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Forskingsresultat
frå Lyngheiene på Lygra
Prescribed
burning and the role of seed banks in post-fire
succession of northern heathlands,Lygra and Lurekalven
islands, Hordaland, Norway
Inger E. Måren & Vigdis
Vandvik
Department
of Natural History, University of Bergen, Allégaten 41,
N-5007 Bergen, Norway
Department of Biology, University of Bergen, Allégaten
41, N-5007 Bergen, Norway
SUMMARY
Variation
in plant species composition, abundance of seeds in the
soil seed bank and standing vegetation, over
the
course of a post-fire succession was investigated in
coastal Calluna-heathlands
in Western Norway.
Vegetation
and seed banks were analysed over a 24-year post-fire
period. The total diversity of vegetation and
seed
bank were 60 and 54 vascular plant taxa respectively (39
shared species), resulting in 68% similarity. Over
the
24 years the heathland community progressed from open
newly-burnt ground via species rich graminoid- and
herb-dominated
vegetation to mature heather Calluna
vulgaris-dominated
heath. This post-fire succession was
not
reflected in the seed bank; the 10 most abundant species
constituted 98% of the germinated seeds. The most
abundant
were Calluna (49%;
12,018 seeds/m2) and cross-leaved heath Erica
tetralix (34%; 8,414
seeds/m2).
Calluna
showed
significantly higher germination in the two first years
following burning. Vegetation species
richness
(ranging 23 to 46 species/yr) was highest in the middle
years of the post-fire succession period. In
contrast,
the seed bank species richness (21 to 31 species/yr)
showed no trend. This suggests that the seed bank
act
as a refuge, providing a source of recruits for many
species that colonize newly-burnt areas. The traditional
management
regime has not depleted or destroyed the seed banks, and
continuing management is necessary to
ensure
perpetuation of the heathlands.
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Publisert
i Consevation Evidence
-

Inger
Elisabeth Måren

Vigdis
Vandvik
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