Représentation pollinique actuelle à la limite des arbres au Nouveau-Québec
Modern pollen spectra from a series of lakes in northwestern Quebec reflect the major vegetation zones of the forest–tundra transition from latitude 55°N to 59°N. Shrub tundra samples are dominated by Betula and herb pollen, whereas Picea percentages are between 10 and 20%. Lichen woodland samples c...
Published in: | Canadian Journal of Earth Sciences |
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Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1991
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Subjects: | |
Online Access: | http://dx.doi.org/10.1139/e91-055 http://www.nrcresearchpress.com/doi/pdf/10.1139/e91-055 |
Summary: | Modern pollen spectra from a series of lakes in northwestern Quebec reflect the major vegetation zones of the forest–tundra transition from latitude 55°N to 59°N. Shrub tundra samples are dominated by Betula and herb pollen, whereas Picea percentages are between 10 and 20%. Lichen woodland samples can contain over 60% Picea, with Betula and Alnus crispa each less than 20%. Pollen assemblages from the shrub subzone of the forest–tundra resemble those of the shrub tundra, while those from the forest subzone resemble lichen woodland samples. Maximum percentages of Alnus crispa are found in the forest–tundra. Classification of the samples using cluster analysis and an ordination by principal coordinates analysis suggest that densely and sparsely forested regions can be discriminated. |
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