Croissance juvénile de marcottes d'épinette noire en régénération après récolte du couvert dominant

1993 ◽  
Vol 23 (7) ◽  
pp. 1396-1401 ◽  
Author(s):  
Jocelyn Boily ◽  
René Doucet
Keyword(s):  
Growth Rates ◽  
Natural Regeneration ◽  
Black Spruce ◽  
Height Growth ◽  
Management Unit ◽  
Site Quality ◽  
Clear Cutting ◽  
Ecological Regions ◽  
Spruce Stands ◽  
Stand Height

Annual height growth of natural regeneration was measured in 18- to 21-year-old clear-cuts of black spruce stands growing on sites of contrasted drainage, in two ecological regions of the Haute-Gatineau-et-Cabonga management unit in western Quebec. Most regeneration was established by layering and was growing slowly on all sites at time of release by clear-cutting of the main stand. Height growth rates increased rapidly thereafter on mesic sites: about 7 to 8 years after release, it reached 15 cm or more per year, and 32 to 45 cm per year 20 years after harvest. On moist sites, growth rates of 15 cm per year were attained only 10 to 15 years after release, and did not exceed 25 cm at age 20. These results show that growth of black spruce natural regeneration is controlled more by site quality than by the mechanism responsible for reproduction.

The effect of advance regeneration height on future yield of black spruce stands

1995 ◽  
Vol 25 (4) ◽  
pp. 536-544 ◽  
Author(s):  
David Pothier ◽  
René Doucet ◽  
Jocelyn Boily
Keyword(s):  
Black Spruce ◽  
Site Index ◽  
Site Quality ◽  
Management Tools ◽  
Clear Cutting ◽  
Advance Regeneration ◽  
Short Period ◽  
Index Site ◽  
Spruce Stands ◽  
Stand Height

The advance regeneration often present following clear-cutting in black spruce (Piceamariana (Mill.) B.S.P.) stands is generally composed of individuals of various heights. This initial height difference is hypothesized to affect the yield of the future stand. Height of the advance regeneration at time of release was determined on several black spruce trees within 33 stands distributed across the boreal forest of the province of Quebec, Canada. From these data, a regeneration structure index was developed and used to explain a part of the variation in subsequent stand yield. Dominant trees of stands developing for 38 to 65 years since clear-cutting generally originated from the tallest advance regeneration at time of release. Stands with the tallest regeneration at time of release produced the largest yields for a given site quality and number of years since harvesting. A 3-m increase in advance-regeneration height resulted in a similar yield gain as a 3-m increase in site index. Site indices calculated from age-height relationships of dominant trees originating from tall advance regeneration were less than those calculated from trees that have undergone a relatively short period of suppression. These results suggest that traditional management tools developed for fire-origin black spruce stands, i.e., stands mainly composed of seed-origin trees established after perturbation, should be adjusted for clearcut-origin stands that largely develop from advance regeneration.

Ten-year results of strip clear-cutting in Quebec black spruce stands

2000 ◽  
Vol 30 (1) ◽  
pp. 59-66 ◽  
Author(s):  
David Pothier
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Height Growth ◽  
Clear Cutting ◽  
Advance Regeneration ◽  
Spruce Stands ◽  
Harvesting Method ◽  
Cost Efficient ◽  
One Year ◽  
Cutting System

Regeneration of first-cut strips in a two-cut system of strip clear-cutting was compared to that of large clear-cutting in four different areas representative of the black spruce (Picea mariana (Mill.) BSP) stands of the boreal forest of Quebec. Seedlings were more evenly distributed in clearcut strips than in large clearcuts. Differences of about 10 000 black spruce seedlings per hectare and 20% of stocking were observed in favour of clearcut strips compared to large clearcuts. Black spruce stocking was about 14% larger on lowland than on upland sites but height growth was better on upland sites. A regeneration problem similar to that of large clearcuts was observed when the second strips were cut. One year after cutting these second strips, winter harvesting resulted in a 23% gain in black spruce stocking as compared to summer harvesting. Even if black spruce stocking marginally increased during the years following winter harvesting, the height advantage of the preserved advance growth justifies the application of this harvesting method. The strip clear-cutting system effectively improved the stocking of former black spruce stands but if the stocking level of advance growth is adequate, careful harvesting to preserve advance regeneration should be the preferred method since it would be more cost-efficient.

Croissance en hauteur à long terme de la régénération préétablie dans des pessières noires boréales régénérées par marcottage, au Québec

1992 ◽  
Vol 22 (4) ◽  
pp. 613-621 ◽  
Author(s):  
Raynald Paquin ◽  
René Doucet
Keyword(s):  
Growth Rate ◽  
Black Spruce ◽  
Height Growth ◽  
Growth Patterns ◽  
Dominant Position ◽  
Clear Cutting ◽  
Effective Age ◽  
Second Growth ◽  
Spruce Stands ◽  
To Come

