Electrical resistance and capacitance measurements on young, spaced and unspaced, defoliated and protected, balsam fir trees

1984 ◽  
Vol 14 (6) ◽  
pp. 811-817 ◽  
Author(s):  
H. Piene ◽  
D. S. Fensom ◽  
J. E. McIsaac ◽  
R. G. Thompson ◽  
K. G. Alexander
Keyword(s):  
Nova Scotia ◽  
Electrical Properties ◽  
Electrical Resistance ◽  
Balsam Fir ◽  
Capacitance Measurements ◽  
Cyclic Patterns ◽  
Cape Breton ◽  
Dead Trees ◽  
Foliar Biomass

Electrical resistance and capacitance were measured in 1981 and 1982 on 25- to 30-year-old spaced and unspaced, defoliated and protected balsam fir (Abiesbalsamea (L.) Mill.) trees on the Cape Breton Highlands, Nova Scotia. Significantly higher average electrical resistance readings were observed for the spaced and unspaced, defoliated trees than for the comparable protected trees. With one exception, the average capacitance was significantly lower in defoliated compared with protected trees. In general, for both the defoliated and protected trees, decreases in average electrical resistance were associated with increases in foliar biomass. Caution has to be taken when monitoring electrical properties in the field because of seasonal cyclic patterns, and aberrations in tissues of dying or dead trees.

Spruce budworm populations, defoliation, and changes in stand condition during an uncontrolled spruce budworm outbreak on Cape Breton Island, Nova Scotia

1989 ◽  
Vol 19 (9) ◽  
pp. 1077-1086 ◽  
Author(s):  
Donald P. Ostaff ◽  
David A. MacLean
Keyword(s):  
Nova Scotia ◽  
Tree Mortality ◽  
Total Mortality ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Dead Trees ◽  
Spruce Mortality ◽  
Third Instar Larvae

Effects of an uncontrolled spruce budworm (Choristoneurafumiferana (Clem.)) outbreak in 20 mature balsam fir (Abiesbalsamea (L.) Mill.) stands on Cape Breton Island, Nova Scotia, were studied from 1976 to 1985. Spruce budworm populations were extremely high, higher than peak levels recorded for other outbreaks, and averaged over 380 third-instar larvae per square metre of foliage from 1976 to 1980. As many as 1570 third-instar larvae per square metre occurred 5 to 7 years after the start of the outbreak, resulting in complete current defoliation and back-feeding on older foliage. Stands were divided into three groups, based on the pattern of cumulative current defoliation; the sum of current annual defoliation during the outbreak was 343, 445, and 543% for these groups, equivalent to the removal of 3.5 to 5.5 age-classes of foliage. Budworm defoliation caused the death of 78, 80, and 89% of the merchantable balsam fir volume in the three groups of stands, respectively, as well as 27% of the spruce (Picea sp.) volume; another 39% of the spruce volume died as a result of spruce beetle (Dendroctonusrufipennis Kby.) activity. Fir mortality commenced 3 years after the start of the outbreak and spruce mortality 2 to 3 years later. About one-half of the total mortality occurred in the 4 years after budworm populations and defoliation returned to low levels. Tree mortality and loss of foliage opened the stands, and 4 years after the collapse of the outbreak, 4% of the surviving trees and 17% of the dead trees had blown down, whereas 60% of all trees had broken tops.

Electrical resistance measurements on young balsam fir trees in relation to specific volume increment, foliar biomass, and ion content of bark and wood

1984 ◽  
Vol 14 (2) ◽  
pp. 177-180 ◽  
Author(s):  
H. Plene ◽  
R. G. Thompson ◽  
J. E. McIsaac ◽  
D. S. Fensom
Keyword(s):  
Electrical Resistance ◽  
Specific Volume ◽  
Balsam Fir ◽  
Ion Content ◽  
Volume Increment ◽  
Electrical Resistance Measurements ◽  
Foliar Biomass

Electrical resistance in young balsam fir (Abiesbalsamea (L.) Mill.) trees was inversely (nonlinear) correlated with specific volume increment, total foliar biomass, and the combined weight of the current and 1-year-old foliage. These relationships were stronger before budbreak than after. No relationship existed between concentrations of N, P, K, Ca, and Mg in the bark and wood collected around time of budbreak, and electrical resistance.

CHANGES IN SPRUCE BUDWORM DEFOLIATION WITH CROWN LEVEL

1996 ◽  
Vol 128 (6) ◽  
pp. 1109-1113 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Nova Scotia ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Cost Effective ◽  
Balsam Fir ◽  
Crown Length ◽  
Cape Breton ◽  
Cost Effective Approach ◽  
The Common

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.

Timing of Spacing Operations in Young Balsam Fir Stands

1982 ◽  
Vol 58 (2) ◽  
pp. 93-95 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Nova Scotia ◽  
Volume Growth ◽  
Balsam Fir ◽  
Optimum Time ◽  
Cape Breton

Manual spacing, and corridor spacing in combination with hand spacing are recommended to increase volume growth in dense young balsam fir stands on the Cape Breton Highlands, Nova Scotia. Optimum time of spacing ranges from approximately release age 7 in a stand with 40 000 stems/ha to 12 in a stand with 10 000 stems/ha.

