Reduction of black spruce seed bank by spruce budworm infestation compromises postfire stand regeneration

2005 ◽  
Vol 35 (7) ◽  
pp. 1686-1696 ◽  
Author(s):  
Martin Simard ◽  
Serge Payette
Keyword(s):  
Seed Bank ◽  
Black Spruce ◽  
Reproductive Potential ◽  
Basal Area ◽  
Spruce Budworm ◽  
Stand Age ◽  
Viable Seed ◽  
Eastern Canada ◽  
Postfire Regeneration ◽  
Fire Disturbances

In the southern boreal forest of eastern Canada, black spruce (Picea mariana (Mill.) BSP) is subjected to both defoliating insect and fire disturbances. As black spruce depends on its aerial seed bank for postfire regeneration, reduction of cone crop during a spruce budworm (Choristoneura fumiferana (Clem.)) outbreak opens a vulnerability window during which stand regeneration could be hindered in the event of a fire. To assess the long-term effect of spruce budworm outbreak on black spruce reproductive potential, cone production and viable seed bank were estimated using cone crop surveys and germination trials in black spruce – lichen woodland stands that sustained different levels of defoliation during the 1980s. Black spruce cone crop was significantly related to the defoliation history of the stands (R2 = 0.89), but not to stand age, basal area, or tree density. Black spruce stands damaged by severe defoliation showed a smaller number of cones, a higher incidence of insect-damaged cones, and a viable seed bank 3 to 17 times smaller than a lightly defoliated stand. The vulnerability window for black spruce regeneration following a spruce budworm outbreak may be as long as 20 years in the study area because black spruce seed bank in heavily defoliated stands has not yet replenished. Our work supports conclusions from stand reconstruction studies that suggest closed-crown spruce–moss stands convert to open lichen woodlands as a result of weak postfire regeneration caused by successive insect and fire disturbances.

The influence of forest composition and climate on outbreak characteristics of the spruce budworm in eastern Canada

2013 ◽  
Vol 43 (12) ◽  
pp. 1181-1195 ◽  
Author(s):  
David R. Gray
Keyword(s):  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Basal Area ◽  
Spruce Budworm ◽  
Climate Scenario ◽  
Forest Composition ◽  
Eastern Canada ◽  
The North ◽  
Average Change ◽  
Maximum Temperatures

The spruce budworm (Choristoneura fumiferana Clemens) is perhaps the single most important disturbance agent in Canada’s eastern forests. Climate and forest composition are dominant factors in spruce budworm outbreak dynamics through their direct influences on the pest, its natural enemies, and its hosts, and through their influence on the multitrophic interactions that are important in outbreak dynamics. A combination of four climate variables, three forest composition variables, and one location variable explained 60% of the multivariate variability in outbreak characteristics (duration and severity) in eastern Canada. Outbreak duration was most strongly influenced by April–May accumulation of degree-days; outbreak severity was most strongly influenced by the extreme maximum temperatures of April–May. The basal area of balsam fir had a stronger influence than that of black spruce on duration and on severity. Both outbreak characteristics declined in more northerly locations. Under a projected future (2011–2040) climate scenario the largest increases in outbreak duration and severity are predicted to occur on the Gaspé Peninsula and the north shore of the St. Lawrence River (Quebec). The largest decreases in duration and severity are predicted to occur in southern Ontario and along the Bay of Fundy in New Brunswick and Nova Scotia. The predicted average change in outbreak duration is around –1.3 years. The predicted average change in outbreak severity is only slightly different from zero (around –1.5% defoliation).

scholarly journals The Difficulty of Predicting Eastern Spruce Dwarf Mistletoe in Lowland Black Spruce: Model Benchmarking in Northern Minnesota, USA

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Ella R. Gray ◽  
Matthew B. Russell ◽  
Marcella A. Windmuller-Campione
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Forest Health ◽  
Basal Area ◽  
Predictive Performance ◽  
Stand Age ◽  
Management Decisions ◽  
Dwarf Mistletoe ◽  
Growing Seasons ◽  
Model Interpretation

