Dynamique forestière après coupe partielle dans la Forêt expérimentale du Lac Édouard, Parc de la Mauricie, Québec

2003 ◽  
Vol 79 (3) ◽  
pp. 672-684 ◽  
Author(s):  
Louis Archambault ◽  
Jean Bégin ◽  
Claude Delisle ◽  
Mathieu Fortin

Forest dynamics following a partial cut conducted in the early 1950s in the Lac Édouard Experimental Forest in the Mauricie National Park, Quebec, Canada, were studied. Changes in vegetation were analyzed for the period between 1946 and 2001 in 109 mesic stands of the sugar maple – yellow birch bioclimatic domain. Three cutting intensities were considered: 1) low intensity, 15–30% of the basal area; 2) moderate intensity, 30–45% of the basal area; and 3) uncut. More than fifty years following cutting, the original relative proportion of the deciduous and softwood species was maintained. The relative proportion of basal area occupied by softwood species relative to the total basal area varied only from 2.0% to 7.4%. Red spruce (Picea rubens Sarg.) basal area increased in forest types Cornus (Co) and Oxalis-Cornus (O-Co) whereas balsam fir basal area decreased. In the Viburnum-Oxalis (Vi-O) forest type, sugar maple (Acer saccharum Marsh.) basal area increased and yellow birch (Betula alleghaniensis Britt.) decreased. Cutting areas were not invaded by competition species such as mountain maple (Acer spicatum Lamb.). In the Co and O-Co forest types, the regeneration density is probably sufficient to maintain the current cover type. In the Vi-O forest type, where moderate partial cutting was conducted, the deciduous component could substantially increase. Stands reacted positively to partial cutting. The increased growth of residual stems and the arrival of new stems resulted in 2001 total basal areas that were equal to or larger than those observed before cutting (1946). Key words: forest dynamics, partial cutting, yellow birch, red spruce, balsam fir

2003 ◽  
Vol 79 (3) ◽  
pp. 462-474 ◽  
Author(s):  
J. Loo ◽  
N. Ives

The Acadian Forest Region comprises the three Maritime Provinces of Canada, each of which has a distinct history resulting in different patterns of land ownership, land use, and impacts on the forest. The region encompasses a high degree of physiographic and biological diversity, being situated where the warm, moist influence of the Gulf Stream from the south collides with the cold Labrador Current and the boreal forest gradually gives way to mostly deciduous forest. Natural forest types in the Acadian Forest Region include rich tolerant hardwood, similar to the deciduous forests to the south; spruce-fir forest, similar to boreal forest to the north; and an array of coniferous, deciduous, and mixed intermediate types. Red spruce (Picea rubens Sarg.), yellow birch (Betula alleghaniensis Britt.), sugar maple (Acer saccharum Marsh.) and balsam fir (Abies balsamea (L.) Mill.) are considered characteristic of the Acadian Forest Region. Except for one quantitative study in one county of New Brunswick, and another study on Prince Edward Island, most knowledge of the historical forest condition has been gleaned from early descriptions by explorers, surveyors, and settlers of the Maritimes region. Although some regions have been affected much more than others, little, if any forested area has escaped human influence over the past four centuries. A general result of human activities has been a shift in successional status and age distribution, with increased frequency of relatively young, often even-aged, early successional forest types including balsam fir, white spruce (Picea glauca (Moench) Voss), red maple (Acer rubrum L.), white birch (Betula papyrifera Marsh.), and trembling aspen (Populus tremuloides Michx.). Both the abundance and age of late-successional species such as sugar maple, red spruce, eastern hemlock (Tsuga canadensis L. Carrière), yellow birch, cedar (Thuja occidentalis L.), and beech (Fagus grandifolia Ehrh.) have declined. Key words: pre-European forest, Maritime Provinces, historical ecology, witness trees, Acadian forest types, natural disturbance


Author(s):  
Alex Noel ◽  
Jules Comeau ◽  
Salah-Eddine El Adlouni ◽  
Gaetan Pelletier ◽  
Marie-Andrée Giroux

