scholarly journals Myrtle Lake: a late- and post-glacial pollen diagram from northern Minnesota

1968 ◽  
Vol 46 (11) ◽  
pp. 1397-1408 ◽  
Author(s):  
C. R. Janssen
Keyword(s):  
Pinus Banksiana ◽  
Deciduous Forest ◽  
Typha Latifolia ◽  
Pinus Strobus ◽  
Larix Laricina ◽  
Fraxinus Pennsylvanica ◽  
Pollen Diagram ◽  
Raised Bogs ◽  
Ostrya Virginiana ◽  
Lake Waters

A pollen diagram from a lake in the former bed of the eastern arm of Lake Agassiz in northern Minnesota records a vegetation of spruce forest followed by immigration successively of Pinus banksiana and (or) P. resinosa at 10 000 B.P., then Abies and Pteridium, and still later Alnus. Between 8000 and 7000 B.P. prairie and (or) Quercus savanna prevailed on the uplands, followed by deciduous forests of mainly Quercus, Ostrya virginiana, Fraxinus pennsylvanica, and possibly Populus sp.Slightly later, Pinus strobus migrated into the area, resulting in a gradual decline of pollen of deciduous forest types. Betula pollen, however, rises, and there is an indication of a return to prairie conditions prior to 3000 B.P.During the 8000–7000 B.P. dry interval the lowland vegetation consisted of fens of Typha latifolia, Dryopteris thelypteris, and Cyperaceae. Later paludification and lateral expansion of the peatland gave rise to rather rich swamps of Picea mariana, Larix laricina, Alnus rugosa, and Thuja occidentalis. There are some conspicuous peaks of Myrica in the pollen diagram.The time after 3000 B.P. is characterized by much Pinus strobus pollen and minima of deciduous trees and herbs. In the lowlands, formation of raised bogs and poor swamps and fens began, indicating a shift in climate towards wetter conditions. The arrival of white man in the area is reflected by the rise of Ambrosia. The shifts in overall peatland types are clearly accompanied by changes in the species composition of Pediastrum in Myrtle Lake, indicating corresponding changes in the lake waters.

scholarly journals Late-winter habitat use by the Fisher, Pekania pennanti (Erxleben, 1777), in the Boreal Plains Ecozone of northwestern Saskatchewan, Canada

2014 ◽  
Vol 128 (3) ◽  
pp. 272 ◽  
Author(s):  
Gilbert Proulx
Keyword(s):  
Habitat Use ◽  
Deciduous Forest ◽  
Late Winter ◽  
Larix Laricina ◽  
Forest Stands ◽  
Habitat Types ◽  
Winter Habitat ◽  
Boreal Plains ◽  
Pekania Pennanti ◽  
Crown Closure

Late-winter habitat use by the Fisher, Pekania pennanti (Erxleben, 1777) in northwestern Saskatchewan was assessed in February 2009, 2011, and 2012. A total of 78 Fisher tracks were recorded over 60 300 m of snowshoe surveys. Fisher tracks were significantly less frequent than expected in Tamarack (Larix laricina [Du Roi] K. Koch) stands with > 40% crown closure and mainly 0–10 m trees (P < 0.05) and in open areas. Fishers used other habitat types equal to availability, including muskeg and coniferous, mixed, and deciduous forest stands. Maintaining mosaics of forest stands of different seral stages interspersed with muskeg would meet the late-winter habitat needs of Fishers in the Boreal Plains Ecozone of northwestern Saskatchewan.

A Petri dish technique for the aseptic synthesis of ectomycorrhizae

1989 ◽  
Vol 67 (6) ◽  
pp. 1713-1716 ◽  
Author(s):  
Ken K. Y. Wong ◽  
J. André Fortin
Keyword(s):  
Pinus Banksiana ◽  
Petri Dish ◽  
Microbial Interactions ◽  
Laccaria Bicolor ◽  
Larix Laricina ◽  
Hebeloma Cylindrosporum ◽  
First Order ◽  
Whole Plants ◽  
Improved Technique ◽  
Physiological And Biochemical

An improved technique was developed for the aseptic synthesis of ectomycorrhizae in Petri dishes. Within 2 weeks after inoculation of a first-order lateral, ectomycorrhizae were formed on Larix laricina and Pinus banksiana with Hebeloma cylindrosporum, Laccaria bicolor, and Pisolithus tinctorius. The technique should be useful for addressing physiological and biochemical questions concerning microbial interactions with roots of whole plants.

