scholarly journals Histoire Postglaciaire de la Végétation dans la Région de Mont-Saint-Pierre, Gaspésie, Québec

2007 ◽  
Vol 38 (3) ◽  
pp. 257-274 ◽  
Author(s):  
Claude Labelle ◽  
Pierre J. H. Richard
Keyword(s):  
Acer Saccharum ◽  
Abies Balsamea ◽  
Pinus Strobus ◽  
Larix Laricina ◽  
Betula Alleghaniensis ◽  
Betula Papyrifera ◽  
Fraxinus Nigra

RÉSUMÉLes analyses pollinique et macrofossile de sédiments de deux lacs des environs de Mont-Saint-Pierre (Gaspésie), l'un dans la vallée côtière, l'autre sur le plateau, permettent de reconstituer l'histoire postglaciaire de la végétation dans deux situations physiographiques contrastées. Seul le plateau a été colonisé par une végétation initiale de type toundra (> 10 400 ans BP), pendant que la vallée était encore en partie ennoyée par la mer de Goldthwait. L'afforestation du plateau fut caractérisée d'abord par des populations de Picea sp., accompagné de Populus sp. et Larix laricina, puis par un envahissement progressif par Abies balsamea et Betula papyrifera. La baisse de la représentation pollinique de l'aulne vert (Alnus cf. crispa), maximale durant l'afforestation, paraît être un indicateur assez fidèle de la fermeture de la couverture forestière. Cette phase se termine vers 9000 ans BP sur le plateau. Le rythme de l'afforestation a été différent dans la vallée. Des taxons héliophiles s'y sont maintenus plus longtemps, ce qui peut être relié à l'activité des versants abrupts qui flanquent la vallée. Malgré des variations de l'abondance relative des arbres, la sapinière à bouleau blanc a sans doute occupé le plateau depuis 9000 ans BP environ. Par contre, la végétation de la vallée s'est passablement modifiée jusque vers 5000 à 4500 ans BP, par la migration successive de Betula alleghaniensis, de Pinus strobus, de Fraxinus nigra, dAcer saccharum et d'Ulmus americana. L'implantation progressive de ces arbres relativement thermophiles est à l'origine de la diversité du paysage actuel de la vallée. Ces reconstitutions permettent d'écarter l'hypothèse de Dansereau (1944) selon laquelle les érablières à Acer saccharum de la Gaspésie seraient des groupements hérités de l'optimum climatique de l'Holocène moyen, au cours duquel les érablières auraient été largement répandues sur le territoire. Les données montrent que ces érablières datent de l'Holocène Supérieur, la migration d'Acer saccharum ayant sans doute été freinée par des barrières topo-climatiques entraînant une discontinuité prononcée des habitats pouvant accueillir cette espèce.

scholarly journals Végétation tardiglaciaire et postglaciaire au sud-est du parc des Laurentides, Québec

2011 ◽  
Vol 35 (3) ◽  
pp. 345-359 ◽  
Author(s):  
Claude Labelle ◽  
Pierre J.H. Richard
Keyword(s):  
Picea Mariana ◽  
Picea Glauca ◽  
Abies Balsamea ◽  
Pinus Strobus ◽  
Larix Laricina ◽  
Betula Papyrifera ◽  
Betula Glandulosa

L’analyse pollinique des sédiments de trois lacs situés au sud-est du parc des Laurentides a permis de retracer les étapes de la recolonisation végétale post-wisconsinienne. Celle-ci s’est effectuée selon un schéma assez constant à travers le secteur à l’étude. Au début, la végétation était très ouverte, mais tout de même relativement riche en taxons herbacés et arbustifs. Cette phase initiale de végétation (sous-zone la) fut suivie, après une période de transition (sous-zone 1b), par une végétation luxuriante de type toundra (sous-zone 1c). Celle-ci fut à son tour remplacée par une végétation de type toundra arbustive (sous-zone 1d) où l’on voit s’accroître l’importance de Betula glandulosa et d’autres éléments arbustifs. Avec un certain métachronisme entre les sites, l’afforestation s’est amorcée par l’installation du Populus cf. tremuloïdes (sous-zone 2a) et s’est poursuivie par l’arrivée de Picea mariana (fin de la sous-zone 2a) puis, par celle d’une série d’arbres tels Betula papyrifera, Pinus cf. divaricata, Abies balsamea, Picea glauca et Larix laricina (sous-zone 2b). Pendant cette dernière phase de l’afforestation, l’abondance du pollen d’Alnus cf. crispa dans les spectres est maximale. Il semble qu’au moins mille ans se soient écoulés avant l’arrivée des arbres autres que le Populus cf. tremuloïdes. Par la suite, l’histoire de la végétation forestière (zone 3) a été plutôt monotone. Bien que les diagrammes révèlent des périodes de plus grande abondance de certains taxons (Pinus strobus, Picea mariana, Pinus et. divaricata), la majorité des arbres, présents actuellement dans la région, ont migré très tôt à l’Holocène.

