Current status
Greater copperwort is a minute leafy liverwort which is generally found on copper-enriched substrates, including soil, walls, rocks and spoil, found around copper mines. It is ecologically similar to
C. massalongi with which it frequently occurs, but seems able to tolerate rather drier conditions. Other associates include
Gymnocolea inflata,
Pohlia annotina and
Bryum bicolor. Notable species recorded in association with greater copperwort at some localities include
C. integerrima,
Ditrichum cornubicum and
Pohlia andalusica. Capsules are unknown in greater copperwort, but the species reproduces vegetatively by gemmae which are commonly formed on the leaves.
This species has not been recorded outside Britain. In Britain it is currently known from approximately 22 sites in Cornwall, and another two sites in Devon. Several of these sites were identified during recent surveys of old mine sites in south-west England, and it is thought that several more greater copperwort sites may remain undiscovered in this area. The best known population is in eastern Cornwall where it occurs along approximately 200 m of stream side. It was also previously recorded from one site in Gwynedd, but despite recent searches has not been seen here for over 60 years.
Greater copperwort is provisionally classified as Vulnerable in Great Britain. It receives general protection under the Wildlife and Countryside Act 1981.
Current factors causing loss or decline
Encroachment of scrub and other vegetation, including shading by gorse and heather, may be a threat at some sites.
Spoil landscaping and redevelopment is a threat to extant sites.
This species is known to occur on the walls of old mine buildings. Restoration of these buildings could therefore be damaging to populations of greater copperwort.
Exploratory digging to relocate old mine shafts is a threat to populations at several sites. (This digging is generally carried out by local authorities who are anxious to replace unsafe timber cappings on old shafts.)
Current action
Two of the known greater copperwort sites in south-west England are within SSSIs.
English Nature commissioned surveys of old mine sites in west Cornwall during the winters of 1995 and 1996. A 1997 winter survey of mine sites in east Cornwall is also planned.
The Cornwall Wildlife Trust is compiling a register of rare bryophytes in west Cornwall.
Action plan objectives and targets
Maintain the geographical range of greater copperwort.
Increase the size of populations of greater copperwort where biologically feasible.
Proposed actions with lead agencies
Policy and legislation
None proposed.
Site safeguard and management
Consider notifying as SSSIs sites with viable populations of greater copperwort where this is consistent with selection guidelines, and where it is necessary to ensure their long-term protection and appropriate management. (ACTION: NE)
Undertake clearance of gorse, heather and scrub where it threatens to shade out colonies of greater copperwort. (ACTION: NE)
Assess the need to undertake some ground disturbance on greater copperwort sites, to reduce competition from encroaching vegetation. (ACTION: NE)
Exploratory digging to relocate mine shafts should only be carried out where there are real safety concerns. Where such work is necessary, expert bryological advice should be sought so that damage to greater copperwort colonies is kept to a minimum. (ACTION: NE)
Ensure that any proposals for landscaping mine spoil heaps on which greater copperwort occurs, or for redeveloping mine buildings which have colonies of greater copperwort growing on the walls, are accompanied by a conservation plan for this species, written with the guidance of an expert bryologist. The plan should set out ways to ensure the conservation of viable populations of greater copperwort during and after the work. (ACTION: NE)
Species management and protection
Depending on the results of 5.5.5, establish an ex situ collection using material derived from populations in south-west England. (ACTION: NE).
Advisory
Advise landowners and managers, and relevant agencies, of the presence and importance of greater copperwort, specific management for its conservation, and any potentially damaging actions. Landowners and managers should have access to specialist advice if needed. (ACTION: NE)
Future Research and Monitoring
Commission a survey for greater copperwort in Devon and Cornwall, concentrating on localities which have not been recently investigated. Particular care should be taken to ensure that all records are distinguished from C. massalongi, and that threats to all extant sites are assessed. The survey results should be used to refine the conservation action for this species recommended in other parts of this plan. (ACTION: NE)
Resurvey the site in Wales from which this species was formerly recorded. (ACTION: CCW)
Undertake regular monitoring of all extant populations. (ACTION: NE)
Commission research into the habitat requirements and population dynamics of this species in order to inform future conservation management. (ACTION: NE)
Undertake pilot studies to develop and refine ex situ conservation techniques for this species and other threatened bryophytes. (ACTION: NE, RBG Kew).
Communications and Publicity
Encourage bryologists to pass all records of greater copperwort, including ecological information, to a national database. (ACTION: CCW, NE, JNCC)
Liaise with specialist societies to increase the awareness and identification skills of bryologists and other naturalists in relation to this species, through publishing articles or holding identification workshops. (ACTION: CCW, NE, JNCC)
Use greater copperwort as an example of a threatened bryophyte associated with metal-rich mine spoil in order to publicise the important lower plant communities of this habitat. (ACTION: NE, JNCC)
Links with other action plans
None given.
Publication details
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume III: Plants and fungi (February 1999, Tranche 2, Vol III, p163)
Related links
ARKive Visit the ARKive website to view images and further information relating to this species