OVERWINTERING SPRUCE BUDWORM ON BLACK SPRUCE: SAMPLE-UNIT SIZE AND POPULATION DISTRIBUTION

1985 ◽  
Vol 117 (4) ◽  
pp. 395-399 ◽  
Author(s):  
Daniel J. Robison ◽  
Lawrence P. Abrahamson ◽  
Miroslaw M. Czapowskyj ◽  
Edwin H. White ◽  
Douglas C. Allen
Keyword(s):  
Population Distribution ◽  
Black Spruce ◽  
Branch Length ◽  
Spruce Budworm ◽  
Unit Size ◽  
Optimum Size ◽  
Sample Unit ◽  
Larval Distribution ◽  
Total Branch Length ◽  
Branch Distribution

AbstractOptimum size of a sample unit and within-branch distribution of overwintering spruce budworm were determined for black spruce in northern Maine. No significant differences in sample reliability were found between whole-branch and 45-cm branch-tip samples. Larval distribution on branches varied with total branch length and a model was developed to estimate the whole-branch population from a 45-cm branch tip. Use of a 45-cm branch-tip sample unit is recommended because it is biologically and statistically valid and reduces sampling costs.

Distribution of epicormic branches and foliage on Douglas-fir as influenced by adjacent canopy gaps

2018 ◽  
Vol 48 (11) ◽  
pp. 1320-1330
Author(s):  
John W. Punches ◽  
Klaus J. Puettmann
Keyword(s):  
Branch Length ◽  
Canopy Gaps ◽  
Douglas Fir ◽  
Canopy Gap ◽  
Tree Age ◽  
Gap Size ◽  
Terminal Bud ◽  
Total Branch Length ◽  
A Minor ◽  
Epicormic Branches

The influence of adjacent canopy gaps on spatial distribution of epicormic branches and delayed foliage (originating from dormant buds) was investigated in 65-year-old coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco). Sample trees were selected across a broad range of local densities (adjacent canopy gap sizes) from a repeatedly thinned stand in which gaps had been created 12 years prior to our study. Lengths and stem locations of original and epicormic branches were measured within the south-facing crown quadrant, along with extents to which branches were occupied by sequential (produced in association with terminal bud elongation) and (or) delayed foliage. Epicormic branches, while prevalent throughout crowns, contributed only 10% of total branch length and 2% of total foliage mass. In contrast, delayed foliage occupied over 75% of total branch length, accounted for nearly 39% of total foliage mass, and often overlapped with sequential foliage. Canopy gap size did not influence original or epicormic branch length or location. On original branches, larger gaps may have modestly negatively influenced the relative extent of sequential foliage on branches and (or) slightly positively influenced delayed foliage mass. Delayed foliage appears to contribute substantially to Douglas-fir crown maintenance at this tree age, but canopy gap size had a minor influence, at least in the short term.

scholarly journals Control of Insect Damage to Black Spruce Seed Cones with Neem

1997 ◽  
Vol 14 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Barry C. Kostyk ◽  
Kevin W. Wanner
Keyword(s):  
Black Spruce ◽  
Spruce Budworm ◽  
Female Flower ◽  
Seed Extract ◽  
Insect Damage ◽  
Neem Seed ◽  
Flower Abortion ◽  
Lepidopteran Larvae ◽  
Two Stages ◽  
Neem Seed Extract

Abstract A neem seed extract was applied to black spruce trees at two stages of reproductive development to control insect damage to the seed cones. Applied after pollination, neem had no effect on damage by the spruce cone maggot but did provide some protection against defoliation by the spruce budworm. Neem had no effect on the numbers of spruce budworm larvae for the first 9 days of the experiment, but after 23 days, populations declined on trees with two of three neem treatments compared to control trees. Neem reduced cone grazing damage by lepidopteran larvae when applied during the flowering stage. However, increased female flower abortion also resulted. The application of neem seed extract for controlling spruce budworm damage appears promising, but more information is needed on earlier applications in the field to determine if this product could be used operationally without causing substantial flower abortion. North. J. Appl. For. 14(1):40-43.

scholarly journals Sample Sizes Required To Estimate Defoliation of Spruce and Balsam Fir Caused by Spruce Budworm Accurately

