Mechanism relating cambial electrical resistance to periodic growth rate of balsam fir

1983 ◽  
Vol 13 (3) ◽  
pp. 472-480 ◽  
Author(s):  
Robert O. Blanchard ◽  
Walter C. Shortle ◽  
Weston Davis
Keyword(s):  
Growth Rate ◽  
New Hampshire ◽  
Electrical Resistance ◽  
Spruce Budworm ◽  
Probable Mechanism ◽  
Potassium Content ◽  
Balsam Fir ◽  
Periodic Growth ◽  
Cambial Zone

Cambial electrical resistance (CER) and periodic growth rate (PGR) of canopy balsam fir (Abiesbalsamea L.) trees were determined on 26 sites in Maine, New Hampshire, and Vermont, U.S.A., varying in level of spruce budworm defoliation. Determinations of water and potassium concentrations were made of the bark, wood, and vascular cambial zone (VCZ). Low CER was associated with high PGR and vice versa. A decline in PGR on all 26 sites was detected during early 1970's to late 1970's. It was not associated with, but may have been exacerbated by, spruce budworm defoliation. The most probable mechanism relating CER to PGR in balsam fir was variation in the thickness of VCZ and its correlation with potassium content. Thicker VCZ of faster growing trees released more potassium into the solution contacting electrodes than thinner VCZ of slower growing trees.

Cambial electrical resistance related to the number of vascular cambial cells in balsam fir

1984 ◽  
Vol 14 (6) ◽  
pp. 950-952 ◽  
Author(s):  
K. T. Smith ◽  
R. O. Blanchard ◽  
W. C. Shortle
Keyword(s):  
Electrical Resistance ◽  
Growing Season ◽  
Balsam Fir ◽  
Periodic Growth ◽  
Cambial Zone ◽  
Dormant Season ◽  
Cambial Cells ◽  
The Relationship ◽  
Number Of Cells ◽  
Scanning Electron

Cambial electrical resistance (CER) was related to the number of cells per radial file of vascular cambium in dominant and codominant balsam fir (Abiesbalsamea (L.) Mill.) trees sampled during the growing season. Scanning electron microscopy (SEM) was used to examine the vascular cambial zone (VCZ) of balsam fir during the growing and dormant seasons. Trees selected for SEM were categorized as having growing season CER < 10 kΩ or CER > 12 kΩ. The two growing trees with CER < 10 kΩ had a mean of seven cells per radial file of VCZ in contrast with four cells per radial file in the two trees of CER > 12 kΩ. Trees of either growing season category had dormant season CER > 12 kΩ and four cells per radial file of VCZ. The relationship between CER and the number of cells per radial file of VCZ supports the hypothesis relating CER to periodic growth rate in balsam fir.

Potential hazard rating system for fir stands infested with budworm using cambial electrical resistance

1980 ◽  
Vol 10 (4) ◽  
pp. 541-544 ◽  
Author(s):  
Weston Davis ◽  
Walter Shortle ◽  
Alex Shigo
Keyword(s):  
New Hampshire ◽  
Electrical Resistance ◽  
Spruce Budworm ◽  
Red Spruce ◽  
Balsam Fir ◽  
Rating System ◽  
Diameter Growth ◽  
Potential Hazard ◽  
Index Value ◽  
Hazard Rating

Cambial electrical resistance (CER) of more than 10 000 trees, predominantly balsam fir (Abiesbalsamea) and red spruce (Picearubens) was measured in 90 stands in northern Maine, New Hampshire, and Vermont, U.S.A. CER index values (mean CER, kiloohms per stand) ranged from 9 to 13 for fir in nonoutbreak situations, and 9 to 18 in outbreak situations with moderate to heavy budworm infestation, whereas values for red spruce remained essentially constant at 7 to 13 in both situations. Balsam fir trees in stands with an index value of 9 grew almost three times faster (diameter growth) than in stands with an index value of 13. An increase of index values from 13 to 18 in outbreak situations indicated no further reduction in growth, but may indicate impending mortality of trees with lower vitality. Such index values may be useful in developing a hazard rating system for fir stands infected with spruce budworm.

