Root-rotting fungi associated with mortality of conifer saplings in northern Ontario

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.

2006 ◽  
Vol 36 (10) ◽  
pp. 2474-2485 ◽  
Author(s):  
Robert G Wagner ◽  
Andrew P Robinson

The influence of the timing and duration of interspecific competition on planted jack pine (Pinus banksiana Lamb.), red pine (Pinus resinosa Ait.), eastern white pine (Pinus strobus L.), and black spruce (Picea mariana (Mill.) BSP) was assessed using 10-year growth responses in a northern Ontario experiment. Stand volume was 117%, 208%, 224%, and 343% higher for jack pine, red pine, white pine, and black spruce, respectively, with 5 years of vegetation control than with no vegetation control. Stand volume increased linearly with number of years of vegetation control, and the slope of the relationship varied among conifer species. Change-point regression analysis was used to derive segmented weed-free and weed-infested curves, and to simultaneously estimate key critical-period parameters. Weed-free and weed-infested curves in the 10th year were similar to those derived in year 5, indicating that the patterns established during the first few years after planting were relatively robust for the first decade. The critical-period was 2 and 3 years after planting for jack pine and red pine, respectively, and occupied most of the 5-year period for white pine and black spruce. Principal components analysis of the vegetation community indicated that repeated herbicide applications caused differential shifts in the relative abundance of shrub, fern, and moss species through the 10th year. Species richness, however, was not substantially different between the untreated control and the most intensive treatments. Difference modeling was used to quantify how annual volume increment during the first decade varied with time, conifer species, cover of woody and herbaceous vegetation, and stage of development.


1959 ◽  
Vol 91 (10) ◽  
pp. 670-671 ◽  
Author(s):  
G. A. Bradley

While working at Cedar Lake in Northwestern Ontario in the summers of 1957 and 1958 the author was able to observe the feeding sites of various species of Cinara. Most of the observations were made within an area of a few square miles on either side of Highway 105, between Red Lake Road and Ear Falls, Ontario. This area is fairly typical of the Laurentian Shield, with numerous lakes, rocky ridges, sandy patches, and small bogs. The principal coniferous trees in this locality are black spruce, jack pine, and balsam fir. White spruce, white cedar, white pine, red pine, and common juniper are also present.


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.


1977 ◽  
Vol 109 (9) ◽  
pp. 1199-1202 ◽  
Author(s):  
Jeremy N. McNeil ◽  
Johanne Delisle ◽  
R. J. Finnegan

AbstractAn inventory was taken of aphid species occurring on balsam fir, white spruce, larch, red pine, white pine, jack pine, and black spruce at two sites where the introduced red wood ant, Formica lugubris Zett., had been released. Twenty-one aphid species were found, all in the genus Cinara Curtis. Nine of these species, and possibly a tenth, were new records for Quebec. Observations on colony size and distribution on host trees, in ant infested and control blocks, were recorded.


1985 ◽  
Vol 15 (1) ◽  
pp. 148-155 ◽  
Author(s):  
P. A. Thomas ◽  
Ross W. Wein

Surface-charred organic matter is a common but unfavourable postfire seedbed in eastern Canada. Slatted screens providing 0, 25, 50, and 75% cover were used to shelter 1-m2 charred plots from direct sunlight. Plots were sown with four conifer species. Jack pine (Pinnsbanksiana Lamb.) established abundantly on all plots and dominated on unsheltered areas. As shelter increased, eastern white pine (Pinusstrobus L.), and eventually balsam fir (Abiesbalsamea (L.) Mill.) and black spruce (Piceamariana (Mill.) B.S.P.) increased in number. Thus, the size and composition of the seedling community depended upon the amount of shelter given. To test whether postfire herbaceous and shrub vegetation could have a similar effect, seeds were sown on pairs of charred 1-m2 plots. Vegetation was removed weekly from one plot of each pair. Removal of vegetation decreased the establishment of balsam fir and black spruce but not red pine (Pinusresinosa Ait.). It was concluded that, during the first growing season, changes in vegetation cover produce changes in establishment similar to those found using slatted screens. Increasing fire severity (organic matter consumption) may reduce the postfire vegetation cover. A hypothetical model is presented, linking the establishment of the above five species to fire severity.


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.


1965 ◽  
Vol 43 (2) ◽  
pp. 305-316 ◽  
Author(s):  
J. J. Clausen ◽  
T. T. Kozlowski

Adaptations of Weatherley's relative turgidity technique (Weatherley 1950), fitting it for use with red pine (Pinus resinosa Ait.), white pine (P. strobus L.), balsam fir (Abies balsamea (L.) Mill.), and eastern hemlock (Tsuga canadensis (L.) Carr.) are described. Results of preliminary investigations of sampling variation between trees, whorls, and needle ages in red pine are presented.


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.


1970 ◽  
Vol 46 (6) ◽  
pp. 477-478
Author(s):  
W. C. Stevens

Northern Ontario lies entirely in the Precambrian Shield with its many rock outcrops, sand plains, valleys and extensive lowlands.Tree planting started on a limited scale in Northern Ontario in the 1920's but it was not until the mid-fifties that the program really expanded into millions of trees.White spruce, black spruce, jack pine, red pine and white pine are the most important species planted for commercial forest products.The advent of new site preparation techniques has made possible the planting of areas that were previously by-passed.Due to the rugged conditions in Northern Ontario, tree planting by machine is still not too prevalent.For the purpose of this paper, Northern Ontario is that portion of the province lying north of the historic fur-trading route of the French and Mattawa Rivers and the Great Lakes. The area is made up entirely of Precambrian shield with many outcrops of rock, sand plains of jack pine, valleys and extensive lowlands of spruce.


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