The recruitment of saplings in forest stands into merchantable stems is a very complex process, thus making it challenging to understand and predict. The recruitment dynamics in the Acadian Forest Region of New Brunswick are not well known or documented. Our objective was to draw an inference from existing large scale routine forest inventories as to the different dynamics behind the recruitment from the sapling layer into the commercial tree size layer in terms of density and occurrence of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britt.) following harvesting, by looking at many factors on a wide range of spatial and temporal scales using models. Results suggest that the variation in density and probability of occurrence is best explained by the intensity of silvicultural treatment, by the merchantable stem density in each plot, and by the proportion of merchantable basal area of each group of species. The number of recruits of sugar maple and yellow birch stems tend be higher when time since last treatment increases, when mid to low levels of silvicultural treatment intensity were implemented, and within plots having intermediate levels of merchantable stem density. Lastly, our modeling efforts suggest that the probability of occurrence and density of recruitment of both species tend to increase while its share of merchantable basal area increases.


2013 ◽  
Vol 89 (04) ◽  
pp. 512-524 ◽  
Author(s):  
Martin Béland ◽  
Bruno Chicoine

We examined applicability of various partial cutting systems in order to regenerate tolerant hardwood stands dominated by sugar maple (Acer saccarhum), American beech (Fagus grandifolia) and yellow birch (Betula alleghaniensis) on northern New Brunswick J.D. Irving Ltd. freehold land. Sampling of 1065 one-m2 plots in 31 stands managed by selection cutting, shelterwood method and strip or patch cutting and in six control stands allowed a 15-year retrospective study of natural regeneration in stands of low residual densities and with minimal soil disturbance and no control of competing vegetation. Beech regeneration was most abundant in the patch cuts, yellow birch in shelterwood stands and sugar maple in the selection system areas. Results suggest that initial stand conditions influence the composition of the regeneration more than the prescribed treatment. At the stand scale (a few hectares), sugar maple recruitment was positively influenced by its proportion in the initial stand, and negatively by the cover of herbs and shrubs. Yellow birch regeneration was mainly affected by shrub competition. At the plot (1 m2) scale, mineral soil and decayed wood substrates and ground-level transmitted light were determinant factors for yellow birch regeneration. Beech-dominated stands were likely to regenerate to beech. A dense beech sucker understory was promoted in harvested patches. Areas with dense understory of American beech, shrubs, or herbs require site preparation to reduce interference either before or at the time of partial cutting. Shelterwood seed cutting and selection cutting should leave a residual of 12 m2/ha and 17 m2/ha respectively in seed trees uniformly distributed.


2003 ◽  
Vol 33 (5) ◽  
pp. 862-869 ◽  
Author(s):  
Jose Alexander Elvir ◽  
G Bruce Wiersma ◽  
Alan S White ◽  
Ivan J Fernandez

Responses in basal area increment (BAI) of sugar maple (Acer saccharum Marsh.) and red spruce (Picea rubens Sarg.) to chronic ammonium sulfate ((NH4)2SO4) treatment were examined at the Bear Brook Watershed in Maine. The Bear Brook Watershed is a pair-watershed forest ecosystem study with West Bear watershed treated with (NH4)2SO4 at a rate of 1800 equiv.·ha–1·year–1 since 1989, while East Bear watershed serves as a reference. Following 10 years of treatment, BAI was significantly higher for sugar maple trees growing in the treated watershed, with yearly increases relative to the reference watershed ranging from 13% in 1999 to 104% in 1996. The increase in sugar maple radial growth was attributed to a fertilization effect from the (NH4)2SO4 treatment. A reduction in BAI in sugar maple growing in the treated watershed observed in 1998 and 1999 was attributed to internal stresses and growth allocation to crown recovery after the severe 1998 ice storm. Red spruce showed no BAI growth responses to the treatment. Lower foliar Mg and Ca concentrations in red spruce in the treated watershed and lower soil responses to N enrichment in treated softwood stands compared with treated hardwood stands could explain the lack of BAI response in red spruce.


