Atlas Of Ferns Of The British Isles

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27.7
DRYOPTERIS
CRISTATA
Crested
Buckler - fern
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9
CHANNEL ISLANDS
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UTM GRID
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27.7 Dryopteris cristata (L.) A.Gray
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A northern continental species at one time frequent in the east
of England and N.W. Midlands. Now, because of changes in
land-use and increasing drainage of acid mires, it is almost
restricted to East Anglia where it is locally frequent in the
Norfolk Broads area, v.c. 27. Lack of regular fen cutting allows
tussock growth of Molinia, Carex elata and Sphagnum spp.
upon which establishment of D.cristata depends and the
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HW N2
ASPIDIACEAE
decrease of such mowing may be encouraging this species to
regain its status. There has been recently a widespread increase
of acid (base-poor) plant communities (including Sphagnum
Jimbriatum, S.magellanicum, S.palustre, S.squarrosum and
S.subnitens) in the fens of the Norfolk Broads, the ecological
reason for which is not fully understood. It is in these
communities that D.cristata becomes well established.
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