The Impact of Balsam Woolly Aphid Damage on Balsam Fir Stands in Newfoundland

1975 ◽  
Vol 5 (2) ◽  
pp. 195-209 ◽  
Author(s):  
G. Page
Keyword(s):  
Basal Area ◽  
Control Measures ◽  
Balsam Fir ◽  
Moisture Regime ◽  
Soil Moisture Regime ◽  
Woolly Aphid ◽  
Stand Height ◽  
Hazard Rating ◽  
Mature Stands ◽  
The Impact

This paper presents data on the effects of balsam woolly aphid damage on the mensurational characteristics of balsam fir trees and stands, and quantitative estimates of changes in merchantable volumes that result from alterations in these characteristics. Average volume losses in damaged semi-mature and mature stands ranged from 2 to 6%, but were as high as 80% or more in a few highly susceptible stands. Strong and consistent relationships were recorded between the incidence and severity of aphid damage and a number of site and stand characteristics, including elevation, soil-moisture regime, stand height and age, balsam fir content and total balsam fir basal area of affected stands, and length of time damage had been present. These relationships were utilized to construct a hazard-rating system for use by forest managers in identifying sites and stands highly susceptible to severe damage, and in scheduling silvicultural control measures.

The impact of climate change on the soil/moisture regime of Scottish mineral soils

1994 ◽  
Vol 83 (1-2) ◽  
pp. 245-250 ◽  
Author(s):  
A.M. MacDonald ◽  
K.B. Matthews ◽  
E. Paterson ◽  
R.J. Aspinall
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Moisture Regime ◽  
Impact Of Climate Change ◽  
Soil Moisture Regime ◽  
Mineral Soils ◽  
The Impact

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

scholarly journals Deadwood Characteristics in Mature and Old-Growth Birch Stands and Their Implications for Carbon Storage

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 536 ◽  
Author(s):  
Silva Šēnhofa ◽  
Ieva Jaunslaviete ◽  
Guntars Šņepsts ◽  
Jurģis Jansons ◽  
Līga Liepa ◽  
...  
Keyword(s):  
Basal Area ◽  
High Volume ◽  
Stand Age ◽  
Old Growth ◽  
Stand Productivity ◽  
Stand Type ◽  
The Difference ◽  
Mineral Soils ◽  
Stand Height ◽  
Mature Stands

As one of the most abundant tree species in the hemiboreal zone, birch is important from both commercial and biodiversity perspectives. While old-growth deciduous stands are important for biodiversity conservation with an emphasis on deadwood availability, the role that deadwood in these stands plays in carbon sequestration remains unclear. We studied mature (71–110 years old) and old-growth (121–150 years old) birch stands on fertile mineral soils. The marginal mean deadwood volume was 43.5 ± 6.4 m3 ha−1 in all mature stands, 51.3 ± 7.1 m3 ha−1 in recently unmanaged mature stands, and 54.4 ± 4.4 m3 ha−1 in old-growth stands; the marginal mean deadwood carbon pool for each stand type was 5.4 ± 0.8 t·ha−1, 6.3 ± 0.9 t·ha−1, and 7.9 ± 0.6 t·ha−1, respectively. Deadwood volume was not related to stand productivity in terms of stand basal area, stand height, or stand age. The difference between mature and old-growth stands remained non-significant (p < 0.05). A high volume of deadwood was almost continuously present throughout the landscape in assessed unmanaged sites; moreover, 88% of sample plots in old-growth stands and 63% of sample plots in mature stands had a deadwood volume higher than 20 m3·ha−1. Old-growth stands had a slightly greater volume of large deadwood than unmanaged mature stands; in both, almost half of the deadwood was more than 30 cm in diameter and approximately one-fifth had a diameter greater than 40 cm. Both groups of stands had similar proportions of coniferous and deciduous deadwood and lying and standing deadwood. Old-growth stands had a higher volume of recently and weakly decayed wood, indicating increased dieback during recent years.