1997 ◽  
Vol 54 (1) ◽  
pp. 1-38 ◽  
Author(s):  
M. T. Nascimento ◽  
J Proctor ◽  
D. M. Villela

Maracá is a riverine island located in the Rio Uraricoera in Roraima State (Brazil) and has an area of about 100,000ha. A forest type dominated by Peltogyne gracilipes Ducke (Caesalpiniaceae) occurs on Maracá Island on a range of soil types. This study compares the structure, floristic composition and soils of the Peltogyne forest with the most widespread lowland forest type on Maracá. Three 0.25ha plots were set up in each of three forest types: Peltogyne-rich forest (PRF), Peltogyne-pooi forest (PPF) and forest without Peltogyne (FWP). Within each plot all trees (≤ 10cm dbh) were recorded. Seedlings and saplings were sampled in subplots of 2m × 1m (seedlings) and 4m × 4m (saplings). In the PPF and FWP, Sapotaceae were the most important family with the highest relative dominance and relative density values. Caesalpiniaceae showed high values in the PRF and PPF. Licania kunthiana, Pradosia surinamensis and Simarouba amara occurred in the canopy layer in all the forest types. Peltogyne dominated the canopy in the PRF and comprised 20% of stems and 53% of the total basal area of all trees ≥ 10cm dbh, and 91% of the stems and 97% of the total basal area of individuals ≥ 50cm dbh. In PPF, Lecythis corrugata and Tetragastris panamensis were the most abundant species, followed by Peltogyne. In the FWP the most abundant trees (≥ 10cm dbh) were Licania kunthiana and Pradosia surinamensis. In all forest types, the soils were sandy and acid with low concentrations of extractable phosphorus and exchangeable cations, but the soils under PRF were notably richer in magnesium.


2013 ◽  
Vol 43 (3) ◽  
pp. 224-233 ◽  
Author(s):  
Marcel Prévost ◽  
Daniel Dumais

Estimating residual tree survival and growth is crucial for evaluating the overall merit of partial harvesting. In this case study, we present the effects of different cutting intensities (0%, 40%, 50%, and 60% of merchantable (diameter at breast height ≥ 9.1 cm) basal area (BA)) on the response of residual trees in two mixed yellow birch (Betula alleghaniensis Britt.) – conifer stands in eastern Quebec, Canada. Primarily aimed at promoting regeneration establishment, the experiment was conducted in two sites 90 km apart (Armagh and Duchesnay), each one containing four replicates of treatments in a randomized block design. Mortality after cutting decreased with increasing BA removal, but losses were two to three times higher at Armagh (62–138 stems/ha) than at Duchesnay (22–88 stems/ha). Loss of conifer stems involved primarily balsam fir (Abies balsamea (L.) Mill.) under natural conditions (control), whereas fir and red spruce (Picea rubens Sarg.) were equally affected in partial cuts. Red maple (Acer rubrum L.) and paper birch (Betula papyrifera Marsh.) were lost regardless of treatment. As a whole, growth in merchantable BA increased with cutting intensity. Uniform partial cuts produced good BA growth response from conifers at Armagh (0.27–0.28 m2·ha−1·year−1) and from hardwoods at Duchesnay (0.16–0.25 m2·ha−1·year−1), whereas BA growth was negligible for both species groups in the control. We examine the role of species composition and stand structure before cutting in the response of residual trees.


Author(s):  
A. R. Mendes Pontes ◽  
V. M. Guedes Layme ◽  
L. R. Rodrigues de Lucena ◽  
D. J. Chivers

Assemblages of medium and large–sized mammals were studied in the Guyana shield of the Brazilian Amazonia. Diurnal and nocturnal line–transect samplings were carried out via the line–transect method in five different forest types along a 10–km transect, along which we also recorded habitat variables, such as tree species diversity, reproductive phenology, and residual fruit productivity. Group density was separately calculated for all mammalian species in the five forest types. Stepwise multiple regression analyses were performed to determine which habitat variables best predicted the mammalian species densities in the sampled forests. The sole determinants of mammalian densities in the forest types studied were basal area of each forest type, total number of tree species in each forest type, and tree reproductive phenology.


