Seasonal variations in the uptake of [32P]phosphate ions by excised ectomycorrhizae and lateral roots of Abies balsamea

1984 ◽  
Vol 14 (3) ◽  
pp. 412-415 ◽  
Author(s):  
C. G. Langlois ◽  
J. A. Fortin
Keyword(s):  
Nutrient Solution ◽  
Seasonal Variations ◽  
Lateral Roots ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Phosphate Ions ◽  
Bud Set ◽  
Absorption Potential ◽  
Different Types ◽  
Root Apices

The absorption of phosphate ions by long lateral nonmycorrhizal roots and by four of the most prevalent types of ectomycorrhizae of Abiesbalsamea was followed over one season of growth. For each experiment, the excised roots were bathed for 2.5 h in a buffered nutrient solution containing 100 μg•L−1 of KH2PO4 and 100 μCi•L−1 (1 Ci = 37 GBq) of KH232PO4. The results indicate that the rates of absorption of the different types of balsam fir root apices varied during the season and differed from one type to another. The surface of absorption appeared to have an effect on the amount of phosphate ions taken up from the solution. The rates of absorption measured invitro, seemed to reflect the seasonal absorption potential for phosphate ions by balsam fir roots invivo. It was clearly demonstrated that the most intensive rates of uptake occurred in mid-August immediately after bud set. The possibility that the absorption of phosphate ions is controlled by internal demand and is related to the translocation of carbohydrates is discussed.

Shedding of ephemeral roots in gymnosperms

1982 ◽  
Vol 60 (11) ◽  
pp. 2295-2302 ◽  
Author(s):  
Joanna T. Tippett
Keyword(s):  
Lateral Roots ◽  
Abies Balsamea ◽  
Protective Layer ◽  
Pinus Strobus ◽  
Tsuga Canadensis ◽  
Balsam Fir ◽  
Tissue Formation ◽  
White Pine ◽  
Vascular Tissues ◽  
Periderm Formation

Periderm formation across the base of short lateral roots facilitated their shedding in balsam fir (Abies balsamea (L.) Mill.), white pine (Pinus strobus L.), and hemlock (Tsuga canadensis (L.) Carr.). The periderm originated either from the pericycle, in line with normal subendodermal development, or after dedifferentiation and redifferentiation of cells across existing vascular tissues near the base of senescent short roots. Consequently the short roots were either shed neatly along with the cortex of the parent roots or they were isolated by a new layer of periderm linking existing parent-root periderm, analogous to protective tissue formation beneath petiole abscission zones. Short roots were not always isolated by periderm prior to detachment, but periderm still formed at the base of the root stubs and eventually became the superficial protective layer of the root scars.

scholarly journals Shoot and Bud Development in Balsam Fir: Implications for Pruning of Christmas Trees

1982 ◽  
Vol 58 (4) ◽  
pp. 168-172 ◽  
Author(s):  
G. R. Powell
Keyword(s):  
Abies Balsamea ◽  
Active Phase ◽  
Shoot Elongation ◽  
Shoot Development ◽  
Balsam Fir ◽  
Significant Response ◽  
Bud Development ◽  
Christmas Trees ◽  
Different Types

The processes of development of shoots and buds of balsam fir (Abies balsamea (L.) Mill.) and the positions of buds of different types and with differing degrees of development, are described as a basis for understanding what happens in response to pruning of portions of shoots (shearing) at different times of year. The greatest response in shoot and bud development will result from pruning in late July and early August. Degree of response will decrease with advancing time of pruning from August to October. Pruning from late March to early May will produce less, bud significant response in subsequent bud development but little in first-season shoot development. Pruning from November to March can be as effective as pruning in late March and early April, but risks of damage are greater. Pruning in the most active phase of shoot elongation (June to mid-July) is not advisable.

Weather and Outbreaks of the Spruce Budworm in the Province of Quebec from 1939 to 1956

1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
The Past ◽  
Forest Regions ◽  
Tree Component ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Nearly all forest regions in the Province of Quebec where balsam fir (Abies balsamea (L.) Mill.) is an important tree component have been subjected to severe defoliation by the spruce budworm, Choristoneura fumiferana (Clem.), during the past 20 years. These outbreaks have followed an easterly direction beginning near the Ontario-Quebec border in 1939 and ending in the Gaspé Peninsula in 1958.

scholarly journals Mixed Regional Shifts in Conifer Productivity under 21st-Century Climate Projections in Canada’s Northeastern Boreal Forest