A 12,000-Year History of Vegetation and Climate for Cape Cod, Massachusetts

1985 ◽  
Vol 23 (3) ◽  
pp. 301-312 ◽  
Author(s):  
Marjorie Green Winkler
Keyword(s):  
Pinus Banksiana ◽  
Vegetation History ◽  
Sediment Cores ◽  
Pinus Strobus ◽  
Cape Cod ◽  
Pine Barrens ◽  
Conifer Forest ◽  
Climate History ◽  
History Of ◽  
Vegetation And Climate

Pollen and charcoal analysis of radiocarbon-dated sediment cores from Duck Pond in the Cape Cod National Seashore provide a continuous 12,000-yr vegetation and climate history of outer Cape Cod. A Picea-Hudsonia parkland and then a Picea-Pinus banksiana-Alnus crispa boreal forest association grew near the site between 12,000 and 10,000 yr B.P. This vegetation was replaced by a northern conifer forest of Pinus strobus-P. banksiana, and, subsequently, by a more mesophytic forest (Pinus strobus, Tsuga, Quercus, Fagus, Acer, Ulmus, Fraxinus, Ostrya) as the climate became warmer and wetter by 9500 yr B.P. By 9000 yr B.P. a Pinus rigida-Quercus association dominated the landscape. High charcoal frequencies from this and subsequent levels suggest that the pine barrens association developed during a warmer and drier climate that lasted from 9000 to about 5000 yr B.P. Increased percentages of Pinus strobus pollen indicate a return to moister and cooler conditions by about 3500 yr B.P. A doubled sedimentation rate, increased charcoal, and increased herb pollen suggest land disturbance near the pond before European settlement. These results suggest a rapid warming in the northeast in the early Holocene and support a hypothesis of a rapid sea level rise at that time. Comparison of the pollen results from Duck Pond with those from Rogers Lake, Connecticut, illustrates the importance of edaphic factors in determining the disturbance frequency and vegetation history of an area.

Holocene history of forest trees in southern Ontario

1987 ◽  
Vol 65 (9) ◽  
pp. 1792-1801 ◽  
Author(s):  
K. D. Bennett
Keyword(s):  
Acer Saccharum ◽  
Pinus Banksiana ◽  
Late Holocene ◽  
Accumulation Rate ◽  
Pinus Strobus ◽  
Fagus Grandifolia ◽  
Forest Trees ◽  
Southern Ontario ◽  
History Of ◽  
Available Information

Three new Holocene pollen percentage and accumulation rate diagrams for southern Ontario are presented. They greatly increase the available information on the history of the area's forest trees and permit a discussion of the competitive interactions that have brought about the forest pattern seen today. In the earliest Holocene, the forests were dominated by Picea, which was replaced by first Pinus banksiana–resinosa and then Pinus strobus. In extreme southern Ontario, Pinus strobus was replaced by Acer saccharum and Fagus grandifolia, but in the area east of Georgian Bay, Tsuga canadensis became the dominant, and near Mattawa, Betula (probably lutea). Late Holocene stability of forests is considered to be a function of the lack of taxa better able to compete than those already present.

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.

The role of wound periderm in the resistance of eastern larch and jack pine to dwarf mistletoe

1971 ◽  
Vol 49 (4) ◽  
pp. 501-504 ◽  
Author(s):  
F. H. Tainter ◽  
D. W. French
Keyword(s):  
Pinus Banksiana ◽  
Jack Pine ◽  
Larix Laricina ◽  
Dwarf Mistletoe ◽  
Resistance Reaction ◽  
Relative Scarcity

Formation of wound periderm appears to be a common form of resistance reaction in the Arceuthobium pusillum – Larix laricina combination, based on previous observations and an extensive examination of two witches' brooms of this host. Not only is wound periderm common in spur shoots within witches' brooms, but it also apparently restricts the development of the endophytic system in branchlets composing witches' brooms. Branchlets within witches' brooms of Pinus banksiana infected with A. pusillum and A. americanum also produced wound periderm similar to that described in eastern larch, which may account for the relative scarcity of aerial shoots on this host and restricted development of the endophytic system.

