that growth-promoting bacteria may adapt to their plant hosts. However, the growth advantage accruing to seedlings treated with bacteria originating from the same ecosystem is small and suggests that it is not necessary to match Pseudomonas strains with spruce ecotypes and soil types for effective seedling growth promotion.Key words: Pseudomonas, spruce, specificity, growth promotion.

Growth and crown morphological responses of boreal conifer seedlings and saplings with contrasting shade tolerance to a gradient of light and height

2002 ◽  
Vol 32 (3) ◽  
pp. 458-468 ◽  
Author(s):  
Yves Claveau ◽  
Christian Messier ◽  
Philip G Comeau ◽  
K Dave Coates
Keyword(s):  
Picea Glauca ◽  
Pinus Banksiana ◽  
Pinus Contorta ◽  
Morphological Changes ◽  
Abies Balsamea ◽  
Tree Height ◽  
Light Level ◽  
Abies Lasiocarpa ◽  
Morphological Responses ◽  
Picea Species

The effects of gradients in light levels and tree height on growth and crown attributes of six conifer species were studied in eastern and western Canada. Three conifers were studied in British Columbia (Abies lasiocarpa (Hook.) Nutt., Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm., and Pinus contorta Dougl. ex Loud. var. latifolia Engelm.), and three in Quebec (Abies balsamea (L.) Mill., Picea glauca, and Pinus banksiana Lamb.). For several growth and morphological parameters, conifers reacted strongly to both an increase in light and tree height. Significant or nearly significant interactions between light classes and height were found for height and diameter growth of most species as well as for many crown attributes for both Abies and Picea. These interactions usually indicated that growth or morphological changes occurred with increasing height from a certain light level. Within a single genus, both eastern and western tree species showed the same overall acclimation to light and height. As generally reported, Pinus species showed less variation in growth and morphological responses to light than Abies and Picea species.

Comparisons of genetic diversity in white spruce (Picea glauca) and jack pine (Pinus banksiana) seed orchards with natural populations

2001 ◽  
Vol 31 (6) ◽  
pp. 943-949 ◽  
Author(s):  
M J.W Godt ◽  
J L Hamrick ◽  
M A Edwards-Burke ◽  
J H Williams
Keyword(s):  
Genetic Diversity ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Gene Diversity ◽  
Natural Populations ◽  
Source Area ◽  
White Spruce ◽  
Seed Orchard ◽  
Jack Pine ◽  
Seed Orchards

Genetic diversity within a white spruce (Picea glauca (Moench) Voss) seed orchard (consisting of 40 clones) and a jack pine (Pinus banksiana Lamb.) seed orchard (31 clones) was assessed and compared with genetic diversity in natural populations within the source area for the orchards. Genetic diversity was determined at 18 allozyme loci for seven white spruce populations and 27 loci for five jack pine populations, and the two orchards. Gene diversity maintained within the seed orchards (He = 0.157 for white spruce and 0.114 for jack pine) was similar to that found within the source area for each species (He = 0.164 and 0.114 for white spruce and jack pine, respectively). However, nine white spruce alleles and 12 jack pine alleles identified in the source area were not present in the seed orchards. These alleles occurred at low frequencies in the natural populations (mean frequency = 0.023 and 0.014 for white spruce and jack pine, respectively). Mean genetic identities between the seed orchards and their natural populations were high (>0.99), indicating that common allele occurrences and frequencies were similar between the orchards and their source area. One allele in the white spruce orchard and two in the jack pine seed orchard did not occur within the natural population samples. Simulations indicated that randomly reducing the number of clones within the seed orchards would decrease allelic richness slightly but would have little effect on overall gene diversity.

Fungi that cause sapstain in Canadian softwoods

1999 ◽  
Vol 45 (11) ◽  
pp. 914-922 ◽  
Author(s):  
A Uzunovic ◽  
D -Q Yang ◽  
P Gagné ◽  
C Breuil ◽  
L Bernier ◽  
...  
Keyword(s):  
Picea Mariana ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Pinus Contorta ◽  
Abies Balsamea ◽  
Forest Products ◽  
Fungal Species ◽  
Forest Products Industry ◽  
Diverse Range ◽  
Commercially Important