Patterns of balsam fir mortality caused by an uncontrolled spruce budworm outbreak

1989 ◽  
Vol 19 (9) ◽  
pp. 1087-1095 ◽  
Author(s):  
David A. MacLean ◽  
Donald P. Ostaff
Keyword(s):  
Tree Mortality ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Regression Equations ◽  
Cape Breton Island ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Cape Breton ◽  
Dead Trees ◽  
Site Characteristics

Tree mortality caused by spruce budworm (Choristoneurafumiferana (Clem.)) defoliation was assessed annually from 1976 to 1985 in 20 mature balsam fir (Abiesbalsamea (L.) Mill.) stands on Cape Breton Island, Nova Scotia, and was related to defoliation and to tree, stand, and site characteristics. Ten to 12 years after the start of the budworm outbreak, fir mortality averaged 87% of the merchantable volume (range 60–100%) among the stands. Timing of mortality was similar to that found in studies of previous outbreaks. In the first 4 years of the outbreak, virtually all the trees that died had more than 90% cumulative defoliation but, overall, 64, 21, and 14% of the dead trees had cumulative defoliation >90, 76 to 90, and 51 to 75%, respectively. Early in the outbreak, fir mortality was generally negatively correlated with tree vigor, relative crown position, or diameter at breast height, but in later years, trees were killed irrespective of these factors. Fir mortality was evenly distributed among different sized trees, and 73 to 86% of the trees in each 5 cm diameter at breast height class died. A linear regression equation between dead fir volume and total fir volume explained 89% of the variability in mortality among stands. Percent fir mortality was correlated (r = 0.84) with visual estimates of cumulative defoliation (including all age-classes of foliage) in 1981, but mortality was not correlated with cumulative current annual defoliation or with site characteristics. Using regression equations, fir mortality during this budworm outbreak was predicted to within ±6 m2/ha in 14 of 18 (78%) of the stands, with a relative accuracy of 17.7%.

Spruce budworm defoliation and growth loss in young balsam fir: defoliation in spaced and unspaced stands and individual tree survival

1989 ◽  
Vol 19 (10) ◽  
pp. 1211-1217 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Tree Mortality ◽  
Spruce Budworm ◽  
Shoot Elongation ◽  
Balsam Fir ◽  
Individual Tree ◽  
Cape Breton ◽  
Tree Survival ◽  
Growth Loss ◽  
Individual Trees ◽  
Foliar Biomass

A severe outbreak of spruce budworm (Choristoneurafumiferana (Clem.)) began in 1976 in young, spaced and unspaced stands of balsam fir (Abiesbalsamea (L.) Mill.) located on the Cape Breton Highlands, Nova Scotia, Canada. A study was initiated that year to relate decreases in foliar biomass, caused by defoliation, to reductions in annual volume increment. Detailed defoliation assessments on individual trees from 1976 to 1984 showed severe defoliation of the current foliage in 1976. In 1977 and 1978, current foliage was destroyed in the early part of shoot elongation and severe back-feeding occurred on older age-class needles. After 1978, defoliation decreased as a result of a decline in budworm populations and, in general, only the current foliage was defoliated until the populations decreased to low levels in 1983. Defoliation was significantly higher in spaced than in unspaced stands in 1977, 1978, and 1980, and as a result, by 1984, average tree mortality caused by spruce budworm was 43.8% in spaced and 18.9%.in unspaced stands. The survival of some balsam fir trees and not others following a budworm outbreak is not related to differential defoliation, but to the ability of some balsam fir trees to rapidly increase foliar biomass through prolific epicormic shoot growth.

Forest structure and site conditions of boreal felt lichen (Erioderma pedicellatum) habitat in Cape Breton, Nova Scotia, Canada

Botany ◽  
2018 ◽  
Vol 96 (7) ◽  
pp. 449-459
Author(s):  
T.D. Power ◽  
R.P. Cameron ◽  
T. Neily ◽  
B. Toms
Keyword(s):  
Nova Scotia ◽  
Forest Structure ◽  
Abies Balsamea ◽  
Basal Area ◽  
Geographical Information ◽  
Slope Aspect ◽  
Site Conditions ◽  
Cape Breton ◽  
Dead Trees ◽  
Crown Closure

Boreal felt lichen [Erioderma pedicellatum (Hue) P.M. Jorg. (1972)] occurs on mainland Nova Scotia as well as Cape Breton, growing almost entirely on balsam fir [Abies balsamea (L.) Mill.] in wet coastal forests. A Geographical Information System (GIS) based predictive model for E. pedicellatum habitat in Nova Scotia has facilitated surveys and guided conservation. We used this model to examine the relationship between presence of E. pedicellatum and forest structure (tree DBH, height, age, and crown closure, inter-tree distance, basal area of live and dead trees, and percent cover of shrubs, herbs, Sphagnum spp., and other mosses), and site conditions (topographic position, slope, aspect, and drainage) as well as the presence of lichen indicator species. Erioderma pedicellatum sites had significantly older trees, higher density of live trees, lower crown closure, lower basal area of live Picea mariana (Mill.) Britton, Sterns & Poggenb., lower basal area of live trees, higher basal area of dead trees, higher Sphagnum spp. cover, and lower shrub cover than unoccupied habitat. Erioderma pedicellatum sites were significantly less well drained and occurred on steeper slopes with a north or east aspect. Four macrolichens (Coccocarpia palmicola, Platismatia norvegica, Lobaria scrobiculata, and Sphaerophorus globosus) occurred at a significantly higher frequency at E. pedicellatum sites.

The Sydney Coalfield of Cape Breton, Nova Scotia

1894 ◽  
Vol 38 (984supp) ◽  
pp. 15724-15725
Author(s):  
Hugh Fletcher
Keyword(s):  
Nova Scotia ◽  
Cape Breton
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