Insects, fungi, and diseases play an important role in forest stand development and subsequently, forest management decisions and treatments. As these disturbance agents commonly occur within and across landscapes, modeling has often been used to inform forest planning and management decisions. However, models are rarely benchmarked, leaving questions about their utility. Here, we assessed the predictive performance of a Bayesian hierarchical model through on–the-ground sampling to explore what features of stand structure or composition may be important factors related to eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck) presence in lowland black spruce (Picea mariana (Mill.) B. S. P.). Twenty-five state-owned stands included in the predictive model were sampled during the 2019 and 2020 growing seasons. Within each stand, data related to the presence of eastern spruce dwarf mistletoe, stand structure, and species composition were collected. The model accurately predicted eastern spruce dwarf mistletoe occurrence for 13 of the 25 stands. The amount of living and dead black spruce basal area differed significantly based on model prediction and observed infestation, but trees per hectare, total living basal area, diameter at breast height, stand age, and species richness were not significantly different. Our results highlight the benefits of model benchmarking to improve model interpretation as well as to inform our understanding of forest health problems across diverse stand conditions.

Root rot damage in naturally regenerated stands of spruce and balsam fir in Ontario

1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney
Keyword(s):  
Root Rot ◽  
Black Spruce ◽  
Basal Area ◽  
Ground Level ◽  
White Spruce ◽  
Balsam Fir ◽  
Tree Age ◽  
Stand Age ◽  
Root Decay ◽  
Forest Region

In an 11-year study in northern Ontario, root rot damage was heaviest in balsam fir, intermediate in black spruce, and least in white spruce. As a result of root rot, 16, 11, and 6%, respectively, of dominant or codominant trees of the three species were killed or experienced premature windfall. Butt rot, which resulted from the upward extension of root rot into the boles of living trees, led to a scaled cull of 17, 12, and 10%, respectively, of gross merchantable volume of the remaining living trees in the three species. The total volume of wood lost to rot was, therefore, 33, 23, and 16%, respectively. Of 1108 living dominant and codominant balsam fir, 1243 black spruce, and 501 white spruce in 165 stands, 87, 68, and 63%, respectively, exhibited some degree of advanced root decay. Losses resulting from root rot increased with tree age. Significant amounts of root decay and stain (>30% of root volume) first occurred at 60 years of age in balsam fir and 80 years in black spruce and white spruce. For the three species together, the proportion of trees that were dead and windfallen as a result of root rot increased from an average of 3% at 41–50 years to 13% at 71–80 years and 26% at 101–110 years. The root rot index, based on the number of dead and windfallen trees and estimated loss of merchantable volume, also increased, from an average of 17 at 41–50 years to 40 at 71–80 years and 53 at 101–110 years. Death and windfall of balsam fir and black spruce were more common in northwestern Ontario than in northeastern Ontario. Damage to balsam fir was greater in the Great Lakes–St. Lawrence Forest region than in the Boreal Forest region. In all three tree species, the degree of root rot (decay and stain) was highly correlated with the number of dead and windfallen trees, stand age, and root decay at ground level (as a percentage of basal area) for a 10-tree sample.

Black spruce decline triggered by spruce budworm at the southern limit of lichen woodland in eastern Canada

2001 ◽  
Vol 31 (12) ◽  
pp. 2160-2172 ◽  
Author(s):  
Martin Simard ◽  
Serge Payette
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Jack Pine ◽  
Growth Patterns ◽  
Balsam Fir ◽  
Eastern Canada ◽  
Southern Limit ◽  
Epiphytic Lichen ◽  
Spruce Decline

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.

Postfire seed rain of black spruce, a semiserotinous conifer, in forests of interior Alaska

2009 ◽  
Vol 39 (8) ◽  
pp. 1575-1588 ◽  
Author(s):  
Jill Johnstone ◽  
Leslie Boby ◽  
Emily Tissier ◽  
Michelle Mack ◽  
Dave Verbyla ◽  
...  
Keyword(s):  
Structural Equation ◽  
Black Spruce ◽  
Fire Severity ◽  
Seed Viability ◽  
Basal Area ◽  
Seed Rain ◽  
Equation Modeling ◽  
Viable Seed ◽  
Interior Alaska ◽  
Total Seed

