scholarly journals Changes in hemlock looper [Lepidoptera: Geometridae] pupal distribution through a 3-year outbreak cycle

2005 ◽  
Vol 82 (2) ◽  
pp. 57-63 ◽  
Author(s):  
C. Hébert ◽  
L. Jobin ◽  
R. Berthiaume ◽  
C. Coulombe ◽  
A. Dupont
Keyword(s):  
Balsam Fir ◽  
Monitoring Networks ◽  
Breast Height ◽  
Anticosti Island ◽  
Hemlock Looper

The hemlock looper, Lambdina fiscellaria, pupal distribution was studied through a 3-year outbreak cycle near Lac Princeton on Anticosti Island in Quebec. Over the 3 years, 10 balsam fir trees were cut and all pupae were counted on the stem and branches (non-foliated vs foliated parts) of the lower, middle and upper crowns and on the stem below crown. In pre-outbreak conditions, pupae were mostly found on branches of the middle and upper crowns. During the outbreak, pupal density did not increase on these parts of the trees, since pupae were mostly found on the stem, from the ground to the middle crown, and on branches of the lower crown. Few pupae were found on the foliated portion of branches in post-outbreak conditions but most were found on the basal non-foliated part of branches, which appears to be a preferred location for hemlock looper pupation. In order to optimize detection of population increases in monitoring networks, we suggest using pupal traps at breast height on balsam fir trees.

Boreal peatland margins as repository sites of long-term natural disturbances of balsam fir/spruce forests

2009 ◽  
Vol 71 (3) ◽  
pp. 295-306 ◽  
Author(s):  
Martin Lavoie ◽  
Louise Filion ◽  
Élisabeth C. Robert
Keyword(s):  
Forest Fires ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Natural Disturbances ◽  
Spruce Forests ◽  
Disturbance Factor ◽  
Pollen Concentrations ◽  
Anticosti Island ◽  
Hemlock Looper

AbstractA multidisciplinary, high-resolution paleoecological study (Lepidoptera and plant remains, macroscopic charcoal, pollen) was conducted on a 4000-yr peat monolith extracted from the margin of an ombrotrophic peatland on Anticosti Island (Gulf of St. Lawrence, eastern Canada) to reconstruct the long-term natural disturbances (insect outbreaks, forest fires) of a balsam fir/spruce forest. We hypothesized that an activity of insect defoliators (spruce budworm, hemlock looper) was the main disturbance factor of conifer forests during the Late Holocene. The earliest remains of spruce budworm and hemlock looper were found ca. 3220 and 2350 cal yr BP, respectively. Peaks of insect head capsules occurred from ca. 1640 to ca. 625 cal yr BP. Low balsam fir pollen concentrations during this period suggest a lengthy episode (∼ 1000 yr) of high insect activity, resulting in extensive fir dieback and mortality. The long-term dynamics of the pristine balsam fir/spruce forests were mainly governed by the activity of insect defoliators. The limited extent and possibly the low occurrence of forest fires in the maritime environment of Anticosti Island allowed the development of mature coniferous stands propitious for insect infestations. Insect head capsules appeared to be a useful and effective tool for establishing insect presence and activity during the Holocene.

Winter habitat selection by white-tailed deer on Anticosti Island 2: relationship between deer density from an aerial survey and the proportion of balsam fir forest on vegetation maps

2004 ◽  
Vol 82 (4) ◽  
pp. 671-676 ◽  
Author(s):  
François Potvin ◽  
Barry Boots
Keyword(s):  
Habitat Management ◽  
Abies Balsamea ◽  
Window Size ◽  
Aerial Survey ◽  
Balsam Fir ◽  
Winter Habitat ◽  
Deer Density ◽  
Vegetation Maps ◽  
Anticosti Island ◽  
The Relationship

Determining at what scale to operate and how much cover is needed are important questions for winter habitat management of white-tailed deer, Odocoileus virginianus (Zimmermann, 1780), through logging. We used binary cover maps (reclassified forest vegetation maps) and windows of different sizes (0.2 km × 0.2 km, 0.5 km × 0.5 km, 1 km × 1 km, 2 km × 2 km, and 3 km × 3 km) to describe the relationship between deer density from an aerial survey and the proportion of balsam fir, Abies balsamea (L.) P. Mill., forest (BF) cover in a 270-km2 block on Anticosti Island, Quebec. Maximum white-tailed deer densities reached were quite similar (31–34 deer/km2) irrespective of window size, except for the 3 km × 3 km window for which maximum density remained half lower. Density increased with the amount of BF cover and then reached a plateau above 60% or 70% (two smaller windows) or decreased above 50% or 60% (1 km × 1 km and 2 km × 2 km windows). Results confirm goals previously used for habitat management of deeryards. This new method allows greater flexibility in research applications for describing density–cover relationships because both scale and proportion of cover can be analysed simultaneously.

scholarly journals Coefficients de distribution de la régénération, cinq ans après des coupes avec protection des petites tiges marchandes appliquées dans des sapinières et des pessières noires du Québec

2011 ◽  
Vol 87 (05) ◽  
pp. 669-683 ◽  
Author(s):  
Martin Riopel ◽  
Jean Bégin ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Annual Rainfall ◽  
Deciduous Species ◽  
Partial Cutting ◽  
Coniferous Species ◽  
Breast Height ◽  
Silvicultural Treatments ◽  
Heavy Equipment