Gradient analysis of Larix laricina dominated wetlands in Canada's southeastern boreal forest

2001 ◽  
Vol 79 (4) ◽  
pp. 444-456 ◽  
Author(s):  
Martin-Philippe Girardin ◽  
Jacques Tardif ◽  
Yves Bergeron
Keyword(s):  
Boreal Forest ◽  
Abies Balsamea ◽  
Hierarchical Classification ◽  
Canopy Cover ◽  
Larix Laricina ◽  
Betula Papyrifera ◽  
Kalmia Angustifolia ◽  
Fraxinus Nigra ◽  
Hierarchical Classification Analysis ◽  
Substrate Ph

With the objective of understanding how vegetation was structured in four Larix laricina (Du Roi) K. Koch dominated wetlands in north-western Quebec, 186 point-centred quarters were sampled in four stands. For each point, both biotic and abiotic variables were collected and species cover was recorded. Divisive hierarchical classification analysis (Twinspan) identified nine vegetation clusters: i) Larix laricina & Spiraea alba, ii) Larix laricina & Kalmia angustifolia, iii) Larix laricina, Picea mariana & Alnus rugosa, iv) Larix laricina & Betula pumila, v) Thuja occidentalis & Trientalis borealis, vi) Abies balsamea & Betula papyrifera, vii) Fraxinus nigra & Onoclea sensibilis, viii) Alnus rugosa, and ix) Eleocharis smallii. Results of the canonical correspondence analyses indicated that the distribution of these clusters was mainly related to (i) distance from shore, (ii) shade (canopy cover), (iii) substrate nitrate concentration (in relation to the abundance of Kalmia angustifolia and Alnus rugosa), (iv) substrate pH (in relation to the abundance of Sphagnum spp.), and (v) substrate conductivity. Several characteristics of the water table also affected species distribution, including pH, depth, and carbon concentration. Further studies should address the effect of the presence of Kalmia angustifolia and Alnus rugosa on larch growth.Key words: larch, wetland, vegetation analysis, flooding, boreal forest.

scholarly journals Long-term compositional changes following partial disturbance revealed by the resurvey of logging concession limits in the northern temperate forest of eastern Canada

2016 ◽  
Vol 46 (7) ◽  
pp. 943-949 ◽  
Author(s):  
Victor Danneyrolles ◽  
Dominique Arseneault ◽  
Yves Bergeron
Keyword(s):  
Acer Saccharum ◽  
Temperate Forest ◽  
Land Use Changes ◽  
Abies Balsamea ◽  
Forest Composition ◽  
Betula Alleghaniensis ◽  
Eastern Canada ◽  
Partial Cutting ◽  
Compositional Changes

Land use changes that are linked to European settlement of North America have transformed northeastern temperate forest landscapes. Many studies report a regional increase of young early-successional forests due to high disturbance rates since the preindustrial era (fire, land clearing, and clear-cuts). In this study, we document specific compositional changes to present-day mature forest landscapes, which have only been managed with partial cutting (high-grading and diameter-limit cuts) since the preindustrial era in southwestern Quebec. We resurveyed 108 forest observations that were extracted from logbooks of former logging concession limits (surveyed between 1870 and 1890). Results highlight an increase in mid- to late-successional shade-tolerant taxa (Betula alleghaniensis Britton, Thuja occidentalis L., Acer saccharum Marsh.) at the expense of preindustrial dominant conifers (Abies balsamea (L.) Mill., Pinus strobus L.). Former logging activities and spruce budworm (Choristoneura fumiferana Clemens) outbreaks appear to be the main drivers of these changes, which were also strongly structured across the topographic gradient. To some extent, these results highlight the relevance of partial cutting management, as it has allowed long-term maintenance of a mid- to late-successional forest composition, while also pointing the need for P. strobus restoration. We conclude that by allowing site-specific comparisons, the resurvey of historical observations greatly improve the analytical strengths of historical reconstruction.