scholarly journals THE INFLUENCE OF BIOLOGICAL ADDITIVES ON THE MOISTURE RETENTION OF SOIL

2018 ◽  
Author(s):  
Inga ADAMONYTĖ ◽  
Vilda GRYBAUSKIENĖ ◽  
Gitana VYČIENĖ
Keyword(s):  
Soil Moisture ◽  
Raw Materials ◽  
Moisture Regime ◽  
Moisture Retention ◽  
Critical Temperatures ◽  
Soil Moisture Regime ◽  
Moisture Variation ◽  
Berry Crops ◽  
The Impact ◽  
Soil Moisture Retention

With the onset of climate change, dry periods are more frequent, and therefore the rational use of naturally accumulating soil moisture can be a tool to regulate the unfavourable soil moisture regime. Demand for new biological materials is increasing rapidly with the development of biotechnological science. Superabsorbent or water retaining material is considered promising material that is widely used in the fields of industry and agriculture. These can both absorb large amounts of water, as much as hundreds of times their own mass. The use of biological environmentally friendly additives to the cultivation of agricultural products, particularly germination and rooting periods, can ensure the required moisture content of the soil. The use of additives is more economical growing relatively more expensive raw materials, so in most cases it is related to vegetable and berry crops. The aim is to investigate the extent to which biological additives can absorb and give back moisture, assessing the different incorporation relations, as well as different biological additives. Soil moisture variation for samples with embedded biological additives ended after 24 and 26 days under laboratory conditions at 17 and 19 °C; it ended after 15 days in an environmental chamber at 20 °C. On average, soil moisture retention increases by 14 days more than the control without additives. The results showed that at low temperatures all the biological additives considered help to keep the moisture available to the plants longer in the soil for approximately the same number of days. In assessing these results, it should be emphasized that the conditions in the nature are different from the simulated critical temperatures and without the addition of moisture, in the natural conditions the impact of biological additives will be longer.

scholarly journals Impact of a spruce budworm outbreak in balsam fir and subsequent stand development over a 40-year period

2008 ◽  
Vol 84 (1) ◽  
pp. 60-69 ◽  
Author(s):  
David A MacLean ◽  
Allison R Andersen
Keyword(s):  
Stand Structure ◽  
Abies Balsamea ◽  
Basal Area ◽  
Stand Density ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Stand Development ◽  
Wide Range ◽  
Break Up ◽  
The Impact

Nine 0.04-ha plots were established in 1956 (age 35 years) in a balsam fir (Abies balsamea [L.] Mill.) stand in northwestern New Brunswick, Canada to determine the impact of an uncontrolled spruce budworm (Choristoneura fumiferana [Clem.]) outbreak on stand development. The plots were measured annually from 1956 to 1961 and at five-year intervals from 1965 to 1995. Moderate to severe defoliation occurred from 1951 to 1957 and again in 1975 to 1977, 1981, and 1986 to 1988. Budworm-caused mortality from 1956 to 1961 (age 35 to 40 years) varied considerably among plots, reducing volume by 35 to 113 m3/ha (34%-84%), and resulting in a wide range of post-outbreak plot densities. Plots were grouped into three post-budworm outbreak (1965, age 45 years) basal area classes, of ≤ 20 m2/ha, 21 to 27 m2/ha, and ≥ 28 m2/ha, to examine stand recovery. Recovery of volume up to age 60 years ranged from 72 to 132 m3/ha, in the lowest to highest basal area classes, respectively. From age 60 to 75 years, five plots declined in volume due to the onset of stand break-up and four plots increased in volume. By age 60 years, survivor growth was greatest in the high basal area plots, ranging from 6.2 to 9.0 m3/ha/yr in seven plots, versus 2.6 to 3.2 m3/ha/yr in two low basal area plots. From age 60 to 75 years, survivor growth averaged only 2.8 to 5.2 m3/ha/yr, and the stand exhibited major decline, with 63%, 74%, and 78% mortality of fir ≤ 15 cm DBH in the low to high basal area plots, respectively. Budworm-caused "thinning" in the 1950s largely determined subsequent stand development and the rate of stand break-up 25 to 35 years later. The timing and rate of natural stand decline was strongly influenced by post-outbreak stand density. Key words: budworm-caused mortality, stand structure, stand development, growth, mortality, stand density

