scholarly journals Évolution de la régénération après la coupe de peuplements récoltés selon différents procédés d'exploitation

1996 ◽  
Vol 72 (5) ◽  
pp. 519-527 ◽  
Author(s):  
David Pothier
Keyword(s):  
Natural Regeneration ◽  
The Other ◽  
Balsam Fir ◽  
Medium Term ◽  
Mixed Stands ◽  
Advance Regeneration ◽  
Hardwood Species ◽  
Before And After ◽  
Harvesting Systems ◽  
Pine Stands

Between 1982 and 1984, 289 sample plots were established on cutovers distributed across the mixed and the boreal forest zones of Québec. Regeneration surveys before and after clearcutting were used to determine the proportion of regeneration destroyed by four different harvesting systems. Moreover, information on the evolution of the regeneration over the medium term was gathered from surveys realized five and ten years following logging. For all stands combined, harvesting resulted in a reduction of 25 to 40% of the stocking of the regeneration. The lowest decrease in stocking was produced by a feller-forwarder that was more efficient to protect regeneration shorter than 50 cm as compared to harvesting systems using cable skidders. Differences between harvesting systems were no longer apparent after the first five-year-period following logging because establishment of new seedlings was observed in most of the sampled cutovers. The ability of balsam fir to establish under a canopy generally caused an increase of its proportion in the new stands as compared to the original stands. The proportion of hardwood species also tended to increase in comparison to the original stand in such a way that some conifer stands would evolve toward mixed stands if no change in stand composition occurred after the first ten-year period following logging. Natural regeneration of jack pine stands after harvesting seems difficult to obtain since these stands have scarce advance regeneration that is partially destroyed during logging operations. Plantation, fill plantation or seeding could be applied in these stands but harvesting methods providing protection for regeneration should be used in the other stands in order to protect advance regeneration and particularly tall individuals. Key words: clearcutting, advance regeneration, harvesting system, cable skidders, feller-forwarder

Evolution of biodiversity in homogeneous Scots pine stands by an ecologically diversified management

1995 ◽  
Vol 60 ◽  
Author(s):  
N. Lust ◽  
B. Muys
Keyword(s):  
Scots Pine ◽  
Natural Regeneration ◽  
Stand Structure ◽  
Rotation Period ◽  
Pine Forests ◽  
Mixed Stands ◽  
Noticeable Increase ◽  
Hardwood Species ◽  
Pine Stands ◽  
Scots Pine Stands

This  study evaluates three important parameters of biodiversity in first  generation Scots pine forests on sandy soils: herbal layer, natural  regeneration and stand structure. The research was undertaken in the Belgian  Campine Region, where the original oak-birch forest had been destroyed in the  course of time and finally been replaced by monocultures of Scots pine. These  pine forests are characterised by a low biodiversity. In maturing stands of  this type, however, a spontaneous increase of biodiversity is noticed.     Herbal species diversity is very limited in all age classes. Spontaneous  establishment of Scots pine seedlings is presently a widespread phenomenon in  aging stands. Different regeneration patterns are found. Mainly due to the  lengthening of the rotation in combination with the ingrowth of several  hardwood species, the homogeneous Scots pine stands are gradually and  spontaneously transformed into heterogeneous mixed stands, featuring a  noticeable increase of biodiversity.     Nevertheless, selected human interventions may further increase  biodiversity. The fundamental management principles are discussed: avoidance  of big disturbances, lengthening of the rotation period, use of native tree  species, utilization of natural regeneration, protection of small valuable  biotopes and permanent monitoring.

Comparative responses of small mammals, vegetation, and food sources to natural regeneration and conifer release treatments in boreal balsam fir stands of Quebec

1999 ◽  
Vol 29 (7) ◽  
pp. 1128-1140 ◽  
Author(s):  
Nancy Gagné ◽  
Louis Bélanger ◽  
Jean Huot
Keyword(s):  
Small Mammals ◽  
Natural Regeneration ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Rubus Idaeus ◽  
Balsam Fir ◽  
Food Sources ◽  
Ground Vegetation ◽  
Growing Seasons ◽  
Advance Regeneration

Abundance and species diversity of small mammals were compared among three regeneration methods used in boreal balsam fir (Abies balsamea (L.) Mill.) forests. Those methods were natural regeneration after "careful logging" to retain advance regeneration and planting (black spruce, Picea mariana (Mill.) BSP) followed by herbicide (Vision®) release or brushsaw cutting release. Deciduous vegetation was reduced for two growing seasons in both plantation types after treatment, and foliar arthropods decreased for one growing season. In herbicide-treated plantations, red raspberry (Rubus idaeus L.) shrub cover, near-ground vegetation, and production of berries were reduced for two growing seasons. After herbicide release, the abundance of the red-backed vole (Clethrionomys gapperi (Vigors)) was significantly lowered for two growing seasons. This negative effect was associated with reduced cover during the first two post-treatment growing seasons. In the short term, herbicide-treated plantations constitute poorer red-backed vole habitats than brushsaw plantations. In early successional boreal balsam fir stands, planting did not markedly affect small mammals probably because natural regeneration was common in these plantations.