For certain mature forests dominated by balsam fir (Abies balsamea [L.] Mill.) or black spruce (Picea mariana [Mill.] BSP), it may be preferable to harvest trees with diameter at breast height greater than 15 cm while conserving smaller ones. This treatment, called harvesting with protection of small merchantable trees, produces strips, where partial cutting is applied, alternating with corridors, which are disturbed by heavy equipment during harvesting. This project studied stocking levels five years after treatment on 4896 sub-plots of 4 m2 in 22 blocks. Stocking coefficients (SC) for coniferous and deciduous species were modeled in order to identify variables affecting stocking. The strips had well-distributed coniferous regeneration, while SC in the corridors were more variable and lower, occasionally less than 60%. Black spruce-dominated sites were not as well stocked as balsam fir-dominated sites. Stocking levels of protected coniferous merchantable trees positively influence coniferous and deciduous SC in the corridors. The presence of coniferous species is also affected by harvest season and total annual rainfall. Alternative silvicultural treatments applicable in certain corridors are presented.

scholarly journals EFFECTS OF DEFOLIATION BY SPRUCE BUDWORM (CHORISTONEURA FUMIFERANA CLEM.) ON RADIAL GROWTH AT BREAST HEIGHT OF BALSAM FIR (ABIES BALSAMEA (L.) MILL.) AND WHITE SPRUCE (PICEA GLAUCA (MOENCH) VOSS.)

1958 ◽  
Vol 34 (1) ◽  
pp. 39-47 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Picea Glauca ◽  
Radial Growth ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
First Year ◽  
Growth Ratio ◽  
Breast Height

The relationship between spruce budworm defoliation and radial growth at breast height for balsam fir and white spruce trees of merchantable size was studied in various stands in northwestern Ontario. Defoliation was recorded yearly for these stands from the beginning of the infestation, and radial growth measurements were obtained from increment cores. The first year of radial growth suppression was calculated by comparing the growth of the affected species with that of jack pine and red pine trees by means of a growth-ratio technique. Apparent suppression in balsam fir and white spruce varied between stands, and, generally, occurred at the earliest in the second year and at the latest in the fourth year of severe defoliation. A wide ring at the base of the tree coinciding with the first year of suppression as reported by Craighead was non-existent.

SAMPLING WESTERN HEMLOCK LOOPER PUPAE (LEPIDOPTERA: GEOMETRIDAE) USING BURLAP TRAPS

1989 ◽  
Vol 24 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Terry L. Shore
Keyword(s):  
Sample Size ◽  
Surface Area ◽  
Significant Relationship ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Tree Diameter ◽  
Breast Height ◽  
Western Hemlock Looper ◽  
Lambdina Fiscellaria Lugubrosa ◽  
Hemlock Looper

Burlap wrapped around western hemlock, Tsuga heterophylla (Raf.) Sarg., trees at breast height was used to trap pupae of the western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst). The number of pupae in the traps was highly variable and was not related to tree diameter or the surface area of the trap. There was a significant relationship between the number of viable pupae per trap and the number of healthy western hemlock looper eggs subsequently laid on lichen in the trees. Sample size requirements are presented.

A new standard pupation shelter for sampling pupae and estimating mortality of the hemlock looper (Lepidoptera: Geometridae)

2004 ◽  
Vol 136 (6) ◽  
pp. 879-887 ◽  
Author(s):  
Christian Hébert ◽  
Luc Jobin ◽  
Richard Berthiaume ◽  
Jean-François Mouton ◽  
Alain Dupont ◽  
...  
Keyword(s):  
Population Abundance ◽  
Breast Height ◽  
Late Instar ◽  
Band Method ◽  
Hemlock Looper

AbstractA new standard pupation shelter for sampling hemlock looper (Lambdina fiscellaria) pupae is described and compared with the burlap band method developed by Otvos (1974; The Canadian Entomologist106: 329–31). The new pupation shelter is placed on the bole, at breast height or in the crown, to estimate population abundance and mortality. The utilization of two shelters at breast height was as efficient as the use of burlap bands to estimate hemlock looper abundance and more efficient for sampling braconid cocoons. It provided reliable estimates of braconid and tachinid parasitism but overestimated that by ichneumonids. This new pupation shelter is an inexpensive tool that can be used easily by nonspecialized personnel, thus allowing increases in the number of sample plots, which is necessary to improve detection of outbreaks of the hemlock looper. This new shelter could be used to sample other lepidopterans whose late-instar larvae aggregate in concealed pupation sites.

Effets de l'élagage sur la résistance électrique cambiale de la tige de jeunes Sapins baumiers

1988 ◽  
Vol 18 (12) ◽  
pp. 1655-1658 ◽  
Author(s):  
Robert R. Gagnon ◽  
Michel Chabot ◽  
Marius Pineau
Keyword(s):  
Electrical Resistance ◽  
Physiological Significance ◽  
Balsam Fir ◽  
Clear Cut ◽  
Breast Height ◽  
Advanced Regeneration ◽  
Factors Influencing ◽  
Tree Stem

In the spring of 1985, 125 young balsam fir trees (Abiesbalsamea (L.) Mill.) originating from advanced regeneration following a clear-cut in 1970 were pruned to live crown ratios of 0.6, 0.4, 0.2 and 0.0 as compared with control trees which had naturally developped a live crown ratio of 0.8. Subsequently, the cambial electrical resistance of these trees was measured at breast height 17 times between June and October. Ten days after pruning, there was a decrease in cambial electrical resistance. Relating these results to factors influencing the movement of water through the tree leads to a better understanding of the physiological significance of tree stem cambial electrical resistance.

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