scholarly journals Relationship of spruce budworm (Choristoneura fumiferana) emergence and balsam fir (Abies balsamea) bud flush to climate indices

2009 ◽  
Vol 85 (4) ◽  
pp. 625-630 ◽  
Author(s):  
Alan J Thomson

Temperature records from weather stations across eastern Canada were used with published data on degree-day requirements for spruce budworm larval emergence and balsam fir bud flush to estimate historical patterns of larval emergence and timing of bud flush. The pattern of association was studied using Response Surface Analysis and was found to vary from west to east. April values of the Pacific/North American (PNA) pattern, Pacific Decadal Oscillation (PDO) and Northern Annular Mode (NAM) climate indices showed the most significant relationship to both emergence and bud flush in the 2 Ontario stations, while May values of the PDO and Eastern Pacific (EP) indices were most significant in the 4 Quebec and New Brunswick locations. Key words: phenology, balsam fir, teleconnections

2012 ◽  
Vol 42 (10) ◽  
pp. 1759-1770 ◽  
Author(s):  
C. Eiry Spence ◽  
David A. MacLean

Spruce budworm ( Choristoneura fumiferana (Clemens)) (SBW) outbreaks are a major disturbance that influence stand dynamics and succession in balsam fir ( Abies balsamea (L.) Mill.) dominated forests of eastern Canada. We used stand and regeneration data collected from five plots in each of one immature and five mature stands before, during, and 30 years following the last major SBW outbreak in the Cape Breton Highlands to examine the role of stand and regeneration characteristics in shaping future stand development. Comparisons were also made between regeneration in four SBW outbreak stands versus two SBW salvage stands, with and without a subsequent precommercial thinning, and with 25 plots that underwent SBW emulation harvest. In mature unharvested balsam fir stands, species composition 30 years following the SBW outbreak was closely related to predisturbance species composition, and in immature fir stands, hardwood composition increased from 0% to 4%–27%. Species composition in harvested stands varied depending on whether intolerant hardwoods had been precommercially thinned, where thinned stands had 30% less hardwood 30 years postdisturbance than unthinned stands. Seedling density decreased by 17%–85% from 1979 to 1989 in all SBW outbreak stands, but average seedling height increased by 17%–500% as live canopy cover decreased from an average of 50% to 4%. Results suggest that advanced regeneration should be protected during harvest of balsam fir dominated stands, post-outbreak precommercial thinning will increase tree growth, and live tree retention can help develop late-seral structural characteristics in second-growth stands.


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.


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.


1996 ◽  
Vol 128 (6) ◽  
pp. 1109-1113 ◽  
Author(s):  
Harald Piene

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.


2001 ◽  
Vol 31 (12) ◽  
pp. 2160-2172 ◽  
Author(s):  
Martin Simard ◽  
Serge Payette

Black spruce (Picea mariana (Mill.) BSP) is the dominant tree species of the southernmost (48°N) lichen woodlands in eastern Canada. Most spruce trees in mature lichen woodlands appear to be declining, as shown by the massive invasion of the epiphytic lichen Bryoria on dead branches of dying trees. A dendroecological study was undertaken to identify the main causal factors of the decline. A decline index based on the abundance of Bryoria on spruce trees was used to distinguish healthy from damaged lichen–spruce woodlands and to select sampling sites for tree-ring measurements. Three conifer species (black spruce, balsam fir (Abies balsamea (L.) Mill.), and jack pine (Pinus banksiana Lamb.)) were sampled to compare their growth patterns in time and space. In the late 1970s and mid-1980s, black spruce and balsam fir experienced sharp and synchronous radial-growth reductions, a high frequency of incomplete and missing rings, and mass mortality likely caused by spruce budworm (Choristoneura fumiferana (Clem.)) defoliation. Jack pine, a non-host species, showed no such trend. Because black spruce layers were spared, lichen woodlands will eventually regenerate unless fire occurs in the following years. Black spruce decline can thus be considered as a normal stage in the natural dynamics of the southern lichen woodlands.


2011 ◽  
Vol 41 (5) ◽  
pp. 1112-1120 ◽  
Author(s):  
Sergio Rossi ◽  
Hubert Morin

The renewal of balsam fir (Abies balsamea (L.) P. Mill.) stands is related to the recurrent spruce budworm (Archips fumiferana Clemens [syn.: Choristoneura fumiferana (Clemens)]) outbreaks that favour the growth of the regeneration following death of the dominant trees. The aim of this study was to investigate the population demography and the spatial relationships among individuals in four permanent plots of the boreal forest of Quebec, Canada, after a spruce budworm outbreak. This was realized by collecting data on trees and saplings every five years from 1994 to 2004 and by using Ripley’s K statistics. The younger plots showed recruitment of up to 90 new trees·ha–1·year–1, and mortality following competition among individuals affected up to 27% and 50% of the trees and saplings, respectively. In the plot with the lowest tree density, sapling recruitment was estimated as 378 new individuals·ha–1·year–1. Saplings were aggregated at all spatial scales, whereas trees showed a random pattern of stem distribution. A significant tendency to separation between saplings and trees was observed. The specific stand dynamics observed in balsam fir are connected to an abundant advance regeneration and an age-dependent competition for resources in a heterogeneous environment with different levels of resource availability.


1984 ◽  
Vol 60 (5) ◽  
pp. 273-279 ◽  
Author(s):  
David A. MacLean

Effects of spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks on the productivity and stability of forests in eastern Canada are reviewed and discussed. Defoliation results in reduced growth of trees, widespread tree mortality, and loss of wood production, and thereby causes major forest management problems. At present, the only feasible method for limiting damage and losses from budworm outbreaks over large areas is to apply chemical or biological insecticides periodically to kill larvae and protect the forest from defoliation and tree mortality. Although budworm outbreaks definitely disrupt the wood-producing capacity of forests (or the short-term "stability of forests for human usage"), in terms of overall ecological stability, outbreaks apparently act as a cycling mechanism that allows advance fir-spruce regeneration to succeed the fir-spruce overstory.


1972 ◽  
Vol 104 (7) ◽  
pp. 1051-1054
Author(s):  
J. F. Stewart ◽  
N. R. Brown

AbstractA series of low-volume spray treatments were conducted to study the contact and residual effect of two concentrations of the insecticide phosphamidon to fourth instar spruce budworm, Choristoneura fumiferana (Clem.), on balsam fir, Abies balsamea (L.) Mill, and red spruce, Picea rubens Sarg. Treatment of sprayed larvae on sprayed trees, unsprayed larvae on sprayed trees, and sprayed larvae on unsprayed trees, resulted in two principal conclusions: (a) Higher concentrations of phosphamidon (1% versus 0.5% active) accelerated mortality in all instances and (b) no statistical difference (P = 0.1%) was found in the final mortalities between treatments in which only the foliage was treated and where both larvae and foliage were treated with phosphamidon.


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