Évolution de la régénération de peuplements résineux et mélangés au cours des 30 années après coupe à blanc mécanisée

1998 ◽  
Vol 74 (3) ◽  
pp. 428-443 ◽  
Author(s):  
Jean-Claude Ruel ◽  
François Ouellet ◽  
Roch Plusquellec ◽  
Chhun-Huor Ung
Keyword(s):  
Black Spruce ◽  
Jack Pine ◽  
Balsam Fir ◽  
Stand Dynamics ◽  
Mixed Stands ◽  
Significant Component ◽  
Advance Regeneration ◽  
Second Growth ◽  
Spruce Stands ◽  
Coupe À Blanc

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.

Dynamique de la sapinière à bouleau jaune de l'est après une épidémie de tordeuse des bourgeons de l'épinette

1999 ◽  
Vol 75 (3) ◽  
pp. 515-534 ◽  
Author(s):  
Pierre Pominville ◽  
Stéphane Déry ◽  
Louis Bélanger
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
The Other ◽  
Balsam Fir ◽  
Betula Alleghaniensis ◽  
White Birch ◽  
Yellow Birch ◽  
Mixed Stands ◽  
The Dead

An outbreak of spruce budworm, Choristoneura fumiferana (Clem.), occurred between 1974 and 1987, in Quebec, in the eastern balsam fir, Abies balsamea (L.) Mill, - yellow birch, Betula alleghaniensis Britton, ecoclimatic sub-domain. The effect of this disruption has been assessed in mesic balsam fir stands killed during the outbreak, in mesic balsam fir stands partially damaged and in the following stands, also partially damaged: mesic yellow birch – balsam fir stands, mesic white birch, Betulapapyrifera Marsh., - balsam fir stands, mesic balsam fir – yellow birch stands, mesic balsam fir – white birch stands and xeric balsam fir stands. To that effect, surveys were led before, immediately after, and about five years after the outbreak in two blocks that have not been protected with insecticides. These blocks, located in Charlevoix and in Shipshaw management units, are second growth stands originating from clearcuts which occured about 50 years ago. Approximately five years after the outbreak, abundant coniferous regeneration was found everywhere except in the mesic yellow birch –balsam fir stand and in the dead mesic balsam fir stand, where softwood represented less than 50% of the regeneration. On the other hand, young softwood stems were located under the regeneration of white birch and of mountain maple, Acer spicatum Lam, in dead balsam fir stands, in balsam fir – white birch stands, as well as in living balsam fir stands and under mountain maple in yellow birch – balsam fir stands and in balsam fir – yellow birch stands. Our age structures indicate that softwood advance growth was relatively rare in these stands. Thus, during the opening of the canopy by the spruce budworm, intolerant hard-woods and shrubs invaded the still available microsites. In the dead balsam fir stands, stocking of the dominant hardwood regeneration stems is equivalent to that of softwood. Thus, dead balsam fir stands are turning to mixed stands. Xeric stands will remain softwood stands since they show luxuriant softwood regeneration dominating in height. In the other stands, we will have to wait the harvest period before we can adequately assess succession.

The Effects of Full-Tree and Tree-Length Harvests on Natural Regeneration

1994 ◽  
Vol 11 (4) ◽  
pp. 131-137 ◽  
Author(s):  
Bryce G. McInnis ◽  
Mark R. Roberts
Keyword(s):  
Solar Radiation ◽  
Natural Regeneration ◽  
Mechanical Damage ◽  
Mixed Stands ◽  
Advance Regeneration ◽  
Tree Length

Abstract Changes in density and stocking of natural regeneration were analyzed for paired full-tree (delimbed off-site) and tree-length (delimbed on-site) clearcuts applied side by side in three mixed stands. No special effort was made to preserve advance regeneration. Three-stand means indicated larger advance softwood regeneration losses on the tree-length sites during harvests, suggesting greater direct mechanical damage, but larger softwood losses occurred on the full-tree sites during the first summer after harvests, suggesting a more stressful postharvest environment. After 1 yr, losses of advance spruce and fir did not differ significantly between treatments within stands. Recruitment of intolerant and intermediate hardwoods was greater after the full-tree harvests, probably because of higher levels of solar radiation. Results indicate (a) significantly greater densities of intolerant and intermediate hardwoods after full-tree harvests of mixed stands, and (b) that with care taken to preserve advance growth during harvests, advance softwood survival is better when slash is left on cutovers. North. J. Appl. For. 11(4): 131-137.

