Comparative physiological responses of Rhododendron groenlandicum and regenerating Picea mariana following partial canopy removal in northeastern Quebec, Canada

2010 ◽  
Vol 40 (9) ◽  
pp. 1791-1802 ◽  
Author(s):  
François Hébert ◽  
Nelson Thiffault ◽  
Jean-Claude Ruel ◽  
Alison D. Munson

In boreal black spruce ( Picea mariana (Mill.) BSP) dominated stands, careful logging around advance regeneration contributes to protect the shrub layer while increasing light availability. Therefore, it may promote expansion of bog Labrador tea ( Rhododendron groenlandicum (Oeder) Kron & Judd), which can impair black spruce growth by direct competition for nutrients and by alteration of soil biochemical conditions. Such harvesting approaches may not be suited for irregular, uneven-aged black spruce stands in the context of ecosystem-based management. Our objectives were to evaluate the effects of different intensities of partial harvest on critical resource availability and to compare the physiological and morphological responses of black spruce and Rhododendron to different intensities of partial harvest treatments. Two years after harvest, photosynthesis rate of black spruce was unchanged and was lower than that of Rhododendron, which was 63% higher after harvest. Nitrogen and water use efficiency were, respectively, 171% and 42% higher in Rhododendron than in black spruce after logging. Following harvest, black spruce physiology appeared to be regulated by the atmospheric humidity deficit, but for Rhododendron, physiology was regulated by light availability. The high plasticity of Rhododendron leaf traits could be indicative of the future advantage of this species in these stands following canopy removal associated with harvest.

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.


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.


2004 ◽  
Vol 34 (9) ◽  
pp. 1938-1945 ◽  
Author(s):  
Isobel Waters ◽  
Steven W Kembel ◽  
Jean-François Gingras ◽  
Jennifer M Shay

This study compares the effects of full-tree versus cut-to-length forest harvesting methods on tree regeneration in jack pine (Pinus banksiana Lamb.), mixedwood (Picea glauca (Moench) Voss – Populus tremuloides Michx. – Abies balsamea (L.) Mill.), and black spruce (Picea mariana (Mill.) BSP) sites in southeastern Manitoba, Canada. We surveyed tree regeneration densities, disturbance characteristics, and understorey vegetation in replicated control and harvested plots in each site type preharvest (1993) and 1 and 3 years postharvest (1994, 1996). In jack pine sites, the full-tree harvest method promoted regeneration of Pinus banksiana through increased disturbance of soil and the moss layer, and decreased slash deposition relative to the cut-to-length method. Conversely, in mixedwood sites the cut-to-length method resulted in less damage to advance regeneration and proved better at promoting postharvest regeneration of Abies balsamea and Picea glauca relative to the full-tree method. In black spruce sites, there were few differences in the impact of the two harvesting methods on regeneration of Picea mariana, which increased in frequency and density after both types of harvesting.


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.


1990 ◽  
Vol 68 (4) ◽  
pp. 825-831 ◽  
Author(s):  
Robert L. Doudrick ◽  
Elwin L. Stewart ◽  
Alvin A. Alm

Twenty-two stands of black spruce, Picea mariana (Mill.) B.S.P., in northern Minnesota were surveyed for ectomycorrhizal fungi. Site selection criteria in black spruce stands included geologic history, soil type, stand origin, age, and productivity. Site preference relationships were noted for several of the 46 species of fungi collected during the 2-year study. Twenty-five isolates were tested in aseptic culture for their ability to form ectomycorrhizae with black spruce seedlings. Ectomycorrhizae were produced by Cenococcum sp., Laccaria bicolor (Maire) Orton, Laccaria laccata var. moelleri Singer, Rhizopogon sp., and Suillus cavipes (Opat.) Smith & Thiers.


2007 ◽  
Vol 37 (9) ◽  
pp. 1563-1571 ◽  
Author(s):  
H. C. Thorpe ◽  
S. C. Thomas ◽  
J. P. Caspersen

Variants of partial harvesting are gaining favour as means to balance ecosystem management and timber production objectives on managed boreal forest landscapes. Understanding how residual trees respond to these alternative silvicultural treatments is a critical step towards evaluating their potential from either a conservation or a wood supply perspective. We used dendroecological techniques combined with a chronosequence approach to quantify the temporal radial growth response pattern of residual black spruce ( Picea mariana (Mill.) BSP) trees to partial harvest in northeastern Ontario. At its peak, 8–9 years after harvest, radial growth of residual trees had doubled. The growth pattern was characterized by a 2-year phase of no response, a subsequent period of increase 3–9 years after harvest, and a stage of declining rates 10–12 years after harvest. The magnitude of tree growth response depended strongly on tree age: peak postharvest growth was substantially higher for young trees, while old trees displayed only modest growth increases. Both the large magnitude and the time delay in postharvest growth responses have important implications for the development of more accurate quantitative tools to project future yields and, more generally, for determining whether partial harvesting is a viable management option for the boreal forest.