Tree seedling growth and mortality responses to manipulations of calcium and aluminum in a northern hardwood forest

2002 ◽  
Vol 32 (6) ◽  
pp. 954-966 ◽  
Author(s):  
Richard K Kobe ◽  
Gene E Likens ◽  
Christopher Eagar
Keyword(s):  
Acer Saccharum ◽  
Abies Balsamea ◽  
Fagus Grandifolia ◽  
Diameter Growth ◽  
Tree Seedlings ◽  
Betula Alleghaniensis ◽  
Hubbard Brook Experimental Forest ◽  
Tree Seedling ◽  
Soil Calcium ◽  
Dependent Growth

To assess potential forest compositional responses to exchangeable soil calcium (Caexch) and aluminum (Alexch), we characterized light-dependent growth and mortality of tree seedlings under amendments of CaCl2 and AlCl3 at Hubbard Brook Experimental Forest (HBEF), New Hampshire, U.S.A. Seedlings of Acer saccharum Marsh., Fagus grandifolia Ehrh., Betula alleghaniensis Britton, Abies balsamea (L.) Mill., and Picea rubens Sarg. were transplanted into field plots, which were randomly assigned to control, CaCl2, or AlCl3 treatments and stratified across <1 to 35% full sun. Acer saccharum and P. rubens exhibited significantly higher mortality in Al-amended than Ca-amended or control plots. Acer saccharum showed significant increases in relative diameter growth in Ca-amended plots versus controls; all other species showed nonsignificantly higher relative diameter growth under Ca amendments. We incorporated significant seedling responses into a model of forest dynamics (SORTIE) to assess potential changes in species composition under Alexch increases and Caexch losses. SORTIE predicts that further increases in Alexch would have negligible effects on canopy composition within 200 years but that the estimated Caexch depleted from HBEF between 1968 and 1995 and its influence on seedling dynamics could lead to substantial decreases in A. saccharum canopy dominance within a single forest generation (<125 years).

Seedling recruitment in a northern temperate forest: the relative importance of supply and establishment limitation

2005 ◽  
Vol 35 (4) ◽  
pp. 978-989 ◽  
Author(s):  
John P Caspersen ◽  
Megan Saprunoff
Keyword(s):  
Acer Saccharum ◽  
Temperate Forest ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Abies Balsamea ◽  
Common Species ◽  
Fagus Grandifolia ◽  
Betula Alleghaniensis ◽  
Recruitment Failure ◽  
Niche Differences

We quantified supply and establishment limitation as components of seedling recruitment for five species common to the temperate forests of central Ontario. Establishment limitation was the primary cause of recruitment failure for the three most common species: Acer saccharum Marsh., Betula alleghaniensis Britt., and Tsuga canadensis (L.) Carrière. The main barrier to establishment (including germination and seedling emergence) was a lack of suitable substrates, rather than a lack of light. Supply limitation, on the other hand, was the primary cause of recruitment failure for two less common species, Abies balsamea (L.) Mill. and Fagus grandifolia Ehrh. The cause of supply limitation was a lack of parent trees, in the case of A. balsamea, and low fecundity, in the case of F. grandifolia. Our results suggest that niche differences (i.e., germination requirements) are more important than dispersal in structuring temperate forest communities. Our results also suggest that availability of suitable substrates is the primary factor limiting seedling recruitment following logging.

Vegetation variation among mesic successional forest stands in northern lower Michigan

1988 ◽  
Vol 66 (6) ◽  
pp. 1080-1090 ◽  
Author(s):  
Mark R. Roberts ◽  
Norman L. Christensen
Keyword(s):  
Quercus Rubra ◽  
Abies Balsamea ◽  
Acer Rubrum ◽  
Pinus Strobus ◽  
Pinus Resinosa ◽  
Fagus Grandifolia ◽  
Prunus Serotina ◽  
Stand Age ◽  
Site Conditions ◽  
Soil Variables