The availability of viable seed can act as an important constraint on plant regeneration following disturbance. This study presents data on seed quantity and quality for black spruce ( Picea mariana (Mill.) B.S.P.), a semiserotinous conifer that dominates large areas of North American boreal forest. We sampled seed rain and viability for 2 years after fire (2005–2007) in 39 sites across interior Alaska that burned in 2004. All sites were dominated by black spruce before they burned. Structural equation modeling was used to assess the relative importance of prefire spruce abundance, topography effects, canopy fire severity, and distance to unburned stands in explaining variations in black spruce seed rain. Prefire basal area of spruce that remained standing after fire was a significant predictor of total seed rain, but seed viability was more strongly related to site elevation, canopy fire severity, and distances to unburned stands. Although positive relations between tree basal area and the size of the aerial seed bank may place a first constraint on seed availability, accurate prediction of postfire viable seed rain for serotinous conifers also requires consideration of the effects of abiotic stress and canopy fire severity on seed viability.

scholarly journals The spruce budworm, a potential threat for Norway spruce in eastern Canada?

2020 ◽  
Vol 96 (01) ◽  
pp. 71-76
Author(s):  
Richard Berthiaume ◽  
Christian Hébert ◽  
Alain Dupont ◽  
Martin Charest ◽  
Éric Bauce
Keyword(s):  
North America ◽  
Norway Spruce ◽  
Black Spruce ◽  
Spruce Budworm ◽  
White Spruce ◽  
Pupal Weight ◽  
Potential Threat ◽  
Eastern Canada ◽  
Exotic Tree ◽  
Biological Performance

Norway spruce, an exotic tree species in North America, was largely used in reforestation programs in the province of Québec between 1972 and 1990. Several of these plantations are now reaching their commercial maturity and the resurgence of spruce budworm outbreak is a reminder that the potential threat of this damaging defoliator for Norway spruce still remains unknown. We used two life-history traits, pupal weight and overwintered larval (L2) weight, to compare spruce budworm biological performance on Norway spruce, white spruce and black spruce. Pupae collected on Norway spruce and overwintered larvae produced by parents that fed on Norway spruce were heavier than those coming from black spruce. Spruce budworm performance was similar on Norway and white spruce, showing similar suitability and suggesting that it can represent a potential threat for Norway spruce plantations established after the last spruce budworm outbreak in eastern North America.

Causality in mortality patterns of spruce trees during a spruce budworm outbreak

1989 ◽  
Vol 19 (5) ◽  
pp. 632-638 ◽  
Author(s):  
Akira Osawa
Keyword(s):  
Species Complex ◽  
Close Relationships ◽  
Tree Mortality ◽  
Black Spruce ◽  
Basal Area ◽  
Spruce Budworm ◽  
Red Spruce ◽  
Hybrid Index ◽  
The Mean ◽  
Spruce Mortality

Patterns of tree mortality in the species complex of red spruce (Picearubens Sarg.), black spruce (Piceamariana (Mill.) B.S.P.) and their possible hybrids that developed during a spruce budworm (Choristoneurafumiferana (Clem.)) outbreak in Maine, U.S.A., were analyzed in relation to five hypotheses of their causal mechanisms. The observed patterns of spruce mortality were primarily a result of the phenotypic variation among the spruces. Close relationships among the mean hybrid index of spruce trees in a plot and such stand variables as balsam fir (Abiesbalsamea (L.) Mill.) basal area and drainage index are likely to have created coincidental correlations between tree mortality and those variables that do not necessarily reflect causality.

Influence of recent fire season and severity on black spruce regeneration in spruce–moss forests of Quebec, Canada1This article is one of a selection of papers from the 7th International Conference on Disturbance Dynamics in Boreal Forests.

2012 ◽  
Vol 42 (7) ◽  
pp. 1316-1327 ◽  
Author(s):  
Mélanie Veilleux-Nolin ◽  
Serge Payette
Keyword(s):  
Organic Matter ◽  
Organic Material ◽  
Black Spruce ◽  
Fire Severity ◽  
Mineral Soil ◽  
Thick Layer ◽  
Fire Season ◽  
Eastern Canada ◽  
Postfire Regeneration ◽  
Crown Forest

