Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada
The existence of two major types of lichen woodland in Canada, Cladonia stellaris woodland and Stereocaulon paschale woodland, is discussed in relation to their seral nature and their rarely developed theoretical climax type.Our own observations, coupled with previous descriptions from a wider area,...
Published in: | Canadian Journal of Botany |
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Language: | English |
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Canadian Science Publishing
1977
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Online Access: | http://dx.doi.org/10.1139/b77-050 http://www.nrcresearchpress.com/doi/pdf/10.1139/b77-050 |
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crcansciencepubl:10.1139/b77-050 2024-09-09T19:41:50+00:00 Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada Kershaw, K. A. 1977 http://dx.doi.org/10.1139/b77-050 http://www.nrcresearchpress.com/doi/pdf/10.1139/b77-050 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Botany volume 55, issue 4, page 393-410 ISSN 0008-4026 journal-article 1977 crcansciencepubl https://doi.org/10.1139/b77-050 2024-06-20T04:11:52Z The existence of two major types of lichen woodland in Canada, Cladonia stellaris woodland and Stereocaulon paschale woodland, is discussed in relation to their seral nature and their rarely developed theoretical climax type.Our own observations, coupled with previous descriptions from a wider area, suggest that Stereocaulon paschale woodland replaces Cladonia stellaris woodland in a more or less continuous zone from just west of Churchill across to Great Slave Lake, immediately north and south of latitude 60° N. Both woodland types are often typical of sandy soils (pH 6 or less) and almost always represent the final recovery phase after fire. Rarely, the lichen surface is replaced by a continuous moss cover as the spruce canopy closes. The lichen surface is thus dependent on the lack of competition from higher plants, the absence of which is characteristic of the climate of this northern boreal region. Cladonia stellaris woodland also occurs on palsas and peat plateaux where, again, lack of higher plant competition and a suitable pH exist.The recovery sequence after fire is a highly complex process and as yet only the following parameters have been categorized. In the early recovery phases, limited soil moisture and hence a reduced summer latent heat flux enhance the sensible heat flux. The surface conditions are analogous to those of a hot desert with very high surface temperatures and extremely large diurnal temperature fluctuations. The physiology of these initial moss and lichen colonizers presumably enables them to tolerate these harsh conditions. The establishment of a few spruce seedlings and the subsequent development of open lichen woodland modulates the harsh summer temperature regime and allows the further development of a vegetated surface. After humus accumulation, which acts as an effective mulch, summer soil moisture is elevated, enhancing the latent heat flux and correspondingly reducing the sensible heat flux. This probably allows the full development of mature lichen woodland with its almost ... Article in Journal/Newspaper Great Slave Lake palsas Canadian Science Publishing Canada Great Slave Lake ENVELOPE(-114.001,-114.001,61.500,61.500) Canadian Journal of Botany 55 4 393 410 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
The existence of two major types of lichen woodland in Canada, Cladonia stellaris woodland and Stereocaulon paschale woodland, is discussed in relation to their seral nature and their rarely developed theoretical climax type.Our own observations, coupled with previous descriptions from a wider area, suggest that Stereocaulon paschale woodland replaces Cladonia stellaris woodland in a more or less continuous zone from just west of Churchill across to Great Slave Lake, immediately north and south of latitude 60° N. Both woodland types are often typical of sandy soils (pH 6 or less) and almost always represent the final recovery phase after fire. Rarely, the lichen surface is replaced by a continuous moss cover as the spruce canopy closes. The lichen surface is thus dependent on the lack of competition from higher plants, the absence of which is characteristic of the climate of this northern boreal region. Cladonia stellaris woodland also occurs on palsas and peat plateaux where, again, lack of higher plant competition and a suitable pH exist.The recovery sequence after fire is a highly complex process and as yet only the following parameters have been categorized. In the early recovery phases, limited soil moisture and hence a reduced summer latent heat flux enhance the sensible heat flux. The surface conditions are analogous to those of a hot desert with very high surface temperatures and extremely large diurnal temperature fluctuations. The physiology of these initial moss and lichen colonizers presumably enables them to tolerate these harsh conditions. The establishment of a few spruce seedlings and the subsequent development of open lichen woodland modulates the harsh summer temperature regime and allows the further development of a vegetated surface. After humus accumulation, which acts as an effective mulch, summer soil moisture is elevated, enhancing the latent heat flux and correspondingly reducing the sensible heat flux. This probably allows the full development of mature lichen woodland with its almost ... |
format |
Article in Journal/Newspaper |
author |
Kershaw, K. A. |
spellingShingle |
Kershaw, K. A. Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada |
author_facet |
Kershaw, K. A. |
author_sort |
Kershaw, K. A. |
title |
Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada |
title_short |
Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada |
title_full |
Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada |
title_fullStr |
Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada |
title_full_unstemmed |
Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada |
title_sort |
studies on lichen-dominated systems. xx. an examination of some aspects of the northern boreal lichen woodlands in canada |
publisher |
Canadian Science Publishing |
publishDate |
1977 |
url |
http://dx.doi.org/10.1139/b77-050 http://www.nrcresearchpress.com/doi/pdf/10.1139/b77-050 |
long_lat |
ENVELOPE(-114.001,-114.001,61.500,61.500) |
geographic |
Canada Great Slave Lake |
geographic_facet |
Canada Great Slave Lake |
genre |
Great Slave Lake palsas |
genre_facet |
Great Slave Lake palsas |
op_source |
Canadian Journal of Botany volume 55, issue 4, page 393-410 ISSN 0008-4026 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/b77-050 |
container_title |
Canadian Journal of Botany |
container_volume |
55 |
container_issue |
4 |
container_start_page |
393 |
op_container_end_page |
410 |
_version_ |
1809911142720471040 |