Vegetation composition of the shrub–tree and herb layers was sampled in 70 successional aspen (Populus tremuloides and Populus grandidentata) stands of different ages (1–90 years) on a variety of sites in northern lower Michigan. Physical and chemical characteristics of soil profiles were also measured at each site. Three stand groupings were identified based on site conditions and detrended correspondence analysis (DCA) ordination of the vegetation. Sandy dry-mesic soils support forests of Acer rubrum, Quercus rubra, Pinus resinosa, and Pinus strobus. On lowland sandy soils with a fluctuating water table, Pinus strobus, Abies balsamea, Viburnum lentago, and Viburnum cassinoides are important. Mesic soils with stratified calcareous layers or clay till substrates support Acer saccharum, Fagus grandifolia, Tilia americana, Fraxinus americana, Ostrya virginiana, and Acer pensylvanicum. Canonical correlation analysis (CCA) was used to compare DCA scores with soil variables; first-axis DCA scores were correlated with a suite of soil variables and stand age was correlated with second or third DCA axis scores. Separate DCA ordinations of the dry-mesic and mesic groups revealed successional relations on these sites. On dry-mesic sites, Pinus resinosa and Pinus strobus increase in importance with stand age, while Prunus serotina, Prunus virginiana, Prunus pensylvanica, and the aspens decrease. On mesic sites, early successional species include the aspens, Corylus cornuta, Prunus serotina, and Prunus pensylvanica. Fagus grandifolia, Acer pensylvanicum, Quercus rubra, Viburnum acerifolium, Betula papyrifera, Acer rubrum, and Tilia americana are more abundant in mature mesic-site stands. Ordinations of the herb data were remarkably similar to those for trees and shrubs except on dry-mesic sites. Much of the residual variability in vegetation not accounted for by site conditions and stand age is probably related to historical factors such as the nature of disturbance and variations in seed rain.

Effects of fenitrothion on the arthropod food of tree-foraging forest songbirds

1990 ◽  
Vol 68 (11) ◽  
pp. 2235-2242 ◽  
Author(s):  
Rhonda L. Millikin
Keyword(s):  
Active Ingredient ◽  
Significant Relationship ◽  
Tree Species ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Betula Papyrifera ◽  
White Birch ◽  
Forest Songbirds ◽  
The Impact

The impact of fenitrothion on the arthropod food of songbirds was measured using white birch (Betula papyrifera Marsh.) and balsam fir (Abies balsamea (L.) Mill.) branch sample and drop trays. Following ground application of fenitrothion at 293 g active ingredient/ha, there was a significant decrease in the biomass of arthropods as determined using branch samples from both tree species, but not until 5 days after the application (29% reduction for balsam fir, 35% for white birch). Samples from drop trays indicated an immediate kill of arthropods not associated with the tree. Most remaining arthropods on treated balsam fir trees were dead. These dead arthropods would not be suitable food for birds that require movement to detect their prey. There was no significant relationship between amount of deposit (treated trees only) and the reduction of arthropods for either tree species.

Links between biomass and tree demography in a northern hardwood forest: a decade of stability and change in Hubbard Brook Valley, New Hampshire

2011 ◽  
Vol 41 (7) ◽  
pp. 1369-1379 ◽  
Author(s):  
Natalie S. van Doorn ◽  
John J. Battles ◽  
Timothy J. Fahey ◽  
Thomas G. Siccama ◽  
Paul A. Schwarz
Keyword(s):  
New Hampshire ◽  
Abies Balsamea ◽  
Total Biomass ◽  
Betula Alleghaniensis ◽  
Tree Biomass ◽  
Hubbard Brook ◽  
Tree Demography ◽  
Live Biomass ◽  
Live Tree ◽  
Annual Mortality

We resurveyed a network of sampling plots (n = 371) 10 years after its establishment in Hubbard Brook Experimental Forest (New Hampshire, USA) to quantify recent trends in tree biomass and demography. We found no significant change in live-tree biomass during the decade. Total biomass was 246 Mg·ha–1 (95%CI = 235–258) in 1995–1996 and 245 Mg·ha–1 (95%CI = 234–256) in 2005–2006. Annual mortality during the period for trees ≥ 10 cm diameter at breast height (1.37 m) averaged 9.7 trees·ha–1·year–1 (95% CI of annual mortality rate = 1.36%–1.84%·year–1). Tree recruitment into the census pool was 8.4 trees⋅ha–1·year–1 (95% CI = 5.8–10.6). Although overall forest biomass remained constant, there were marked shifts in the relative dominance of the canopy species. For example, the live biomass of Betula alleghaniensis Britton declined by 7%, whereas the live biomass of Picea rubens Sarg. increased by 6% and that of Acer saccharum Marshall increased by 4%. There was no instance of recruitment significantly exceeding mortality for the major species. Relative growth rates ranged from 1.03%·year–1 for Betula papyrifera Marshall to 1.99%·year–1 for Abies balsamea (L.) Mill. Our results confirmed earlier reports that the forest at Hubbard Brook is no longer aggrading. Current live-tree biomass is lower than expected. Although effects of novel disturbances documented on a regional level have not led to directional changes in tree demography at Hubbard Brook, we suggest that these novel stressors are depressing the biomass potential of the forest.

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