Postfire regeneration problems compromise the maintenance of closed-crown forests of eastern Canada, often shifting toward lichen woodlands. Compounded disturbances like successive fires or insect outbreaks followed by fire may be responsible for this shift. Leaving behind unfavourable seedbeds for the germination of black spruce ( Picea mariana (Mill.) B.S.P.) seeds, low-severity fires may also be involved in this transformation. The severity of recent fires and their impact on black spruce regeneration were evaluated using 13 stands burned in spring or summer within the closed-crown forest in Quebec during the last 20 years. Two ecological indicators were used to characterize fire severity: thickness of residual organic material and recovery of plant species. Regardless of the season, the ground of all burned stands was covered with a thick layer of residual organic matter. Blackened organic matter and ericaceous vegetation, indicating the passage of a low-severity fire, were widespread in all sites whereas acrocarpous mosses and bare mineral soil, indicating the passage of a severe fire, were uncommon. The preponderance of the thick layer of residual organic material blackened at the surface can explain the failure of regeneration in most studied sites. Low-severity fires are thus among factors probably involved in the expansion of lichen woodlands within the closed-crown forest.

Age and size effects on seed productivity of northern black spruce

2013 ◽  
Vol 43 (6) ◽  
pp. 534-543 ◽  
Author(s):  
Jayme N. Viglas ◽  
Carissa D. Brown ◽  
Jill F. Johnstone
Keyword(s):  
Boreal Forest ◽  
Seed Production ◽  
Fire Regime ◽  
Black Spruce ◽  
Seed Viability ◽  
Basal Area ◽  
Yukon Territory ◽  
Stand Age ◽  
Seed Productivity ◽  
Cone Production

Slow-growing conifers of the northern boreal forest may require several decades to reach reproductive maturity, making them vulnerable to increases in disturbance frequency. Here, we examine the relationship between stand age and seed productivity of black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) in Yukon Territory and Alaska. Black spruce trees were aged and surveyed for cone production and seed viability across 30 even-aged stands ranging from 12 to 197 years old. Logistic regression indicated that individual trees had a ∼50% probability of producing cones by age 30 years, which increased to 90% by age 100 years. Cone and seed production increased steadily with age or basal area at both the tree and stand level, with no evidence of declining seed production in trees older than 150 years. Using published seed:seedling ratios, we estimated that postfire recruitment will be limited by seed availability in stands for up to 50 years (on high-quality seedbeds) to 150 years (low-quality seedbeds) after fire. By quantifying these age and seed productivity relationships, we can improve our ability to predict the sensitivity of conifer seed production to a range of disturbance frequencies and thus anticipate changes in boreal forest resilience to altered fire regime.

Susceptibility of balsam fir to spruce budworm defoliation as affected by thinning

1979 ◽  
Vol 9 (3) ◽  
pp. 428-435 ◽  
Author(s):  
Gregory W. Crook ◽  
Paul E. Vézina ◽  
Yvan Hardy
Keyword(s):  
Forest Type ◽  
Coniferous Forest ◽  
Basal Area ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Stand Age ◽  
Forest Types ◽  
Mixed Stands ◽  
Number Of Stems

Spruce budworm, Choristoneurafumiferana (Clemens), defoliation of balsam fir, Abiesbalsamea (L.) Mill., was studied in thinned stands of the Lower St. Lawrence region of Quebec. The object of the study was to quantify defoliation levels in treated and control plots in order to determine what effect, if any, thinning had on the susceptibility of balsam fir.Three main forest types were studied: (a) coniferous, (b) mixed, and (c) hardwood with a fir understory. The coniferous forest type was subdivided into three types: (1) pure balsam fir; (2) balsam fir – white spruce, Piceaglauca (Moench) Voss; (3) balsam fir – hardwoods. Defoliation levels were estimated using two current techniques: the Dorais–Hardy (1976) and the Fettes (1950) methods.Susceptibility of balsam fir to spruce budworm defoliation was not affected after thinning in coniferous and hardwood forest types; however, susceptibility was increased in mixed stands when part of the hardwood cover was removed. In any situation, defoliation of fir was found to be more intense with an increase of the basal area of the coniferous species (balsam fir, red spruce, Picearubens Sarg., and white spruce) while an increase of the basal area of hardwoods resulted in lower defoliation levels; likewise, a higher number of stems per hectare brought higher defoliation levels of fir. Defoliation was also found to vary with stand composition; susceptibility of fir in the three main cover types decreased in the following order: (a) coniferous, (b) mixed, (c) hardwood. Stand age was not a factor influencing the susceptibility of balsam fir for the two age classes studied (30 and 50 years).

Sign in / Sign up

Export Citation Format

Share Document