Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland
Abstract The aims were to examine the importance of regeneration by seeds, the influence of plant traits and disturbances, and the role of seed-seedling conflicts in regeneration and in the determination of vegetation structure. The study was carried out at in a subarctic alpine area (Kilpisjärvi 69...
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University of Oulu
2002
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ftunivoulu:oai:oulu.fi:isbn951-42-6861-X 2023-07-30T04:04:39+02:00 Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland Welling, P. (Pirjo) 2002-11-15 application/pdf http://urn.fi/urn:isbn:951426861X eng eng University of Oulu info:eu-repo/semantics/altIdentifier/pissn/0355-3191 info:eu-repo/semantics/altIdentifier/eissn/1796-220X info:eu-repo/semantics/openAccess © University of Oulu, 2002 seed bank seed rain seedling emergence seedling recruitment info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion 2002 ftunivoulu 2023-07-08T20:01:16Z Abstract The aims were to examine the importance of regeneration by seeds, the influence of plant traits and disturbances, and the role of seed-seedling conflicts in regeneration and in the determination of vegetation structure. The study was carried out at in a subarctic alpine area (Kilpisjärvi 69°01′N 20°50E′, Finland). Seed bank and seedling densities were high in many plant communities (ranges 99–1109 viable seeds/m² and 0.2–227 seedlings/m², respectively). Effective seedling recruitment is reflected in vegetation as a high proportion of plants with poor or no vegetative reproduction ability. This development may take place in meadows and snowbeds where herbs (e.g. Gnaphalium supinum, Sibbaldia procumbens, Veronica alpina and Viola biflora) are abundant. On the other hand, the low proportion of these plants in heath vegetation reflects ineffective seedling recruitment. Floristic similarities between the consecutive phases in the regeneration pathway may be low despite effective seedling recruitment. Clonality, large and small seed sizes and appendaged diaspores limit the movement of species from phase to phase. Generally, disturbances facilitate effective regeneration by seeds. Grazing promotes species with large seed banks and is therefore one reason for high seed bank densities. Freezing and melting processes negate a negative influence of altitude on seed bank densities in the phase of seedlings. However, if disturbances are severe and continuous and the soil is compact, unstable or dry, disturbances are not beneficial. The same is true if there is a shift in the species composition of seedlings from gaps to closed vegetation. This phenomenon occurred in a rich meadow. Seed-seedling conflicts limit regeneration by seeds in low-herb snowbeds and Ranunculus glacialis-Gymnomitrion snowbeds. Vegetative reproduction and infrequent pulses of seedling recruitment negate an influence of short-term seedling recruitment on the spatial structure of vegetation. Extreme conditions, such as low temperatures, ... Doctoral or Postdoctoral Thesis Kilpisjärvi Ranunculus glacialis Sibbaldia procumbens Subarctic Jultika - University of Oulu repository Kilpisjärvi ENVELOPE(20.767,20.767,69.034,69.034) |
institution |
Open Polar |
collection |
Jultika - University of Oulu repository |
op_collection_id |
ftunivoulu |
language |
English |
topic |
seed bank seed rain seedling emergence seedling recruitment |
spellingShingle |
seed bank seed rain seedling emergence seedling recruitment Welling, P. (Pirjo) Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland |
topic_facet |
seed bank seed rain seedling emergence seedling recruitment |
description |
Abstract The aims were to examine the importance of regeneration by seeds, the influence of plant traits and disturbances, and the role of seed-seedling conflicts in regeneration and in the determination of vegetation structure. The study was carried out at in a subarctic alpine area (Kilpisjärvi 69°01′N 20°50E′, Finland). Seed bank and seedling densities were high in many plant communities (ranges 99–1109 viable seeds/m² and 0.2–227 seedlings/m², respectively). Effective seedling recruitment is reflected in vegetation as a high proportion of plants with poor or no vegetative reproduction ability. This development may take place in meadows and snowbeds where herbs (e.g. Gnaphalium supinum, Sibbaldia procumbens, Veronica alpina and Viola biflora) are abundant. On the other hand, the low proportion of these plants in heath vegetation reflects ineffective seedling recruitment. Floristic similarities between the consecutive phases in the regeneration pathway may be low despite effective seedling recruitment. Clonality, large and small seed sizes and appendaged diaspores limit the movement of species from phase to phase. Generally, disturbances facilitate effective regeneration by seeds. Grazing promotes species with large seed banks and is therefore one reason for high seed bank densities. Freezing and melting processes negate a negative influence of altitude on seed bank densities in the phase of seedlings. However, if disturbances are severe and continuous and the soil is compact, unstable or dry, disturbances are not beneficial. The same is true if there is a shift in the species composition of seedlings from gaps to closed vegetation. This phenomenon occurred in a rich meadow. Seed-seedling conflicts limit regeneration by seeds in low-herb snowbeds and Ranunculus glacialis-Gymnomitrion snowbeds. Vegetative reproduction and infrequent pulses of seedling recruitment negate an influence of short-term seedling recruitment on the spatial structure of vegetation. Extreme conditions, such as low temperatures, ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Welling, P. (Pirjo) |
author_facet |
Welling, P. (Pirjo) |
author_sort |
Welling, P. (Pirjo) |
title |
Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland |
title_short |
Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland |
title_full |
Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland |
title_fullStr |
Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland |
title_full_unstemmed |
Regeneration by seeds and vegetation structure in alpine plant communities, subarctic Finland |
title_sort |
regeneration by seeds and vegetation structure in alpine plant communities, subarctic finland |
publisher |
University of Oulu |
publishDate |
2002 |
url |
http://urn.fi/urn:isbn:951426861X |
long_lat |
ENVELOPE(20.767,20.767,69.034,69.034) |
geographic |
Kilpisjärvi |
geographic_facet |
Kilpisjärvi |
genre |
Kilpisjärvi Ranunculus glacialis Sibbaldia procumbens Subarctic |
genre_facet |
Kilpisjärvi Ranunculus glacialis Sibbaldia procumbens Subarctic |
op_relation |
info:eu-repo/semantics/altIdentifier/pissn/0355-3191 info:eu-repo/semantics/altIdentifier/eissn/1796-220X |
op_rights |
info:eu-repo/semantics/openAccess © University of Oulu, 2002 |
_version_ |
1772816211646611456 |