Root-rotting fungi in white spruce, black spruce, and balsam fir in northern Ontario

1995 ◽  
Vol 25 (8) ◽  
pp. 1209-1230 ◽  
Author(s):  
R.D. Whitney

Fungi associated with root rot in living trees were isolated and identified from 521 white spruce (Piceaglauca (Moench) Voss), 1342 black spruce (Piceamariana (Mill.) B.S.P.), and 1383 balsam fir (Abiesbalsamea (L.) Mill.) ranging in age from 26 to 208 years (at a 30-cm height), in 165 stands across northern Ontario. Trees were pulled out with the winch of a skidder, root decays and stains were measured, and cultures were made from root and butt sections. Armillaria spp., considered in this study to be mostly Armillariaostoyae (Romagn.) Herink, was the most frequently isolated fungus, occurring in 32, 34, and 46% of white spruce, black spruce, and balsam fir, respectively. Inonotustomentosus (Fr.:Fr.) S. Teng, Scytinostromagalactinum (Fr.) Donk, and Coniophoraputeana (Schumach.:Fr.) P. Karst. were next in frequency, in that order. An additional 26 Basidiomycetes were associated with lesser amounts of root rot in the three species. Armillariaostoyae infected, and remained mostly below ground in all three species, averaging less than 0.3 m in height up the stem in living trees, while most of the other major fungi advanced more than 0.5 m up the stem in average infected trees. The frequency of A. ostoyae in white spruce and black spruce increased with tree age to about 90 and 130 years, respectively, then leveled off, probably because of diseased trees falling from the stand. An age relationship was not found with this fungus in balsam fir. The other fungi generally increased in frequency of occurrence with tree age. The only major fungus that attacked living tissues (sapwood) exclusively to any extent was A. ostoyae. Some less frequent fungi such as Resiniciumbicolor (Albertini & Schwein.:Fr.) Parmasto and Serpulahimantioides (Fr.:Fr.) P. Karst. indicated pathogenicity by attacking sapwood initially. Armillariaostoyae infected significantly higher numbers of black spruce and balsam fir growing on dryer sites (soil moisture regimes (SMR) 1–3) than on wet sites (SMR 5–7). The only other fungus apparently related to moisture regime was unknown F, which infected black spruce more on wet than on dry sites. Significantly higher proportions of root and buttwood of all three species were infected with A. ostoyae and I. tomentosus in northwestern Ontario than in northeastern Ontario. Heavy to severe root rot caused tree height or diameter growth reductions when trees were infected by either A. ostoyae or I. tomentosus. An Ascomycete, Ascocorynesarcoides (Jacq.) Groves & D.E. Wilson, was associated with pink or faint brown stains, often near bark seams, in white spruce and black spruce. It was isolated from roots of 20 and 28% of these species, respectively.

1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney

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.


1985 ◽  
Vol 15 (5) ◽  
pp. 890-895 ◽  
Author(s):  
Roy D. Whitney ◽  
G. Blake MacDonald

Growth increments were compared on balsam fir (Abiesbalsamea (L.) Mill.) trees with varying amounts of decay on the stump (15 cm above ground) that originated from the roots. In 1612 trees, from 20 to 156 years of age on 139 plots across northern Ontario, the average height and radial increments over the last 3 years were 13.5 and 10.9% smaller, respectively, in trees with ground-level decay compared with trees having no decay at this level. Stand basal area was more useful than tree age as a stratification variable for revealing the effect of root rot on growth. Growth reductions were the smallest in trees with intermediate surrounding basal areas and in trees on drier or heavier textured soils.


1988 ◽  
Vol 64 (4) ◽  
pp. 345-351 ◽  
Author(s):  
R. D. Whitney

Armillaria root rot. caused most likely by Armillaria obscura (Pers) Herink, killed 6-to 21-year-old white spruce, black spruce, jack pine and red pine saplings in each of 49 plantations examined in northern Ontario. Annual mortality in the four species over the last 2 to 6 years averaged 1.4%, 1.5%, 0.5% and 0.2%, respectively. In all but one of 25 white spruce and red pine plantations (43 to 58 years old) in eastern and southern Ontario. Armillaria root rot was associated with mortality. Accumulated mortality in white spruce and red pine (initially recorded in 1978) averaged 7.6% and 11.7%, respectively, as of 1986. Current annual mortality for all plantations ranged from 0% to 16%. Key words: root rot. Armillaria obscura, white spruce, black spruce, jack pine, red pine.


2005 ◽  
Vol 81 (1) ◽  
pp. 56-60 ◽  
Author(s):  
R D Whitney ◽  
R N Irwin

Averages of 10, 10, 0 and 4% of white spruce, black spruce, balsam fir and jack pine saplings were killed by Armillaria Root Disease (ARD), after 10 years following planting around 50 infected stumps that had been prescribed burned. Comparable averages on an unburned control area of 8, 8, 0 and 6% were not significantly different from the burned area. ARD did not occur in any trees planted adjacent to five deeply burned stumps. However, no statistically significant relationship was found between ARD and intensity of burn on stumps. Significantly (p = .05) fewer balsam fir saplings were killed by ARD than of either white or black spruce. Jack pine heights were significantly greater (p = .05) than those of the other species on both locations after10 years, and on the unburned site after 17 years (experimental trees on the burned site were inadvertently cut during a silvicultural thinning in the year prior to measurements in the 17th year). Balsam fir heights were significantly less (p = .05) than those of the other three species on both sites after 10 years, and after 17 years on the unburned site. Key words: Root rot, Armillaria, burning, height growth, spruce, balsam fir, jack pine