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 248
Author(s):  
Tyler Searls ◽  
James Steenberg ◽  
Xinbiao Zhu ◽  
Charles P.-A. Bourque ◽  
Fan-Rui Meng
Keyword(s):  
Climate Change ◽  
Model Validation ◽  
21St Century ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Acer Rubrum ◽  
Forest Growth ◽  
Balsam Fir ◽  
Growth And Yield ◽  
Climate Projections

Models of forest growth and yield (G&Y) are a key component in long-term strategic forest management plans. Models leveraging the industry-standard “empirical” approach to G&Y are frequently underpinned by an assumption of historical consistency in climatic growing conditions. This assumption is problematic as forest managers look to obtain reliable growth predictions under the changing climate of the 21st century. Consequently, there is a pressing need for G&Y modelling approaches that can be more robustly applied under the influence of climate change. In this study we utilized an established forest gap model (JABOWA-3) to simulate G&Y between 2020 and 2100 under Representative Concentration Pathways (RCP) 2.6, 4.5, and 8.5 in the Canadian province of Newfoundland and Labrador (NL). Simulations were completed using the province’s permanent sample plot data and surface-fitted climatic datasets. Through model validation, we found simulated basal area (BA) aligned with observed BA for the major conifer species components of NL’s forests, including black spruce [Picea mariana (Mill.) Britton et al.] and balsam fir [Abies balsamea (L.) Mill]. Model validation was not as robust for the less abundant species components of NL (e.g., Acer rubrum L. 1753, Populus tremuloides Michx., and Picea glauca (Moench) Voss). Our simulations generally indicate that projected climatic changes may modestly increase black spruce and balsam fir productivity in the more northerly growing environments within NL. In contrast, we found productivity of these same species to only be maintained, and in some instances even decline, toward NL’s southerly extents. These generalizations are moderated by species, RCP, and geographic parameters. Growth modifiers were also prepared to render empirical G&Y projections more robust for use under periods of climate change.

Prescribed Burning for Stand Conversion in Budworm-killed Balsam Fir: An Ontario Case History

1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae
Keyword(s):  
Fuel Consumption ◽  
Prescribed Burning ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Fire Spread ◽  
Fire Effects ◽  
Balsam Fir ◽  
Prescribed Burn ◽  
Stand Conversion

Recent spruce budworm (Choristoneura fumiferana [Clem.]) infestations have resulted in widespread areas of balsam fir (Abies balsamea [L.] Mill.) mortality in Ontario, and there is growing interest in reestablishing these areas quickly as productive forests. One technique being used is prescribed fire after a salvage and bulldozer tramping operation. A 445-ha prescribed burn was carried out under moderate fire danger conditions in northern Ontario. The site, which was covered by balsam fir fuel that had been killed by spruce budworm, was tramped to improve fire spread. Weather, fuel consumption, and fire effects are reported. The burn effectively reduced heavy surface fuel loadings and consequently planting on the site was easier. Key words: Prescribed burning, fire, spruce budworm. Choristoneura fumiferana, balsam fir, Abies balsamea, fuel consumption, site preparation, tramping, stand conversion.

LONG TERM STUDY OF THE EFFECTIVENESS OF AERIAL APPLICATION OF BACILLUS THURINGIENSIS – ACEPHATE COMBINATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1977 ◽  
Vol 109 (9) ◽  
pp. 1239-1248 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Population Densities ◽  
Long Term Study

AbstractBacillus thuringiensis (Dipel® 36B) mixed with a sublethal concentration of acephate (Orthene®) (O, S-dimethyl acetylphosphoramidothioate), an organophosphorous insecticide, was applied at 2.35–14 l./ha to white spruce (Picea glauca) and balsam fir (Abies balsamea) trees infested with spruce budworm, Choristoneura fumiferana (Clem.). The treatment rate was 20 Billion International Units of B. thuringiensis (B.t.) activity with or without 42 g of active ingredient of acephate/ha.The ground deposit of the standard Dipel wettable powder formulation was 12% of emitted volume compared with 21–32% for the Dipel 36B flowable. The viability of B.t. spores was drastically reduced after 1 day of weathering but a high level of biological activity by the spore–crystal complex persisted for up to 20 days post-spray due probably to crystal activity.The addition of about 10% of the recommended operational rate of acephate to the B.t. suspension increased larval mortality by 34% when applied at 4.7 l./ha. Reductions in budworm populations were 97–99% in B.t. + acephate plots and 86–90% in B.t. alone plots.Plots with moderate budworm densities of up to 27 larvae/100 buds on white spruce and 36/100 on balsam fir were satisfactorily protected from excessive defoliation in the year of spray by B.t. with or without acephate. Plots with higher population densities were not satisfactorily protected based on the branch sample examination but aerial color photographs indicated good protection to the top third of the trees. Population declines were greater and defoliation and oviposition were lower in the treated plots than in the untreated checks 1 year later without further treatment. Two years later the larval population densities in all plots were low but the density was twice as high in the untreated check as in the treated plots, indicating long term suppression by the treatments. Defoliation was negligible in all plots.The treatments had no deleterious effect on spruce budworm parasitism. The data indicate that the integrated approach using Bacillus thuringiensis – chemical pesticide combinations is a viable alternative to the use of chemical pesticides alone in spruce budworm control. Large scale testing is now warranted.

