Oblong woodsia is asmall, tufted fern found in Britain in tree-less, rock habitats above 350 m, mainly on cliffs and crags but occasionally on stable screes. In other parts of the world it grows on similar habitats although these are usually in the woodland zone and sometimes in lowland and even coastal areas.
Currently there are fewer than 100 plants known in the UK, distributed between 11 sites (6 in Scotland, 1 in England and 4 in Wales), and 5 broad localities (Highland, Tayside, Dumfries, Cumbria and Gwynedd). The plant was eliminated from at least eight sites in Cumbria, Durham and Dumfries when fern collecting was popular during the Victorian era. Today, all colonies are declining or are at best stable, and all except the colony in Cumbria (around 80 plants) are extremely small (only 1-7 plants). Despite the availability of apparently suitable habitats, there is no evidence of regeneration, recruitment, or spread at any site in Britain. Oblong woodsia is widespread in the boreal regions of North America and Europe/Asia but rare in Europe south of Scandinavia.
In GB oblong woodsia is classified as Endangered. It is specially protected under Schedule 8 of the Wildlife and Countryside Act 1981.
Current factors causing loss or decline
British populations, being at the edge of the range, may be particularly vulnerable to recent climatic changes. Prolonged summer drought has been seen to cause frond desiccation and spore abortion.
It is assumed that the oblong woodsia, like other very rare ferns with small populations, is still at some risk from collectors.
There is no evidence of recruitment at British populations of this species but the factors responsible for this are not yet clear. It has been speculated that the climate at its sites may now be unsuitable or that collecting may have affected the genetic variation in the species.
Oblong woodsia is included in SNH`s Species Action Programme and is to be included in NE`s Species Recovery Programme.
All colonies are within SSSIs; three are within NNRs.
Spores were collected, under license, from most sites in 1996 and placed in a spore-bank at RBG Edinburgh. Attempts are being made to establish ex-situ collections of sporophytes from these spores.
Two sporophytes have been collected under licence from NE for growing at the RBG Edinburgh.
The ecology and reproductive biology of oblong woodsia is being investigated by RBG Edinburgh and the University of Edinburgh.
Action plan objectives and targets
Maintain populations at all remaining sites.
Reverse decline of three populations by 2008.
Restore populations at three former sites by 2003.
Proposed actions with lead agencies
Policy and legislation
No action proposed.
Site safeguard and management
At three sites threatened with extinction, experimentally implement practical recommendations, resulting from research in 5.5.3, in an effort to reverse declines. (ACTION: CCW, RBG Edinburgh, SNH)
Species management and protection
Establish ex-situ collections of spores and sporophytes ensuring that collections do not further reduce likelihood of recruitment. If stocks permit, make spores and/or plants available to specialist horticultural outlets and fern enthusiasts to reduce any temptation to collect from the wild. (ACTION: RBG Edinburgh)
Restore populations to three former sites (identified in 5.5.2 as suitable) by 2003. (ACTION: CCW, NE, RBG Edinburgh, SNH)
If methods of improving natural recruitment fail (see 5.2.1) or cannot be defined, carry out reinforcement of three populations threatened with imminent extinction, ensuring that any period of ex-situ cultivation does not lead to any reduction in the genetic variation of introduced material. (ACTION: CCW, NE, RBG Edinburgh, SNH)
Ensure that landowners at all remaining sites are aware of the presence and significance of this species. (ACTION: CCW, NE, SNH)
Future Research and Monitoring
Ensure that the location of all individuals at known populations is recorded and monitor their fate at regular intervals to assess damage, patterns of survival, and viable spore production. Monitor suitable adjacent areas for recruitment. (ACTION: CCW, NE, SNH)
Survey all former sites to confirm that the species is absent and report on the suitability of sites for reintroduction. (ACTION: CCW, NE, SNH)
Complete research on the reproductive biology and ecology of oblong woodsia to identify causal agents of decline and propose practical measures to circumvent them. (ACTION: RBG Edinburgh)
Carry out investigations of genetic variation in existing populations of oblong woodsia (if this can be done without threatening them further) to determine if loss of genetic variation might be inhibiting recruitment, and to guide management and reintroduction policies. (ACTION: CCW, NE, RBG Edinburgh, SNH)
Communications and Publicity
Incorporate oblong woodsia in education programmes on rare British plants. (ACTION: CCW, NE, RBG Edinburgh, RBG Kew, SNH)
Links with other action plans
The following LBAPs are working on Woodsia ilvensis:
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume I: Vertebrates and vascular plants (June 1998, Tranche 2, Vol I, p261)
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