Observations on fungi associated with spruce budworm infested balsam fir needles

1985 ◽  
Vol 15 (5) ◽  
pp. 896-901 ◽  
Author(s):  
J. David Miller ◽  
D. Strongman ◽  
N. J. Whitney
Keyword(s):  
Growth Rate ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Toxic Effects ◽  
Freeze Dried ◽  
Phylloplane Fungi ◽  
Conifer Needle

Fungi (ca. 2000 isolates) were isolated from balsam fir needles infested by the spruce budworm (Choristoneurafumiferana Clem.) as well as from uninfested needles. Most of the isolates were well-known colonizers of the conifer needle phylloplane. However, approximately 6% of the isolates obtained from the infested needles were unusual needle phylloplane fungi and some of these were toxigenic and (or) pathogenic. Some isolates (23) associated with the needles, frass, and larvae were cultured; solvent extracts of the freeze-dried material of some of these were cytotoxic to HeLa 229 cells. The isolates showing cytotoxicity were grown and the resulting hyphae were incorporated (1%, w/w) into a spruce budworm diet. Hyphae from several isolates in these diets resulted in slower growth rate and mortality. The results of this study show that the presence of the spruce budworm altered the phylloplane mycoflora and the data suggest that there are toxic effects to spruce budworm that consume phylloplane fungi.

scholarly journals Coupe préparatoire et croissance en surface terrière d'une sapiniére de seconde venue à la forêt modèle du Bas-Saint-Laurent, Québec

2001 ◽  
Vol 77 (4) ◽  
pp. 685-695 ◽  
Author(s):  
Richard Zarnovican ◽  
Jean-Martin Lussier ◽  
Claude Laberge
Keyword(s):  
Growth Rate ◽  
Relative Size ◽  
Basal Area ◽  
Balsam Fir ◽  
Basal Area Growth ◽  
Periodic Growth ◽  
Area Growth ◽  
Crown Characteristics ◽  
Highly Correlated ◽  
The Impact

Balsam fir basal area growth was studied 5 years after the preparatory cut in the context of natural regeneration by the shelterwood system. The study was carried out in a 60-year-old second-growth balsam fir-yellow birch stand. The felling trials were realized in 16 plots and consisted of control and three felling regimes (15, 30 and 45% of removed basal area). The periodic (5 years) mean growth rate on dbh of trees in plots varies between 6 and 12% in response to felling intensity. The basal area of plots presents a mean periodic growth rate of 7.4% independently of felling intensity. There are highly significant correlations between the live crown characteristics and periodic basal area growth. This growth is highly correlated with inital diameter and intensity of felling. The trees of higher relative size are more productive than the others and the impact of felling on periodic basal area growth is significant when the intensity of felling is greater than 30%. Conversely, the ratio between periodic basal area growth after treatment and periodic basal area growth before treatment is correlated only with the intensity of felling. Finally, intensity of felling had no effect on periodic basal area growth per square meter of crown projected area. Key words: preparatory felling, basal area growth, balsam fir

Root movement and root damage of red spruce and balsam fir on subalpine sites in the White Mountains, New Hampshire

1988 ◽  
Vol 18 (8) ◽  
pp. 991-1001 ◽  
Author(s):  
D. M. Rizzo ◽  
T. C. Harrington
Keyword(s):  
Growth Rate ◽  
New Hampshire ◽  
Red Spruce ◽  
Balsam Fir ◽  
Root Damage ◽  
Cross Sectional ◽  
White Mountains ◽  
Wind Exposure ◽  
Crown Dieback ◽  
Root Movement

Crown dieback and mortality of red spruce and balsam fir in the subalpine zone of the northern Appalachian Mountains have been attributed to wind-induced crown and root damage. Vertical root movements, damage to roots and crowns, and growth rate were measured on wind-exposed spruce and fir trees near canopy gaps at Kancamagus Pass (875 m elevation) and Wildcat Mountain (1160 m) in the White Mountain National Forest, New Hampshire. Root movements were significantly correlated with windspeed, crown exposure, and depth of soil to rock. Woody roots that had made movements in excess of 10 mm had fewer small (1–3 mm diameter) roots, more abrasion wounds, and a greater amount of nonconducting (dry or discolored) xylem than roots that had made smaller movements. Hydraulic conductivity was significantly reduced in roots with greater than 40% xylem cross-sectional area that was nonconducting. Spruce and fir trees at gap margins grew slower and had more root and crown damage than trees sheltered within the canopy. Decreases in growth rate of spruce and fir trees at both sites during the past 20 years were significantly correlated with wind exposure and some of the root and crown damage variables.