Height-growth patterns of black spruce (Piceamariana (Mill.) B.S.P.) in the boreal forest were studied in layer-origin stands released by clear-cutting in the first half of this century. Most stems responded to release brought about by clear-cutting of the main stand. Initially, small stems responded more rapidly and more strongly, but their height-growth rate culminated between 20 and 30 years following release, the same period when height-growth rate culminated for the taller, older stems. After the culmination period, growth rates were independent of height at the time of release. Consequently, the taller stems at time of release were able to maintain their dominant position. Height growth over the recent years indicates that this position could be maintained in the years to come, and even indefinitely. It seems that second-growth black spruce stands behave like even-aged stands despite their uneven-aged structure. Consequently, years since release and stem height are more accurate measures of stem effective age than total age. Moreover, the taller stems in the understory, which are usually considerably older, should be considered to be as valuable as smaller regeneration when a stand is cut.

scholarly journals A Height Growth Model and Associated Growth Intercept Models for Estimating Site Index in Black Spruce (Picea mariana Mill. B.S.P.) Plantations in Northern Ontario, Canada

2011 ◽  
Vol 28 (3) ◽  
pp. 129-137
Author(s):  
Martin M. Kwiaton ◽  
Jian R. Wang ◽  
Douglas E.B. Reid
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Site Index ◽  
Height Growth ◽  
Growth And Yield ◽  
Site Quality ◽  
Northern Ontario ◽  
Spruce Stands ◽  
Growth Intercept

Abstract Site quality is a key component of growth and yield models because height growth rates are known to be influenced by available site resources. Accurate prediction of future growth and yield requires site quality information for both plantations and natural stands. The forest industry in northern Ontario relies on high-quality wood and fiber from black spruce (Picea mariana Mill. B.S.P.); therefore, these tools are essential to ensure sustainable forest management. Although there are site index (SI) models for natural-origin black spruce stands in northern Ontario, models for estimating site quality of young black spruce plantations have not been developed. We used stem analysis data collected from 62 plantations (>40 years of age) of pure black spruce across northern Ontario to develop height growth, SI, and variable growth intercept models. The distinct height growth patterns we observed may be attributed to early silvicultural treatments (site preparation and herbicide) in plantations allowing black spruce trees to attain breast height (1.3 m) faster than in fire-origin stands in northern Ontario. Our models can be used to estimate site quality of black spruce plantations, a key consideration for silviculture and forest management planning. We also compare our managed stand SI model to one we developed from a comparable subset of data from black spruce growing in unmanaged stands and propose a method to assign an SI with a common base age to pure upland black spruce stands regardless of origin.

scholarly journals Effect of stand edge on the natural regeneration of spruce, beech and Douglas-fir

2012 ◽  
Vol 60 (6) ◽  
pp. 49-56 ◽  
Author(s):  
Lumír Dobrovolný ◽  
T. Štěrba ◽  
J. Kodeš
Keyword(s):  
Natural Regeneration ◽  
Woody Plants ◽  
Height Growth ◽  
Douglas Fir ◽  
Light Conditions ◽  
Climatic Extremes ◽  
Clear Cutting ◽  
Acidic Sites ◽  
To Come ◽  
Stand Height

Our work aimed at studying the strategy of woody plants regeneration during the regeneration of a spruce stand with the admixture of beech and Douglas-fir by border cutting (NW-SE aspect) on acidic sites of higher elevations in the Bohemian-Moravian Upland. Spruce is better adapted to bear shade than Douglas-fir. Nevertheless, in optimal light conditions up to a distance of ca. 35 m (about 16% DIFFSF) from the stand edge, the Douglas-fir can put the spruce into danger as to height growth. By contrast to beech, the density of spruce is significantly higher within the distance of 45 m (about 15% DIFFSF) from the stand edge but further on the situation would change to the benefit of beech. The density of Douglas-fir significantly dominates over beech within a distance of 35 m from the stand edge; from 55 m (less than 15% DIFFSF), the situation changes in favour of beech. Beech can survive in full shade deep in the stand core waiting for its opportunity to come. As compared to spruce and Douglas-fir, the height growth of beech was at all times significantly greater at a distance of 25 m from the stand edge. Converted to practical conditions, spruce and Douglas-fir with individually admixed beech seedlings showed good prosperity approximately up to a distance of one stand height from the edge. A mixture of spruce and beech did well at a greater distance but good prosperity at a distance of 2–3 stand heights was shown only by beech. Thus, border regeneration eliminates disadvantages of the climatic extremes of clear-cutting and specifics of shelterwood felling during which one – usually shade-tolerant tree species dominates in the natural regeneration (e.g. beech).

scholarly journals Comparative Height Growth of Eastern Larch and Black Spruce in Northwestern Ontario

1978 ◽  
Vol 54 (6) ◽  
pp. 296-297 ◽  
Author(s):  
Douglas A. Mead
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Height Growth ◽  
Larix Laricina ◽  
Stem Analysis ◽  
Northwestern Ontario ◽  
Analysis Methods ◽  
Spruce Stands

Height growth of eastern larch (Larix laricina (Du Roi) K. Koch) and black spruce (Picea mariana (Mill.) B.S.P.) was determined using standard stem analysis methods on trees from two sites in northwestern Ontario. The data were obtained from mixed larch-spruce stands which were relatively undisturbed. The larch exhibited substantially better height growth than the spruce through age 65.

