Genomic variability in the vascular cambium of Abies balsamea

1989 ◽  
Vol 67 (4) ◽  
pp. 990-996 ◽  
Author(s):  
E. J. Mellerowicz ◽  
R. T. Riding ◽  
C. H. A. Little

DNA content was measured cytophotometrically in Feulgen-stained nuclei of fusiform cambial initials from 1- (twig) and 19-year-old (stem base) cambia of balsam fir (Abies balsamea) trees throughout the season. Telophase (2C) and prophase (4C) DNA contents varied with both cambial age and time of year. Maximum DNA contents were observed at the beginning of cambial activity in April. They were lower in the 1-year-old cambium (42.3 (2C) and 84.3 (4C) pg DNA) than in the 19-year-old cambium (59.4 (2C) and 111.1 (4C) pg DNA). The DNA levels decreased during the cambial growing season, attaining minimal values in September of 28.3 (2C) and 53.5 (4C) pg and 37.9 (2C) and 74.5 (4C) pg in the 1- and 19-year-old cambia, respectively. In the autumn, cells accumulated in the G1 phase of the cell cycle. DNA synthesis then took place increasing the 2C levels from the minimum values to the maximum values. This DNA synthesis in 1-year-old cambia started before the beginning of the transition from the resting to the quiescent stage of dormancy.

1970 ◽  
Vol 48 (6) ◽  
pp. 1027-1028 ◽  
Author(s):  
C. H. A. Little ◽  
D. C. Eidt

Using an antitranspirant (abscisic acid) and a transpiration promoter (Floralife), a positive correlation was found between the rates of transpiration and cambial activity in cuttings of balsam fir, Abies balsamea (L.) Mill. Differences in transpiration rate were not due to differences in xylem production.


1963 ◽  
Vol 39 (3) ◽  
pp. 318-321
Author(s):  
J. D. Gagnon

Radial increments of 38 balsam fir trees (Abies balsamea (L.) Mill.) differing in height, crown class and vigour, were studied to determine if their correlation with the McLintock classification was better than that with either total height, crown class, vigour class or crown ratio. Measurements at weekly intervals during the 1961 growing season have shown the superiority of the McLintock tree classification over the other four. It seems, therefore, that the interaction of the factors involved in McLintock classification is essentially valid even for very short predictions.


1974 ◽  
Vol 52 (7) ◽  
pp. 1723-1730 ◽  
Author(s):  
C. H. A. Little ◽  
J. M. Bonga

Cuttings were collected from the field between September and May, when buds and cambia are dormant, and were placed under favorable conditions in environmental cabinets. Radial width of new xylem, measured at the midpoint of the cuttings, was used to indicate cambial activity.In bud-bearing cuttings, cambial activity was associated with bud activity. Debudding decreased cambial growth. Application of a mixture of indole-3-acetic acid (IAA) and lanolin to the apex of debudded cuttings promoted cambial activity in a manner similar to that effected by expanding buds. Clearly, bud-produced auxin is required for cambial activity in balsam fir.Cambial activity increased with increasing preexposure to natural chilling until about December; thereafter additional preexposure did not further increase cambial growth. Extending the natural chilling period with a period of artificial chilling enhanced cambial growth in material collected during the autumn, but not in material collected later. The effect of chilling was manifested whether or not buds were present during the chilling period. Long photoperiod partly compensated for lack of chilling in autumn-collected material. It is concluded that the cambium of balsam fir in central New Brunswick has an autumnal rest period that grades into quiescence by about December. Cambial rest was not broken by applications of IAA, gibberellic acid, or kinetin, or by IAA with either of the others.


1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais

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.


1975 ◽  
Vol 53 (24) ◽  
pp. 3041-3050 ◽  
Author(s):  
C. H. A. Little

In experiments with attached and detached shoots of balsam fir, Abies balsamea L., synthetic (±)abscisic acid (ABA) (1) reduced photosynthesis and transpiration by inducing stomatal closure, (2) inhibited indoleacetic acid (IAA) - induced cambial activity in photosynthesizing and non-photosynthesizing shoots, and (3) inhibited the basipetal movement of [14C]IAA. Neither gibberellic acid nor kinetin counteracted the inhibitory effect of (±)ABA on IAA-induced cambial activity. In addition it was demonstrated that increasing the internal water stress increased the level of endogenous ABA in the phloem–cambial region of bark peelings and decreased the basipetal movement of [14C]IAA through branch sections. On the basis of these findings it is proposed that internal water stress inhibits cambial activity, partly through increasing the level of ABA; the ABA acts to decrease the provision of carbohydrates and auxin that are required for cambial growth.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 248
Author(s):  
Tyler Searls ◽  
James Steenberg ◽  
Xinbiao Zhu ◽  
Charles P.-A. Bourque ◽  
Fan-Rui Meng

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.


1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae

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.


1977 ◽  
Vol 109 (9) ◽  
pp. 1239-1248 ◽  
Author(s):  
O. N. Morris

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.


IAWA Journal ◽  
2015 ◽  
Vol 36 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Yawen Zheng ◽  
Biao Pan ◽  
Takao Itohl

The effect of ethephon (Et) and methyl jasmonate (MeJA) on the induction of traumatic gum ducts (TGDs) was studied in Chinese sweetgum, Liquidambar formosana, a broad-leaved tree species. Lanolin pastes with concentrations of 1, 2 and 5% (w/w) of these chemicals were applied to the intact bark of the trees in May, July and September without any wounding. The trees did not show any response to the treatment of MeJA, but TGDs were formed in response to treatment with Et. Trees treated with Et in the active growing season (May) produced more rows of TGDs than those treated in July or September, suggesting a strong relationship between cambial activity and susceptibility to TGD induction. These results are discussed in comparison with responses of conifers and some angiosperms to MeJA and Et treatments with and without associated wounding reported in the literature.


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