1998 ◽  
Vol 15 (3) ◽  
pp. 135-140 ◽  
Author(s):  
David A. MacLean ◽  
Wayne E. MacKinnon
Keyword(s):  
Black Spruce ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Sample Sizes ◽  
Preliminary Assessment ◽  
Travel Costs ◽  
Host Trees ◽  
Sampling Protocols ◽  
Spruce Stands ◽  
Number Of Branches

Abstract Data from the assessment of current defoliation levels on 172,000 individual shoots from 6890 midcrown branches sampled from balsam fir and spruce stands were used to define sampling protocols for assessing defoliation caused by spruce budworm. The method was based on sampling one midcrown branch from each of x host trees per stand, and assessing defoliation of y individual shoots per branch. Both the number of shoots per branch and the number of branches required per stand varied with host species (balsam fir, white spruce, or red-black spruce) and with average defoliation level. Sample sizes required to estimate mean defoliation with 90% confidence that the confidence interval is ±10% ranged from 7 to 24 branches per stand and from 17 to 58 shoots per branch, with the largest samples required at moderate (31-70%) defoliation levels. Estimated costs of shoot and branch sampling and processing ranged from $40-110/stand, based on a 90% confidence level salary rate of $12(Can.)/hr, and excluding travel costs. Results can be applied using a preliminary assessment to determine the general defoliation level, which along with species, determines the required sample size. North. J. Appl. For. 15(3):135-140.

Selection of flood-resistant and susceptible seedlings of Populustrichocarpa Torr. & Gray

1988 ◽  
Vol 18 (2) ◽  
pp. 271-275 ◽  
Author(s):  
Barbara A. Smit
Keyword(s):  
Leaf Area ◽  
Marked Reduction ◽  
Branch Length ◽  
Stomatal Resistance ◽  
Growth And Survival ◽  
Seed Collection ◽  
Individual Leaf ◽  
Total Branch Length ◽  
Collection Sites ◽  
Selection Of

To identify Populustrichocarpa plants with contrasting levels of resistance to flooding, seedlings from five diverse riparian sites were evaluated for growth and survival under flooding conditions. All seedlings survived 6 or 8 weeks of flooding. Total branch length and leaf number were reduced in all flooded plants relative to nonflooded controls. There was also a marked reduction in individual leaf area and increased stomatal resistance of flooded plants compared with nonflooded controls. Growth of flooded and nonflooded plants was highly variable within populations and no significant trends were found among populations. Therefore differential responses to flooding can be selected for within any of the seed collection sites. Plants that were rated as particularly resistant or susceptible fo flooding were selected for further study.

Salvage logging during spruce budworm outbreaks increases defoliation of black spruce regeneration

2018 ◽  
Vol 430 ◽  
pp. 421-430 ◽  
Author(s):  
Anne Cotton-Gagnon ◽  
Martin Simard ◽  
Louis De Grandpré ◽  
Daniel Kneeshaw
Keyword(s):  
Black Spruce ◽  
Spruce Budworm ◽  
Salvage Logging

scholarly journals On Asymptotics of the Beta Coalescents

2014 ◽  
Vol 46 (2) ◽  
pp. 496-515 ◽  
Author(s):  
Alexander Gnedin ◽  
Alexander Iksanov ◽  
Alexander Marynych ◽  
Martin Möhle
Keyword(s):  
Asymptotic Expansions ◽  
Branch Length ◽  
Wasserstein Distance ◽  
Stable Limit ◽  
Initial Number ◽  
Stable Law ◽  
Total Branch Length ◽  
Coalescent Tree ◽  
Number Of Particles

We show that the total number of collisions in the exchangeable coalescent process driven by the beta (1, b) measure converges in distribution to a 1-stable law, as the initial number of particles goes to ∞. The stable limit law is also shown for the total branch length of the coalescent tree. These results were known previously for the instance b = 1, which corresponds to the Bolthausen-Sznitman coalescent. The approach we take is based on estimating the quality of a renewal approximation to the coalescent in terms of a suitable Wasserstein distance. Application of the method to beta (a, b)-coalescents with 0 < a < 1 leads to a simplified derivation of the known (2 - a)-stable limit. We furthermore derive asymptotic expansions for the moments of the number of collisions and of the total branch length for the beta (1, b)-coalescent by exploiting the method of sequential approximations.