1978 ◽  
Vol 8 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Roy D. Whitney ◽  
Donald T. Myren

The roots of 435 dead or dying saplings, averaging 10 years of age, of seven conifer species from the Boreal Forest of northern Ontario were examined for root rot. Only trees with no obvious cause of death or decline, other than root rot, were selected. Eighty-three percent of the trees had root rot. Cultures revealed that Armillariamellea (Vahl ex Fr.) Kummer was associated with root rot in 68% of all trees examined, including more than 45% of the trees in each species. Ten other root-rotting fungi were isolated from 1% or fewer of the trees, 7 of them from balsam fir (Abiesbalsamea [L.] Mill.) and 3 from black spruce (Piceamariana [Mill.] B.S.P.). Scytinostromagalactinum (Fr.) Donk was isolated from sapwood of roots and lower stems of red pine (Pinusresinosa Ait.), balsam fir, white pine (P. strobes L.), and black spruce and appeared to be parasitic on these species. Coniophoraputeana (Schum. ex Fr.) Karst. was apparently associated with the death of one balsam fir.


2003 ◽  
Vol 20 (4) ◽  
pp. 167-174
Author(s):  
Nobutaka Nakamura ◽  
Paul M. Woodard ◽  
Lars Bach

Abstract Tree boles in the boreal forests of Alberta, Canada will split once killed by a stand-replacing crown fire. A total of 1,485 fire-killed trees were sampled, 1 yr after burning, in 23 plots in 14 widely separated stands within a 370,000 ha fire. Sampling occurred in the Upper and Lower Foothills natural subregions. The frequency of splitting varied by species but averaged 41% for all species. The order in the frequency of splitting was balsam fir, black spruce, white spruce and lodgepole pine. The type of splitting (straight, spiral, or multiple) varied by species, as did the position of the split on the tree bole. Aspect or solar angle was not statistically related to the type or occurrence of splitting.


1995 ◽  
Vol 25 (2) ◽  
pp. 329-342 ◽  
Author(s):  
Pierre Pominville ◽  
Jean-Claude Ruel

An experiment was conducted to compare the effects of traditional clear-cutting with those of strip cutting on regeneration of black spruce, Piceamariana (Mill.) B.S.P., stands on scarified and unscarified uplands and on lowlands. To that effect, regeneration surveys were done before cutting, in the following year, and 3 and 5 years after cutting. Five years after harvesting, strip cutting led to higher coniferous stocking than clear-cutting on scarified uplands and on lowlands. On unscarified uplands, the gain attributable to strip cutting was not significant. The coniferous stocking of strip cuts on scarified uplands was not greater than on unscarified uplands. So the efficiency of scarification could not be proved in that study. Stocking obtained after 5 years remained closely related to the one observed immediately after harvesting in the strip cufs as in the clear-cuttings. This is particularly true for balsam fir, Abiesbalsamea (L.) Mill. In the strip cuts, the balsam fir stocking was constant while the one of black spruce increased. This could have an impact on the evolution of the composition of the new stands and, consequently, on their vulnerability to spruce budworm, Choristoneurafumiferana (Clem.). The majority of the clear-cuttings were well regenerated 5 years after harvesting. Their average coniferous stocking was slightly above 60%. However, 48% of the clear-cuttings did not reach this level when only unscarified plots on uplands were considered. Advance growth was abundant in those plots but suffered high losses during harvesting. Consequently, reducing the losses during harvesting would result in a lower proportion of clear-cuttings with insufficient coniferous stocking 5 years after cutting. On the other hand, almost all the strip cuts with insufficient regeneration after harvesting were well regenerated 5 years later. Thus, strip cutting could be an interesting option on sites with insufficient advance growth and on sites well regenerated before cutting but where important losses during harvesting are anticipated.


1981 ◽  
Vol 57 (6) ◽  
pp. 267-269 ◽  
Author(s):  
J. D. Simpson ◽  
G. R. Powell

Ten young black spruce (Picea mariana [Mill.] B.S.P.) plantations in northern and central New Brunswick were examined to de termine the influence of aspect, slope, tree age and tree height on pollen-cone and seed-cone production. It was found that a greater proportion of trees growing on southerly aspects produced pollen cones and seed cones than trees growing on northerly aspects. Trees growing on southerly aspects bore 2.5 and 5 times more seed cones and pollen cones, respectively, than trees growing on northerly aspects. Cone production on south-sloping sites was approximately double that on level sites. The number of seed cones was most significantly correlated with tree height. The number of pollen cones was most significantly correlated with number of seed cones.


1987 ◽  
Vol 17 (2) ◽  
pp. 105-108 ◽  
Author(s):  
Robert R. Gagnon ◽  
Eric Bauce ◽  
Marius Pineau

Cambial electrical resistance in 10 balsam fir (Abiesbalsamea (L.) Mill.) and 10 white spruce (Piceaglauca (Moench) Voss) trees in Québec was measured 42 times during July and August 1985. Simultaneous measurements of relative humidity and temperature were also taken so that water potential in air (ψa) could be determined. In both species, cambial electrical resistance, corrected to a constant temperature of 15 °C (CERCOR), was negatively correlated with ψa. On the other hand, 10 measurements on 14 balsam fir trees that had been severely defoliated by the spruce budworm (Choristoneurafumiferana (Clem.)) in 1983 and 1984, and 12 measurements on 14 protected trees showed that the correlation was stronger for sprayed trees than for those that had been defoliated. We propose that the correlation coefficient between cercor and ψa may be a useful index of tree vigor. However, in situations where plots can be visited only once during the season, cambial electrical resistance measurements should be made in the morning when the relative humidity is high.


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