Author(s):  
Joseph Hitimana ◽  
James Legilisho Ole Kiyiapi ◽  
Balozi Kirongo Bekuta

Forest measurements, especially in natural forests are cumbersome and complex. 100% enumeration is costly and inefficient. This study sought to find out reliable, efficient and cost-effective sampling schemes for use in tropical rain forest (TRF), moist montane forest (MMF) and dry woodland forest (DWF) in Kenya. Forty-eight sampling schemes (each combining sampling intensity (5, 10, 20, 30%), plot size (25, 50, 100, 400 m2) and sampling technique (simple random sampling, systematic sampling along North-South and along East-West orientations) were generated for testing estimates of forest attributes such as regeneration through simulation using R-software. Sampling error and effort were used to measure efficiency of each sampling scheme in relation to actual values. Though forest sites differed in biophysical characteristics, cost of sampling increased with decreasing plot size regardless of the forest type and attribute. Accuracy of inventory increased with decreasing plot size. Plot sizes that captured inherent variability were 5mx5m for regeneration and trees ha-1 across forest types but varied between forest types for basal area. Different sampling schemes were ranked for relative efficiency through simulation techniques, using regeneration as an example. In many instances systematic sampling-based sampling schemes were most effective. Sub-sampling in one-hectare forest unit gave reliable results in TRF (e.g. SSV-5mx5m-30%) and DWF (e.g. SSV-10mx10m-30%) but not in MMF (5mx5m-100%). One-hectare-complete-inventory method was found inevitable for regeneration assessment in montane forest.


2008 ◽  
Vol 38 (2) ◽  
pp. 317-330 ◽  
Author(s):  
Marcel Prévost

This paper presents the 5 year results of different cutting intensities (removal of 0%, 40%, 50%, 60%, and 100% of the basal area) applied in two mixed yellow birch ( Betula alleghaniensis Britt.) – conifer stands of eastern Quebec, Canada. Two sites 90 km apart were used: Armagh and Duchesnay. Each site had four replicates of the treatments in a randomized block design. The effect on light availability was similar in the two sites: the 0%, 40%, 50%, 60%, and 100% cuts transmitting a mean of 5%, 21%, 26%, 30%, and 94% of full light, respectively, during the first summer. Soil temperature increased only in the 100% cut (4−5 °C, maximum daily temperature). Soil disturbance during harvest was higher at Duchesnay than at Armagh, which clearly improved seedbed receptivity, particularly to yellow birch. After 5 years, treated areas contained 21 000 to 48 300 seedlings/ha at Duchesnay compared with 5500 – 10 500 seedlings/ha at Armagh. Significant losses of coniferous advance growth were observed at both sites, but a subsequent seedling recruitment occurred only at Duchesnay. Red spruce ( Picea rubens Sarg.) showed superior establishment in the 60% cut (4400 seedlings/ha) than under other cutting intensities (1600–2100 seedlings/ha), whereas balsam fir ( Abies balsamea (L.) Mill.) responded well to all partial cutting treatments. At both sites, pin cherry ( Prunus pensylvanica L.f.) was the main competing species in the 100% cut, whereas densities of the preestablished mountain maple ( Acer spicatum Lamb.) and striped maple ( Acer pensylvanicum L.) either remained the same or increased in the partial cuts.


1997 ◽  
Vol 14 (4) ◽  
pp. 178-182 ◽  
Author(s):  
Gregory G. McGee ◽  
John P. Birmingham

Abstract While several authors have noted tree regeneration on decaying logs, the role that "nurse logs" play in maintaining tree diversity in eastern North American forests has remained unquantified. We sampled small seedling (≤ 5 cm high) densities of seven tree species on and directly adjacent to logs in two northern hardwood stands in the Adirondack mountains of New York. Polar ordination of 42 microsite plots revealed distinctly different small seedling communities on logs vs. forest floor. Yellow birch and red spruce densities were 24 times and 5 times greater on logs than forest floor, while those of sugar maple and striped maple were 8 times and 4 times greater on the forest floor. Maintaining a natural level (~5% ground cover) of well distributed logs can supplement site preparation techniques such as soil scarification to provide regeneration sites for yellow birch and red spruce, particularly in heavily stocked northern hardwood stands. North. J. Appl. For. 14(4):178-182.


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