The Canadian forest products industry suffers considerable losses due to discoloration caused by sapstain fungi. Although studied for a number of years, the identity, biology, and ecology of these fungi are still only partly understood. To determine which fungi caused stain problems, a detailed survey was conducted at seven selected sawmills across Canada. In summer 1997, fresh logs and lumber were set aside in the mills 1 month prior to sampling for fungi. We excluded bark-beetle-attacked wood and our logs remained free from their attack during storage. Five commercially important softwood species, Abies balsamea (L.) Mill., Picea mariana (Mill.) B.S.P., Picea glauca (Moench) Voss, Pinus contorta Dougl., and Pinus banksiana Lamb., were included in the studies. A total of 1863 isolates were isolated from stained and adjacent areas on test wood, and were identified based on their morphological and physiological characteristics and mating compatibility to 13 different species representing five genera. The most commonly encountered genus, Ophiostoma (97%), was represented by nine species. A more diverse range of fungi was found in logs than in lumber; some species were more frequently isolated from one type of substrate and rarely (or not at all) from the other. No fungal species occurred exclusively in a particular region or wood substrate.Key words: bluestain, lumber, logs, Ophiostoma, Ceratocystis.

Tamarack (Pinaceae): previously unrecorded developmental host for pine engraver and southern pine engraver (Coleoptera: Scolytidae)

2002 ◽  
Vol 134 (3) ◽  
pp. 299-302 ◽  
Author(s):  
Kamal J.K. Gandhi ◽  
Steven J. Seybold
Keyword(s):  
North America ◽  
Pinus Ponderosa ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Pinus Contorta ◽  
Ips Pini ◽  
Usda Forest Service ◽  
Pine Engraver ◽  
Adult Insect ◽  
Pinus Coulteri

The pine engraver, Ips pini (Say), is broadly distributed across North America (Lanier 1972; Wood 1982; Seybold et al. 1995) with a host range that includes most species of Pinus L., and in rare cases, species of Picea A. Dietrich (both Pinaceae), within its range (Swaine 1918; Bright 1976; Wood 1982; Furniss and Carolin 1992). Ips pini has been recorded from Pinus banksiana Lamb., Pinus resinosa Ait., and Pinus strobus L. (eastern North America), and from three of four subspecies of Pinus contorta Dougl. ex Loudon [P. c. contorta, P. c. latifolia (Engelm.) Critch., and P. c. murrayana (Balf.) Critch.], Pinus coulteri D. Don, Pinus jeffreyi Balf., Pinus ponderosa Dougl. ex P. and C. Laws., and Pinus flexilis James (western North America) (Furniss and Carolin 1992; Seybold et al. 1995). Hopping (1964) reported I. pini on Picea rubens Sarg., Picea glauca (Moench) Voss, and Picea engelmannii Parry ex Engelm. The adult insect is intermediate in length relative to most Ips spp., ranging from 3.3 to 4.5 mm (Hopping 1964; Bright 1976; Wood 1982; USDA Forest Service 1985).

Feeding by Leptoglossus occidentalis (Hemiptera: Coreidae) reduces seed set in lodgepole pine (Pinaceae)

2001 ◽  
Vol 133 (6) ◽  
pp. 857-865 ◽  
Author(s):  
Ward B. Strong ◽  
Sarah L. Bates ◽  
Michael U. Stoehr
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Seed Set ◽  
Lodgepole Pine ◽  
Seed Orchards ◽  
Leptoglossus Occidentalis ◽  
Insect Exclusion ◽  
Filled Seeds ◽  
Water Treated Control

AbstractLow seed set is a serious problem in seed orchards of lodgepole pine (Pinus contorta var. latifolia Engelmann) in the southern interior of British Columbia. We tested the hypothesis that Leptoglossus occidentalis Heidemann is responsible for the low seed set. Cones enclosed in insect exclusion bags as part of a pollination experiment produced significantly more filled seeds per cone than cones that were not bagged. In a separate bagging experiment, cones that were enclosed with a L. occidentalis female and her progeny produced only about one filled seed per cone, compared with about 28 seeds in bagged control cones. Changes in microclimate associated with the use of bags did not appear to be responsible for the observed increase in seed set in bagged cones. Leptoglossus occidentalis was also excluded from trees using the insecticide fenvalerate. Cones on fenvalerate-treated trees produced > 11 filled seeds per cone, whereas water-treated (control) cones produced < 1.7 filled seeds. These data suggest that L. occidentalis should be considered a serious pest in lodgepole pine seed orchards.

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