Influence du drainage et de la texture du dépôt sur la vulnérabilité du Sapin baumier et de l'Épinette blanche aux attaques de la Tordeuse des bourgeons de l'épinette

1990 ◽  
Vol 20 (6) ◽  
pp. 750-756 ◽  
Author(s):  
Louis Archambault ◽  
Robert R. Gagnon ◽  
Georges Pelletier ◽  
Michel Chabot ◽  
Louis Bélanger
Keyword(s):  
Soil Moisture ◽  
Pest Management ◽  
Soil Texture ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Moisture Regime ◽  
Soil Moisture Regime ◽  
Ecosystem Classification ◽  
Spruce Mortality

Balsam fir (Abiesbalsamea (L.) Mill.) and white spruce (Piceaglauca (Moench) Voss) mortality was measured in five areas of the province of Quebec severely affected by spruce budworm (Choristoneurafumiferana (Clem.)) defoliation. Mortality was compared for different combinations of soil texture and drainage. For balsam fir, two vulnerability classes, based on combinations of soil texture and drainage, were defined. In the first class, mortality reached 74% of the preoutbreak volume, as compared with 86% in the second class. For white spruce, three vulnerability classes were defined based on soil texture and drainage combinations. In the low, moderate, and high vulnerability classes, white spruce mortality reached 10, 26, and 52%, respectively. Soil moisture regime is an important factor in determining vulnerability. From these results, we propose an ecosystem classification based on vulnerability to spruce budworm. Particular reference is made to what significance the findings may have for forest integrated pest management.

The methodological approach for the determination of the pressure of artificial raindrops as a question of the theory of splash soil erosion

2020 ◽  
pp. 24-28
Author(s):  
Mihail Zver'kov
Keyword(s):  
Block Diagram ◽  
Methodological Approach ◽  
Control Measures ◽  
Soil Conditions ◽  
Effective Pressure ◽  
Long Distance ◽  
Splash Erosion ◽  
Rain Drops ◽  
Artificial Rain ◽  
The Impact

To the article the results of the theoretical and experimental researches are given on questions of estimates of the dynamic rate effect of raindrop impact on soil. The aim of this work was to analyze the current methods to determine the rate of artificial rain pressure on the soil for the assessment of splash erosion. There are the developed author’s method for calculation the pressure of artificial rain on the soil and the assessment of splash erosion. The study aims to the justification of evaluation methods and the obtaining of quantitative characteristics, prevention and elimination of accelerated (anthropogenic) erosion, the creation and the realization of the required erosion control measures. The paper considers the question of determining the pressure of artificial rain on the soil. At the moment of raindrops impact, there is the tension in the soil, which is called vertical effective pressure. It is noted that the impact of rain drops in the soil there are stresses called vertical effective pressure. The equation for calculation of vertical effective pressure is proposed in this study using the known spectrum of raindrops. Effective pressure was 1.4 Pa for the artificial rain by sprinkler machine «Fregat» and 5.9 Pa for long distance sprinkler DD-30. The article deals with a block diagram of the sequence for determining the effective pressure of rain drops on the soil. This diagram was created by the author’s method of calculation of the effective pressure of rain drops on the soil. The need for an integrated approach to the description of the artificial rain impact on the soil is noted. Various parameters characterizing drop erosion are considered. There are data about the mass of splashed soil in the irrigation of various irrigation machinery and installations. For example, the rate (mass) of splashed soil was 0.28…0.78 t/ha under irrigation sprinkler apparatus RACO 4260–55/701C in the conditions of the Ryazan region. The method allows examining the environmental impact of sprinkler techniques for analyzes of the pressure, caused by raindrops, on the soil. It can also be useful in determining the irrigation rate before the runoff for different types of sprinkler equipment and soil conditions.

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