Black spruce decline triggered by spruce budworm at the southern limit of lichen woodland in eastern Canada

2001 ◽  
Vol 31 (12) ◽  
pp. 2160-2172 ◽  
Author(s):  
Martin Simard ◽  
Serge Payette
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Jack Pine ◽  
Growth Patterns ◽  
Balsam Fir ◽  
Eastern Canada ◽  
Southern Limit ◽  
Epiphytic Lichen ◽  
Spruce Decline

Black spruce (Picea mariana (Mill.) BSP) is the dominant tree species of the southernmost (48°N) lichen woodlands in eastern Canada. Most spruce trees in mature lichen woodlands appear to be declining, as shown by the massive invasion of the epiphytic lichen Bryoria on dead branches of dying trees. A dendroecological study was undertaken to identify the main causal factors of the decline. A decline index based on the abundance of Bryoria on spruce trees was used to distinguish healthy from damaged lichen–spruce woodlands and to select sampling sites for tree-ring measurements. Three conifer species (black spruce, balsam fir (Abies balsamea (L.) Mill.), and jack pine (Pinus banksiana Lamb.)) were sampled to compare their growth patterns in time and space. In the late 1970s and mid-1980s, black spruce and balsam fir experienced sharp and synchronous radial-growth reductions, a high frequency of incomplete and missing rings, and mass mortality likely caused by spruce budworm (Choristoneura fumiferana (Clem.)) defoliation. Jack pine, a non-host species, showed no such trend. Because black spruce layers were spared, lichen woodlands will eventually regenerate unless fire occurs in the following years. Black spruce decline can thus be considered as a normal stage in the natural dynamics of the southern lichen woodlands.

Effets de la coupe à blanc et de la coupe par bandes sur la régénération obtenue après 5 ans dans des pessières noires du Québec

1995 ◽  
Vol 25 (2) ◽  
pp. 329-342 ◽  
Author(s):  
Pierre Pominville ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Spruce Budworm ◽  
Lower Proportion ◽  
The Other ◽  
Balsam Fir ◽  
Clear Cutting ◽  
Other Hand ◽  
The One ◽  
Almost All ◽  
Coupe À Blanc

An experiment was conducted to compare the effects of traditional clear-cutting with those of strip cutting on regeneration of black spruce, Piceamariana (Mill.) B.S.P., stands on scarified and unscarified uplands and on lowlands. To that effect, regeneration surveys were done before cutting, in the following year, and 3 and 5 years after cutting. Five years after harvesting, strip cutting led to higher coniferous stocking than clear-cutting on scarified uplands and on lowlands. On unscarified uplands, the gain attributable to strip cutting was not significant. The coniferous stocking of strip cuts on scarified uplands was not greater than on unscarified uplands. So the efficiency of scarification could not be proved in that study. Stocking obtained after 5 years remained closely related to the one observed immediately after harvesting in the strip cufs as in the clear-cuttings. This is particularly true for balsam fir, Abiesbalsamea (L.) Mill. In the strip cuts, the balsam fir stocking was constant while the one of black spruce increased. This could have an impact on the evolution of the composition of the new stands and, consequently, on their vulnerability to spruce budworm, Choristoneurafumiferana (Clem.). The majority of the clear-cuttings were well regenerated 5 years after harvesting. Their average coniferous stocking was slightly above 60%. However, 48% of the clear-cuttings did not reach this level when only unscarified plots on uplands were considered. Advance growth was abundant in those plots but suffered high losses during harvesting. Consequently, reducing the losses during harvesting would result in a lower proportion of clear-cuttings with insufficient coniferous stocking 5 years after cutting. On the other hand, almost all the strip cuts with insufficient regeneration after harvesting were well regenerated 5 years later. Thus, strip cutting could be an interesting option on sites with insufficient advance growth and on sites well regenerated before cutting but where important losses during harvesting are anticipated.

Sign in / Sign up

Export Citation Format

Share Document