Vegetation changes through time on islands of Lake Duparquet, Abitibi, Canada

2000 ◽  
Vol 30 (2) ◽  
pp. 179-190 ◽  
Author(s):  
I Larocque ◽  
Y Bergeron ◽  
I D Campbell ◽  
RHW Bradshaw
Keyword(s):  
Picea Mariana ◽  
Pinus Banksiana ◽  
Pinus Strobus ◽  
Vegetation Changes ◽  
Fire Occurrence ◽  
Vegetation Communities ◽  
Fire Intervals

Succession after fire has mainly been studied by chronosequence, which does not allow study of pre- and post-fire communities at the same site. By using palynology and anthracology, we recovered vegetation communities and fire histories through time on islands of Duparquet Lake, Canada. We show that succession after fire is dependent on interval between two fires (evaluated with depth of humus between subsequent fires). Sites with high fire occurrence show a cyclic succession (same species reappearing after fire), while sites with low fire occurrence show a directional succession. Different fire intervals lead to different pre- and post-fire pollen assemblages. During longer fire intervals, pollen assemblages change from Pinus banksiana Lamb. domination to Pinus strobus L. and Picea mariana (Mill.) BSP domination. When fire intervals are short, Pinus banksiana dominates both pre- and post-fire assemblages.

scholarly journals Breeding Bird Communities in Boreal Forest of Western Canada: Consequences of “Unmixing” the Mixedwoods

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 759-769 ◽  
Author(s):  
Keith A. Hobson ◽  
Erin Bayne
Keyword(s):  
Boreal Forest ◽  
Populus Tremuloides ◽  
Pinus Banksiana ◽  
Deciduous Forest ◽  
Black Spruce ◽  
Bird Species ◽  
White Spruce ◽  
Trembling Aspen ◽  
Vegetation Heterogeneity ◽  
Mixedwood Stands

Abstract Silvicultural practices following clearcutting in boreal forest may encourage the creation of monospecific, single-aged stands having less vegetation heterogeneity and diversity than original stands. We conducted point counts in central Saskatchewan, Canada, 1993–1995, in pure and mixedwood stands dominated by black spruce (Picea mariana), jackpine (Pinus banksiana), trembling aspen (Populus tremuloides), or white spruce (Picea glauca). Mixedwood stands supported more individuals and more species than pure stands. Higher abundance in mixedwood stands relative to pure stands was consistent among nesting guilds and migration strategies. Rarefaction revealed similar patterns, although pure trembling aspen stands were predicted to support more species than aspen-dominated mixedwood stands. Increased avian diversity in mixedwood stands was not solely the result of the mixing of bird species associated with coniferous or deciduous forest types. Chipping Sparrow (Spizella passerina), Pine Siskin (Carduelis pinus), White-winged Crossbill (Loxia leucoptera), Red-breasted Nuthatch (Sitta canadensis), Swainson's Thrush (Catharus ustulatus), and Tennessee Warbler (Vermivora peregrina) were more abundant in mixedwood stands than pure stands. Black-throated Green Warbler (Dendroica virens), Magnolia Warbler (D. magnolia), and Blackburnian Warbler (D. fusca) were abundant in stands dominated by white spruce but were absent from jackpine or black spruce. Other species such as American Redstart (Setophaga ruticilla) and Chestnut-sided Warbler (D. pensylvanica) relied exclusively on pure trembling aspen, particularly stands with dense shrub cover. Several bird species in the boreal forest will be adversely affected by forestry practices that target mature to old aspen and white spruce mixedwoods and promote reduction in mixedwood compositions of regenerating stands.

Coniferin, a biochemical indicator of commitment to tracheid differentiation in conifers

1989 ◽  
Vol 67 (9) ◽  
pp. 2663-2668 ◽  
Author(s):  
Rodney Arthur Savidge
Keyword(s):  
Acetic Acid ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
High Performance ◽  
Wood Formation ◽  
Defined Medium ◽  
Naphthalene Acetic Acid ◽  
Larix Laricina ◽  
Tracheid Differentiation

Endogenous E-coniferin was characterized chemically and found to accumulate in cambia of Picea glauca, Pinus banksiana, Pinus strobus, and Larix laricina at the time of resumption of springtime cell-division activity and well before the initiation of lignification in differentiating tracheids. Coniferin content, quantified by high performance liquid chromatography, was highest on the centripetal side of the cambium, in developing xylem, at time of radial expansion of cambial derivatives. Stem ringing resulted in coniferin accumulation above the ring and disappearance below the ring. Coniferin was absent from leaves and dormant cambia. Exogenous coniferin was metabolized rapidly by in vitro cultures of P. strobus cambium grown on a defined medium containing the auxins 1-naphthalene acetic acid and indol-3-yl acetic acid and the cytokinin benzylaminopurine. The evidence suggests coniferin content of the cambium will be of practical value for determining commitment to and competence for wood formation in conifers.

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