Réduction de croissance en volume occasionnée au sapin baumier, suite à la défoliation par la tordeuse des bourgeons de l'épinette

1985 ◽  
Vol 61 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Louis Archambault ◽  
Jean Beaulieu
Keyword(s):  
Growth Rate ◽  
Choristoneura Fumiferana ◽  
Volume Growth ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Diameter Growth ◽  
Ottawa River ◽  
Epidemic Period ◽  
Growth Loss

A method was developed to determine the growth losses in volume in surviving balsam fir following a spruce budworm outbreak that occurred in the Ottawa River Valley in Quebec. Equations expressing the diameter growth rate had there been no infestation were developed. These equations were applied to balsam fir surviving the epidemic so as to determine what their diameters would have been without defoliation. Subsequently, the theoretical volumes were assessed using these diameters. The method was validated for the pre-epidemic period and precision was superior to 90%. Analyses revealed the outbreak caused a 49% volume growth loss to balsam fir for a period of approximately 10 years. Key words: Spruce budworm (Choristoneura fumiferana (Clem.)), balsam fir (Abies balsamea (L.) Mill.), growth losses.

scholarly journals Predicting balsam fir mortality in boreal stands affected by spruce budworm

2021 ◽  
Vol 496 ◽  
pp. 119408
Author(s):  
Djidjoho Julien Houndode ◽  
Cornelia Krause ◽  
Hubert Morin
Keyword(s):  
Spruce Budworm ◽  
Balsam Fir

Weather and Outbreaks of the Spruce Budworm in the Province of Quebec from 1939 to 1956

1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
The Past ◽  
Forest Regions ◽  
Tree Component ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Nearly all forest regions in the Province of Quebec where balsam fir (Abies balsamea (L.) Mill.) is an important tree component have been subjected to severe defoliation by the spruce budworm, Choristoneura fumiferana (Clem.), during the past 20 years. These outbreaks have followed an easterly direction beginning near the Ontario-Quebec border in 1939 and ending in the Gaspé Peninsula in 1958.

The influence of hardwood content on balsam fir defoliation by spruce budworm

1996 ◽  
Vol 26 (9) ◽  
pp. 1620-1628 ◽  
Author(s):  
Qiong Su ◽  
Ted D. Needham ◽  
David A. MacLean
Keyword(s):  
New Brunswick ◽  
Natural Enemies ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Generalized Model ◽  
Stand Management ◽  
Working Hypothesis ◽  
Model Combining

Changing stand composition by increasing hardwood content has been suggested as a long-term method for reducing susceptibility and vulnerability of balsam fir (Abiesbalsamea (L.) Mill.) to spruce budworm (Choristoneurafumiferana (Clem.)). Twenty-five mixed balsam fir–hardwood stands were selected in northern New Brunswick, with five stands in each 20% hardwood class (0–20, 21–40%, etc.). Defoliation each year from 1989 to 1993 was significantly (p < 0.0001) related to hardwood content, with r2 ranging from 0.57 to 0.81. As hardwood content increased, defoliation of balsam fir decreased. From 1989 to 1992, the years of moderate to severe defoliation, balsam fir stands with <40% hardwoods sustained 58–71% defoliation, on average, versus 12–15% defoliation in stands with >80% hardwood. A generalized model combining hardwood content and the estimated defoliation in pure softwood stands in a given year explained 77% of the variation in defoliation over stands and years. This study indicated that mixed balsam fir–hardwood stand management, with hardwood content >40%, could substantially reduce losses during spruce budworm outbreaks. Further research is warranted to elucidate the mechanism involved, but our working hypothesis is that greater hardwood content increased the diversity or populations of natural enemies such as birds and parasitoids.

Prescribed Burning for Stand Conversion in Budworm-killed Balsam Fir: An Ontario Case History

1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae
Keyword(s):  
Fuel Consumption ◽  
Prescribed Burning ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Fire Spread ◽  
Fire Effects ◽  
Balsam Fir ◽  
Prescribed Burn ◽  
Stand Conversion

Recent spruce budworm (Choristoneura fumiferana [Clem.]) infestations have resulted in widespread areas of balsam fir (Abies balsamea [L.] Mill.) mortality in Ontario, and there is growing interest in reestablishing these areas quickly as productive forests. One technique being used is prescribed fire after a salvage and bulldozer tramping operation. A 445-ha prescribed burn was carried out under moderate fire danger conditions in northern Ontario. The site, which was covered by balsam fir fuel that had been killed by spruce budworm, was tramped to improve fire spread. Weather, fuel consumption, and fire effects are reported. The burn effectively reduced heavy surface fuel loadings and consequently planting on the site was easier. Key words: Prescribed burning, fire, spruce budworm. Choristoneura fumiferana, balsam fir, Abies balsamea, fuel consumption, site preparation, tramping, stand conversion.

Sign in / Sign up

Export Citation Format

Share Document