scholarly journals A NEW APPROACH TO THE NORTHERN SPRUCE REGENERATION PROBLEM

1954 ◽  
Vol 30 (4) ◽  
pp. 372-379 ◽  
Author(s):  
Henri LeBlanc
Keyword(s):  
Picea Mariana ◽  
Detrimental Effect ◽  
Black Spruce ◽  
New Approach ◽  
Normal Concentration ◽  
Clear Cutting ◽  
Seed Supply ◽  
Spruce Stands ◽  
Intensive Work

Lack of reproduction of black spruce, Picea mariana, in pure black spruce stands in old cut-over areas, has always been a great subject of discussion and one for intensive work among foresters. Many reasons such as the absence of an adequate seed supply stored on top of humus, or adverse germination conditions are said to be partly responsible.This study on the humus of this unregenerated cut-over area, indicates clear cutting of this stand will influence the normal concentration of definite micro-nutrients such as manganese and magnesium.The augmentation of manganese in the soil has a detrimental effect on the growth of plants when, its concentration is too high. The diminution of magnesium, which is an element necessary to stimulate the growth, must create abnormal nutritive conditions of the habitat. This visible lack of equilibrium might be the cause of the absence of seedlings of Picea mariana on certain parts of this cut-over area.

Mechanical stability of black spruce in the clay belt region of northern Ontario

1987 ◽  
Vol 17 (9) ◽  
pp. 1080-1091 ◽  
Author(s):  
V. G. Smith ◽  
M. Watts ◽  
D. F. James
Keyword(s):  
Mechanical Stability ◽  
Black Spruce ◽  
Stand Density ◽  
Tree Height ◽  
Static Force ◽  
Northern Ontario ◽  
Wind Speeds ◽  
Spruce Stands ◽  
Stand Height ◽  
The Stability

Black spruce (Piceamariana (Mill.) B.S.P.) is an important pulpwood species that grows on peatland sites in the clay belt region of northern Ontario. The mechanical stability of spruce found on these sites is crucial in determining how tall a stand can grow before losses due to windthrow become excessive. In this study, the stability of a sample of 58 black spruce trees, in stands of various height and density classes, was measured by winching them over and determining their critical turning moment. Regression analysis was used to express critical turning moment as a function of tree height, dominant stand height, and stand stocking. An analysis was carried out to estimate turning moments due to static wind action on the sample trees and predicting the wind speeds required to produce the static force needed to cause windthrow. A comparison of the measured critical turning moments to the estimated wind-generated critical turning moments was used to identify the wind speeds that have enough static force to cause windthrow. A table of critical wind speeds, based on a reference wind, is given for black spruce stands of various heights and densities. Based on these wind speeds and winds associated with periodic storms, black spruce stands can be expected to become susceptible to windthrow once dominant stand height reaches 20 to 21 m. Stand stability increases with stand density owing to the greater ability of dense stands to dissipate incoming winds and the added stability of interlocking root systems. These results suggest that the black spruce stands growing on peatland sites in the clay belt should be harvested before dominant stand height reaches a maximum of 20 to 21 m to avoid excessive losses due to windthrow.

Mortality of balsam fir and black spruce advance growth 3 years after clear-cutting

1995 ◽  
Vol 25 (9) ◽  
pp. 1528-1537 ◽  
Author(s):  
Jean-Claude Ruel ◽  
René Doucet ◽  
Jocelyn Boily
Keyword(s):  
Logistic Regression ◽  
Black Spruce ◽  
Height Growth ◽  
Seedling Quality ◽  
Balsam Fir ◽  
First Year ◽  
Logging Damage ◽  
Clear Cutting ◽  
Lean Angle ◽  
Logistic Regressions

The effects of balsam fir (Abiesbalsamea (L.) Mill.) and black spruce (Piceamariana (Mill.) B.S.P.) seedling attributes on survival were measured on four cutovers regenerated to black spruce and three regenerated to balsam fir. In each of these, about 240 stems were permanently identified shortly after logging and their main characteristics were noted. Survival was assessed after 1 and 3 years. First-year mortality reached 24% for balsam fir and and 21% for black spruce. It varied with height and seedling quality. Mortality during the second and third year after harvesting was less important and was more evenly distributed between the different height classes. When all height classes were combined, the logistic regression calculated for total balsam fir mortality was able to correctly classify the observations in 74% of the cases by using three variables: prerelease height growth, lean angle, and a wound index. For black spruce, seven variables were needed to correctly classify 78% of the observations. These were: height, prerelease height growth, live crown ratio, lean angle, distance to the straightening point, and two wound indices. Separate logistic regressions were calculated for stems smaller or taller than 30 cm. These regressions performed considerably better for the taller height class for both species. For balsam fir, lean angle and one or another wound index still remained in relation with survival. For black spruce, prerelease height growth and lean angle remained in relation with survival. Distance to the straightening point was only retained for stems below 30 cm while live crown ratio and the two wound indices were retained for stems over 30 cm. These results suggest that an evaluation of seedling quality using measures of previous suppression and logging damage should be introduced in regeneration surveys to better predict the evolution of a cutover after harvesting.

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