CHANGES IN SPRUCE BUDWORM DEFOLIATION WITH CROWN LEVEL

1996 ◽  
Vol 128 (6) ◽  
pp. 1109-1113 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Nova Scotia ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Cost Effective ◽  
Balsam Fir ◽  
Crown Length ◽  
Cape Breton ◽  
Cost Effective Approach ◽  
The Common

AbstractDetailed estimates of defoliation caused by spruce budworm [Choristoneura fumiferana (Clem.)] over the crown length of young balsam fir [Abies balsamea (L.) Mill.] were made throughout a spruce budworm outbreak from 1976 to 1984 in the Cape Breton Highlands, Nova Scotia. The results show no clear tendency for a particular level of the crown to be damaged more heavily than any other. Thus, there is no reason to continue the common practice of taking samples from the mid-crown level on the assumption that they represent an ‘average’ level of defoliation either for high or low populations. Sampling from the bottom of the crown should provide a more convenient and cost-effective approach for estimating defoliation.

Incidence and impact of Entomophaga aulicae (Zygomycetes: Entomophthorales) and a nucleopolyhedrovirus in an outbreak of the whitemarked tussock moth (Lepidoptera: Lymantriidae)

2002 ◽  
Vol 134 (6) ◽  
pp. 825-845 ◽  
Author(s):  
K. van Frankenhuyzen ◽  
P. Ebling ◽  
G. Thurston ◽  
C. Lucarotti ◽  
T. Royama ◽  
...  
Keyword(s):  
Mass Density ◽  
Abies Balsamea ◽  
Larval Survival ◽  
Balsam Fir ◽  
Egg Mass ◽  
Population Changes ◽  
Tussock Moth ◽  
Orgyia Leucostigma ◽  
Recent Outbreak ◽  
Whitemarked Tussock Moth

AbstractIn Nova Scotia, the whitemarked tussock moth, Orgyia leucostigma Fitch, periodically erupts in outbreaks that typically last 3–5 years. Population changes during a recent outbreak were monitored by means of aerial defoliation surveys and fall egg-mass surveys that were conducted between 1997 and 2001. Severe defoliation was first recorded on approximately 250 ha in 1996. The defoliated area increased rapidly to hundreds of thousands hectares in 1998, after which it sharply declined to about 4700 ha in 2000 and 0 ha in 2001. The total infested area [>0.01 egg masses per three branches of Abies balsamea L. (Pinaceae)] decreased from about 1.4 million ha in 1997 to about 13 500 ha in 2001. Between 1996 and 2001, the infestation involved a cumulative total of 2.4 million ha, covering most of the province. The collapse of larval populations during 1998 was associated with widespread prevalence of a singly embedded nucleopolyhedrovirus (NPV) and Entomophaga aulicae (Reichardt in Bail) Humber (Zygomycetes: Entomophthorales). Sampling of larval populations in late July and August 1998 revealed a widespread and virtually sympatric occurrence of those pathogens in areas that were under defoliation pressure, with infection levels by each pathogen exceeding 75% in many sample sites. Pathogen impacts on larval survival were studied in 1999 in a persisting pocket of severe infestation in Hants County. Larvae were collected every 3 d from balsam fir branch samples between 17 June and 21 July and reared to determine cause of death. The two pathogens together accounted for at least 50% of cohort mortality, calculated as marginal mortality rates according to Royama (2001). Although cohort mortality due to disease on balsam fir was significantly correlated with between-generation reduction in mean egg-mass density, overall pathogen-induced mortality was not high enough to drive the populations into an endemic state, and a moderate infestation persisted into 2000.

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