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.

Relation between air water potential and cambial electrical resistance of balsam fir and white spruce after budbreak

1987 ◽  
Vol 17 (2) ◽  
pp. 105-108 ◽  
Author(s):  
Robert R. Gagnon ◽  
Eric Bauce ◽  
Marius Pineau
Keyword(s):  
Relative Humidity ◽  
Water Potential ◽  
Correlation Coefficient ◽  
Electrical Resistance ◽  
White Spruce ◽  
The Other ◽  
Balsam Fir ◽  
Simultaneous Measurements ◽  
Electrical Resistance Measurements ◽  
Made In

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.

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 defoliation and growth loss in young balsam fir: recovery of growth in spaced stands

1989 ◽  
Vol 19 (12) ◽  
pp. 1616-1624 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Volume Growth ◽  
Spruce Budworm ◽  
Complete Recovery ◽  
Balsam Fir ◽  
Growth Recovery ◽  
Shoot Production ◽  
Volume Increment ◽  
Growth Loss ◽  
Major Factors ◽  
Foliar Biomass

Trees defoliated by the spruce budworm (Choristoneurafumiferana (Clem.)) for 1 to 4 years and subsequently protected rapidly regained foliar biomass. Three plots of 25- to 30-year-old balsam fir (Abiesbalsamga (L.) Mill.) trees, on the Cape Breton Highlands of Nova Scotia, were studied. Two major factors contributed to the rapid growth recovery rates: the ability to produce epicormic shoots, combined with increased retention of older age-classes of needles, and the development of new foliage at the expense of volume growth. A complete recovery of volume increment occurred after 2 years of extreme defoliation, but not after 4 years of severe defoliation. Epicormic shoot production was only associated with shoot and bud destruction and therefore, growth recovery was slow after partial defoliation of only current foliage. In all plots studied, there was a lag of 2 to 3 years between increased foliar biomass and significant increases in volume increment.

The relation of balsam fir volume increment to cumulative spruce budworm defoliation

1996 ◽  
Vol 72 (5) ◽  
pp. 533-540 ◽  
Author(s):  
David A. MacLean ◽  
Eldon S. Eveleigh ◽  
Tony L. Hunt ◽  
Mervyn G. Morgan
Keyword(s):  
Specific Volume ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Regression Equations ◽  
Growth Reduction ◽  
Stem Analysis ◽  
Volume Increment ◽  
Mill Stand

The effect of cumulative defoliation caused by spruce budworm (Choristoneura fumiferana [Clem.]) from 1981 to 1987 on tree growth was assessed in a 35-year-old balsam fir (Abies balsamea [L.] Mill.) stand. After six years of moderate to severe defoliation, specific volume increment was reduced by an average of 11, 55, 83, 70, and 83% for trees with visual cumulative defoliation ratings, in 1987, of 1–25%, 26–50%, 51–75%, 76–90%, and 91–100%, respectively. Following defoliation, mean specific volume increment ranged from 0.02 cm3 cm−2 year−1 for trees with >90% cumulative defoliation to 0.16 cm3 cm−2 year for trees with <25% defoliation. Specific volume increment and percentage growth reduction were significantly related to the cumulative defoliation rating, with regression equations explaining 72 and 64%, respectively, of the variability among trees. It was concluded that onetime visual ratings of cumulative defoliation caused by spruce budworm can be used in assessing balsam fir growth rates and growth reduction. Key words: growth reduction, specific volume increment, stem analysis, Choristoneura fumiferana, Abies balsamea

Spruce budworm defoliation and growth loss in young balsam fir: artificial defoliation of potted trees

1990 ◽  
Vol 20 (7) ◽  
pp. 902-909 ◽  
Author(s):  
H. Piene ◽  
C.H.A. Little
Keyword(s):  
Specific Volume ◽  
Spruce Budworm ◽  
Experimental Period ◽  
Height Growth ◽  
Balsam Fir ◽  
Growth Responses ◽  
Volume Increment ◽  
Defoliation Treatment ◽  
Growth Loss ◽  
Foliage Weight

To simulate feeding by the spruce budworm (Choristoneurafumiferana Clem.), potted, 5-year-old balsam fir (Abiesbalsamea (L.) Mill.) trees were artificially defoliated at the peak of the sixth instar period in the first 1, 2, or 3 years of a 3-year experiment. This schedule allowed trees that were defoliated in the first 1 or 2 years to recover for 2 years and 1 year, respectively. Seven treatments were applied: 0, 33, 66, 90, or 100% of the current-year needles were manually removed, all current-year needles were clipped using scissors (clip treatment), or all current-year shoots were severed at their base (100+ treatment). The dry weights of stem axis, branch axes, and roots were measured at the end of the 3rd year, and current-year and total foliage weight, height growth, and specific volume increment were determined for each year of the experimental period. Needle removal decreased growth throughout the tree, the growth loss increasing with increasing intensity and frequency of defoliation. In the 1st year of defoliation, all treatments reduced specific volume increment, whereas only the 100+ treatment decreased height growth. In every defoliation year, specific volume increment, height growth (manifested in the year following the defoliation), and the final weights of stem axis, branch axes, and roots were generally related curvilinearly to total foliage weight. The 100% and 100+ treatments induced the sprouting of axillary and nodal buds that remained dormant in undefoliated trees. Retaining the defoliated shoot axes (100% treatment), compared with removing them (100+ treatment), increased specific volume increment. Retaining the needle base (clip treatment) prevented the apex necrosis that occurred in some shoots subjected to the 100% treatment. In trees allowed to recover, specific volume increment increased in the 1st year, the degree of recovery increasing with decreasing intensity and frequency of prior defoliation treatment. After 2 recovery years, specific volume increment and height growth were not affected by any previous defoliation treatment, and current-year foliage weight and stem axis weight were decreased only by the 100+ treatment; however, there was still an inhibitory effect of all treatments on the weights of total foliage, branch axes, and roots. The growth responses found in the present investigation were compared with those observed in balsam fir trees defoliated by the spruce budworm.

Characterization of Phase Transitions Occurring in Solution Treated Ti-15Mo during Heating by Thermal Expansion and Electrical Resistance Measurements

2016 ◽  
Vol 879 ◽  
pp. 2318-2323 ◽  
Author(s):  
Pavel Zháňal ◽  
Petr Harcuba ◽  
Michal Hájek ◽  
Jana Šmilauerová ◽  
Jozef Veselý ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Titanium Alloy ◽  
Phase Transitions ◽  
Electrical Resistance ◽  
Temperature Changes ◽  
Solution Treated ◽  
Electrical Resistance Measurements ◽  
Ongoing Phase

Metastable β titanium alloy Ti-15Mo was investigated in this study. In-situ electrical resistance and thermal expansion measurements conducted on solution treated material revealed influence of ongoing phase transitions on measured properties. The monotonicity of the dependence of electrical resistance on temperature changes at 225, 365 and 560 °C The thermal expansion deviates from linearity between 305 and 580 °C.

Sign in / Sign up

Export Citation Format

Share Document