Ecological factors affecting the abondance of advance regeneration in Quebec's southwestern boreal forest

1996 ◽  
Vol 26 (5) ◽  
pp. 888-898 ◽  
Author(s):  
Daniel D. Kneeshaw ◽  
Yves Bergeron
Keyword(s):  
Boreal Forest ◽  
Natural Regeneration ◽  
Ecological Factors ◽  
Stand Age ◽  
Site Classification ◽  
Past Century ◽  
Mixed Stands ◽  
Large Variability ◽  
Advance Regeneration ◽  
Successional Species

Boreal forest disturbance regimes have changed during the past century, in turn changing regeneration and stand dynamics of these forests. This is occurring at the same time that the forest industry is emphasizing operations that take advantage of pre-established natural regeneration. This study has therefore investigated the effect of various ecological factors on the abundance of Abiesbalsamea (L.) Mill., Piceaglauca (Moench) Voss, Piceamariana (Mill.) BSP, Thujaoccidentalis L., Betulapapyrifera Marsh., and Populustremuloides Michx. natural regeneration in some boreal stands in the Abitibi region of Quebec. Abiotic ecological site classification variables were found to be poorly correlated with seedling densities for most species. Parent trees, as a seed source, and stand type, for its influence on the quality of the seedbed, were strongly correlated with abundant conifer regeneration. As expected, time since fire was positively correlated with seedling abundance for late successional species, whereas it was not related to the abundance of early successional species. Post-fire disturbances, such as those due to spruce budworm (Choristoneurafumiferana (Clem.)) outbreaks, accounted for the variations in seedling densities observed with respect to stand age. The presence of budworm-caused gaps was positively correlated with regeneration abundance, whereas shrub competition, which was greatest in large gaps, was negatively correlated with advance regeneration density. Forest management based on abundance of pre-established regeneration should focus mainly on mixed stands because seedling density is very low in hardwood stands and because of the strong competition found in large gaps of resinous forests. The low number of seedlings observed, especially in coniferous stands, may limit the effectiveness of operations that take advantage of advance regeneration. The large variability observed among site and stand types limits their operational use in predicting seedling densities.

Ecological factors affecting abundance of advanced growth in jack pine (Pinus banksiana Lamb.) stands of the boreal forest of northwestern Quebec

1993 ◽  
Vol 69 (5) ◽  
pp. 561-568 ◽  
Author(s):  
Martin Béland ◽  
Yves Bergeron
Keyword(s):  
Pinus Banksiana ◽  
Abies Balsamea ◽  
White Spruce ◽  
Jack Pine ◽  
Balsam Fir ◽  
Moisture Regime ◽  
Mixed Stands ◽  
Pine Regeneration ◽  
Significant Difference ◽  
Pine Stands

Natural regeneration in jack pine (Pinus banksiana Lamb.) stands in Quebec is only sufficient 4% of the time and up to only 33% of the time in mixed stands. This study evaluates the usefulness of forest ecological types as defined by the Quebec Ministry of Forests in predicting abundance of advanced growth in pure and mixed jack pine stands of the Abitibi region, in north-western Quebec. Trees above 1.3 m in height and up to 5 cm DBH were tallied in 102 quadrats of 20 × 20 metres to evaluate advanced growth densities. No significant difference in advanced growth densities was observed between the two main types of surficial geological deposit in the region, lacustrine clays and glacial tills. Only shallow till and organic deposits over bedrock and fluvio-glacial sands showed significantly higher advanced growth densities. Prediction can be improved by using ecological variables such as soil texture, moisture regime, distance from a seed source and stand composition. Abundance of black spruce (Picea mariana (Mill.) B.S.P.) regeneration is positively associated with the proportion of sand in the soil profile and with drier sites; advanced growth of balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss.) is weakly associated with the distance to a fire-preserved zone containing seed trees. Abundance of pin cherry (Prunus pensylvanica L.f.), probably associated with canopy openings, is positively linked with abundance of balsam fir and white spruce advanced growth. Jack pine regeneration by means of advanced growth occurs almost exclusively in jack pine stands on sand; higher proportions of hardwoods in the overstory appear to be negatively linked to jack pine advanced growth. Although the site variables studied showed some significant relationships with advanced growth abundance (maximum R2 = 0.32) which were slightly improved with stand composition variables (maximum R2 = 0.38), no satisfactory predictive model could be implemented. Key words: jack pine, advanced growth, ecological classification

Arthroscopy in Arthrosis: Is It Worth it? A case Presentation

2018 ◽  
Vol 69 (8) ◽  
pp. 2232-2235
Author(s):  
Marius Moga ◽  
Mark Edward Pogarasteanu ◽  
Antoine Edu
Keyword(s):  
Clinical Status ◽  
Loose Body ◽  
Point Of View ◽  
The Other ◽  
Joint Range Of Motion ◽  
Objective Evidence ◽  
Before And After ◽  
Total Knee ◽  
Joint Range

