Comparing bird assemblages in successional black spruce stands originating from fire and logging

1999 ◽  
Vol 77 (12) ◽  
pp. 1850-1860 ◽  
Author(s):  
Louis Imbeau ◽  
Jean-Pierre L Savard ◽  
Réjean Gagnon

Comparisons of the effects of logging and fire as disturbance agents on the composition of bird assemblages in boreal ecosystems are still lacking or are limited to the short-term impacts of clear-cutting. In Quebec, where the boreal forest is largely dominated by black spruce (Picea mariana (Mill.) B.S.P.) stands, we surveyed 140 point-count stations in 3 postlogging and 4 postfire development stages determined according to the height of the regenerating spruce trees. Species richness did not vary among forest development stages, but bird abundance was higher in recent clearcuts. Recently disturbed areas were characterized by open-land bird assemblages dominated by Neotropical migrants, which reached their highest abundance in clearcuts. Moreover, logged stands were distinguished from burned sites by the absence of cavity-nesting birds. Forest-bird assemblages reestablished themselves as soon as young spruces reached the sapling stage. However, the Black-backed Woodpecker (Picoides arcticus), Three-toed Woodpecker (Picoides tridactylus), and Brown Creeper (Certhia americana) were restricted to mature stands or recent burns and are thus likely to be negatively affected by modern forestry, which involves fire suppression and short logging rotations. We suggest that retention of larger areas of continuous mature forest might be essential to maintain these species in managed regions.

1954 ◽  
Vol 30 (4) ◽  
pp. 372-379 ◽  
Author(s):  
Henri LeBlanc

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.


2000 ◽  
Vol 30 (1) ◽  
pp. 59-66 ◽  
Author(s):  
David Pothier

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.


1992 ◽  
Vol 22 (4) ◽  
pp. 613-621 ◽  
Author(s):  
Raynald Paquin ◽  
René Doucet

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.


2002 ◽  
Vol 32 (3) ◽  
pp. 539-547 ◽  
Author(s):  
Jean-Martin Lussier ◽  
Hubert Morin ◽  
Réjean Gagnon

The mortality pattern of 14 black spruce (Picea mariana (Mill.) BSP) stands from the Saguenay region (Quebec), originating from fire or clear-cutting in the early 20th century, was reconstructed based on the dendrochronological dating of dead trees. Most of the spruces died during the 1970s and 1980s, which suggests the possible impact of the most recent spruce budworm (Choristoneura fumiferana Clem.) outbreak. This hypothesis is supported by the observation of major growth reductions synchronous with known outbreak periods and by the existence of a significant partial correlation between the mortality rates and the occurrence of outbreaks. A significant partial correlation between the mortality rates and the relative density of the studied stands suggests that competition amongst individuals might act as a predisposing factor to the death of trees, while the outbreaks act as an inciting factor. The observed mortality pattern is similar to self-thinning, since most of the dead trees were from the smallest size classes.


1995 ◽  
Vol 25 (4) ◽  
pp. 536-544 ◽  
Author(s):  
David Pothier ◽  
René Doucet ◽  
Jocelyn Boily

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.


1993 ◽  
Vol 23 (7) ◽  
pp. 1396-1401 ◽  
Author(s):  
Jocelyn Boily ◽  
René Doucet

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 Condor ◽  
2016 ◽  
Vol 118 (2) ◽  
pp. 376-390 ◽  
Author(s):  
Erin Bayne ◽  
Lionel Leston ◽  
C. Lisa Mahon ◽  
Péter Sólymos ◽  
Craig Machtans ◽  
...  

1978 ◽  
Vol 54 (6) ◽  
pp. 296-297 ◽  
Author(s):  
Douglas A. Mead

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.


1998 ◽  
Vol 15 (3) ◽  
pp. 135-140 ◽  
Author(s):  
David A. MacLean ◽  
Wayne E. MacKinnon

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.


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