1998 ◽  
Vol 74 (3) ◽  
pp. 428-443 ◽  
Author(s):  
Jean-Claude Ruel ◽  
François Ouellet ◽  
Roch Plusquellec ◽  
Chhun-Huor Ung

This paper presents results from a 30 year monitoring of 15 clearcut areas. Study areas were located before cutting in stands having an abundant advance regeneration. Four study areas were initially dominated by black spruce, four by balsam fir, three by jack pine and the last four comprised a mix of species. Stand inventories and regeneration surveys were conducted before harvesting. Harvesting was done in regular logging operations, without any special care to protect the advance growth. Regeneration surveys were taken again after harvesting, 5 years, 10 years, 20 years and 30 years after harvesting. Black spruce stands regenerated to black spruce dominated stands. Balsam fir, which was sometimes abundant in the advance regeneration, did not invade the stands and the abundance of hardwoods was temporary. In some cases a reduction in yield is to be expected. In balsam fir stands, harwoods were more aggressive. A reduction in softwood yield is predicted for three of the four cutovers. The presence of a tall regeneration seems to lead to higher yields in black spruce and balsam fir stands. The evolution of jack pine and mixed stands is quite variable. In some jack pine stands, hardwoods will constitute a significant component of the new stand. In some mixed stands, softwoods are not very abundant whereas in others they form an important part of the stand at 30 years. This study has shown an urgent need for a better understanding of stand dynamics in young stands. Such an understanding is necessary for an adequate forecast of the yield of second growth stands.


1989 ◽  
Vol 65 (5) ◽  
pp. 372-376 ◽  
Author(s):  
Jean-Claude Ruel

A study on the regeneration of leave strips in an alternate strip clearcutting system was conducted in black spruce stands (Picea mariana [Mill.] BSP) in Abitibi in northwestern Quebec. The study consists of 49 leave strips scheduled for harvesting and 24 adjacent first-cut strips. Winter harvesting gave the best results while a prescription aiming at preserving advance growth did not result in any gain. Site moisture regime and harvesting system had no effect on advance growth destruction. Regeneration on first-cut strips was not significantly affected by the cutting of the leave strip.


2001 ◽  
Vol 79 (4) ◽  
pp. 420-428 ◽  
Author(s):  
Jean-François Giroux ◽  
Yves Bergeron ◽  
Jean J Veillette

Giant circular patterns of low tree density in black spruce (Picea mariana) stands were investigated in the Abitibi region of Quebec. We used dendrochronological techniques to test the hypotheses that ring patterns of low tree density are caused either by radial changes in spruce mortality or productivity. Seven circles were sampled. We found no gradient in the age of spruce along circle radii suggesting that rings of low tree density do not expand radially, that is, they are not spatially dynamic entities. The results indicate, however, that spruce trees were less dense and productive within the rings due to excessive moisture in the soil. Measurements of surface elevation, thickness of the organic layer and elevation of the mineral substrate across the circles revealed that a depression in the mineral soil beneath the rings traps the surface water and this area of poor drainage seems to prevent the establishment of black spruce within the rings. The origin of the ring-shaped depressions was attributed to geological or geomorphological causes.Key words: black spruce, Picea mariana, mortality, productivity, rings, geomorphology.


2001 ◽  
Vol 31 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Daniel J Perry ◽  
Jean Bousquet

cDNA-based sequence-tagged-site (STS) markers were used to examine the genetic composition of three mature, layer-origin populations of black spruce (Picea mariana (Mill.) BSP), which were the result of logging operations in the first half of the 20th century, and compare them with four mature, seedling-origin populations that regenerated naturally following fire. The amount of STS-marker variation revealed in these populations was very similar to that previously observed in a rangewide panel of black spruce trees. There was little differentiation among populations, and no significant differences in heterozygosities, numbers of alleles, or fixation indices were evident between layer-origin and fire-origin stands. Likewise, when mating-system parameters were estimated in one population of each of these two types, no significant differences were found; outcrossing was essentially complete with no evidence of mating among relatives. The estimated correlation of paternity within progeny arrays was about 17 and 13% in the fire-origin and layer-origin stands, respectively, but again the observed difference was not statistically significant. At least at the current scale of sampling, silvicultural practices that result in stand replacement by layer-origin advance regeneration appear not to have had negative impact upon the genetic diversity or level of inbreeding in second-growth black spruce stands.


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