The role of arthroscopy in incipient and mild arthrosis, even combined with proximal tibial ostetomy, is well known and well documented. On the other hand, its role in the treatment of advanced arthrosis of the large joints, especially the knee, is a subject of controversy. The proponents of the use of arthroscopy in advanced arthrosis claim that meniscectomy, synovectomy, ostophytectomy, chondral lesion stabilization, arthroscopic release, plica and loose body removal greatly improve the quality of life for most patients, especially if followed by the use of viscoelastic injection, by diminishing pain and improving joint range of motion. The opponents claim that, even though the advantages are clear in the cases that refuse arthroplasty, in all the other cases the surgical indication should be total knee arthroplasty, as the clinical relief is temporary, but with all the risks of a surgical intervention. We have conducted an overview of the recent literature, in order to find objective evidence to sustain either point of view. We focused on articles published that included an objective measurement of before and after clinical status through clinical scores and objective measurements. We also focused on the follow-up period and on the evolution of the pathology after arthroscopy.

Antimicrobial Effect of 940 nm Diode Laser based on Photolysis of Hydrogen Peroxide in the Treatment of Periodontal Disease

2018 ◽  
Vol 69 (8) ◽  
pp. 2081-2088 ◽  
Author(s):  
Alin Alexandru Odor ◽  
Edwin Sever Bechir ◽  
Deborah Violant ◽  
Victoria Badea
Keyword(s):  
Hydrogen Peroxide ◽  
Laser Therapy ◽  
Diode Laser ◽  
Antimicrobial Effect ◽  
The Other ◽  
Control Group ◽  
Group 4 ◽  
Periodontal Bacteria ◽  
Severe Periodontitis ◽  
Before And After

Moderate and severe periodontitis represents a challenge in the non-surgical periodontal therapy. Due to the lack of evidence regarding the antimicrobial effectiveness of 940 nm diode laser in periodontal treatment, this study aimed to evaluate the antimicrobial effect of hydrogen peroxide (H2O2) photolysis performed with 940 nm diode laser in the treatment of moderate and severe periodontitis. Twenty-five patients with 100 teeth were selected for this pilot study. The test teeth were randomly assigned to one of the four treatment groups: Group 1: scaling and root planning (SRP) (control group); and the following experimental groups: Group 2: H2O2; Group 3: 940 nm diode laser therapy; Group 4: 940 nm diode laser therapy and H2O2. Clinical examinations, like probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were performed before and after the treatment. The microbiological evaluation, effectuated before and after the treatment, included nine periodontal bacteria species and investigated by means of real-time PCR assay. The clinical and bacterial differences in the tested groups, was assessed between control group and the other three experimental groups, as well as between the experimental groups. The total bacteria load was reduced for all four studied groups. Group 4 (diode laser + H2O2) showed significant bacterial reduction of the major periodontal bacteria like Pg., Tf., Td., Pi., Pm., Fn (p[0.001) than the other 3 groups (p]0.001). Also the periodontal clinical parameters, like PD, CAL and BOP showed a significant reduction after the photolysis of H2O2 with the 940 nm diode laser (p[0.001). Differences between tested groups showed a significant beneficial results in regard to Group 4.It is suggested that the photoactivation of H2O2 with the 940 nm diode laser can be used successfully in adjunctive to the non-surgical periodontal treatment as a bactericidal tool.

Growth and management of mixed Pinus sylvestris - Quercus robur stands in Flanders, Belgium

1993 ◽  
Vol 58 ◽  
Author(s):  
D. Maddelein ◽  
J. Neirynck ◽  
G. Sioen
Keyword(s):  
Pinus Sylvestris ◽  
Natural Regeneration ◽  
Quercus Robur ◽  
Good Growth ◽  
Pedunculate Oak ◽  
Selection System ◽  
Management Options ◽  
Stand Management ◽  
Pine Stands

Mature  Scots pine (Pinus sylvestris  L.) stands are dominating large parts of the Flemish forest area. Broadleaved  species regenerate spontaneously under this pine canopy. This study studied  the growth and development of two planted pine stands with an older natural  regeneration, dominated by pedunculate oak (Quercus  robur L.), and discussed management options for  similar stands.     The results indicated a rather good growth of the stands, with current  annual increments of 5 m3.ha-1.yr-1. The pine overstorey is growing into valuable sawwood  dimensions, while the broadleaved understorey slowly grows into the  upperstorey. The quality of the regeneration is moderate but can be improved  by silvicultural measurements (pruning, early selection).     In both stands, an interesting (timber production, nature conservation)  admixture of secondary tree species is present in the regeneration. Stand  management is evolving from the classical clearcut system towards a  combination of a type of selection and group selection system.

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