The endemic subspecies of perennial knawel is a biennial or short-lived perennial of semi-open, very short grassy heaths, compacted tracks and abandoned arable land, generally on acidic, sandy soil. It is a poor competitor, and open soil is required for seedling establishment. Flowers may appear at any time during the year, but are mainly produced between June and September.
This has never been a widespread plant and it has suffered a marked decline over the last 50 years. It is now restricted to the southern part of Breckland and has become extinct in Norfolk. There are three extant sites remaining and only one of these supports large numbers of plants.
This endemic subspecies of perennial knawel is classified as Endangered and is given special protection under Schedule 8 of the Wildlife and Countryside Act 1981.
Current factors causing loss or decline
The factors listed below were associated with the decline of this species and are now constraints on its recovery:
Increased use of herbicides and fertilisers.
The destruction of field-margin refuges.
The abandonment of marginal arable land and heathland.
Afforestation of former sites and potential sites for colonisation.
Deterioration of former and potential sites due to inappropriate grazing.
Loss of sites to building developments.
This species is currently included in English Nature`s Species Recovery Programme and the following actions have been undertaken to date:
Management of all remaining sites for this species, including grazing and periodic rotovation.
Plants are being introduced to three new sites. Drought and rabbit damage have caused some losses, but the introduction programme is continuing.
Establishment of a seed collection at RBG Kew. Plants are also being propagated ex-situ in a private collection for use in future reintroductions.
Regular monitoring of all extant and restored sites.
All three extant populations are protected within SSSIs.
Action plan objectives and targets
Restore and maintain viable populations at all extant sites.
Establish populations at three new sites by 2003.
Facilitate natural colonisation of further sites.
Proposed actions with lead agencies
Policy and legislation
Ensure that the requirements of this taxon and other elements of the Breckland flora are fully considered when deciding on future forestry management and expansion near to extant sites. (ACTION: NE, FA, FE)
Take account of the requirements of this taxon when reviewing the Breckland ESA scheme. (ACTION: NE, MAFF)
Site safeguard and management
Ensure that all extant and restored sites receive management which is beneficial to the conservation of this Breckland subspecies of perennial knawel as detailed under the Species Recovery Programme. (ACTION: NE)
Seek to develop a network of suitable habitats within the vicinity of extant populations which will provide opportunities for the spread of this taxon. Favourable management could include options under the Breckland ESA. (ACTION: NE, MAFF)
Ensure that all extant and restored sites are protected from housing development and damaging agricultural operations. (ACTION: NE, LAs)
Species management and protection
Continue with work detailed under the Species Recovery Programme for this taxon. (ACTION: NE)
On extant and restored sites for perennial knawel in Breckland, advise landowners and managers of its importance and appropriate management for its conservation. (ACTION: NE)
Advise the Breckland ESA project officer and members of the regional agri-environment consultation group of locations for this taxon, its importance and management needed for its conservation, including the need to create suitable habitat within the vicinity of extant and restored sites where opportunities arise. (ACTION: NE, MAFF)
Future Research and Monitoring
Continue with regular monitoring of extant and restored sites as detailed under the Species Recovery Programme. During these monitoring visits the opportunity should be taken to advise landowners and managers on appropriate management. (ACTION: NE)
Investigate the autecology of this subspecies with a view to informing restoration management. Priorities should include seed-bank dynamics and the optimal timing for, and methods of, ground disturbance. (ACTION: NE, JNCC)
Communications and Publicity
Raise awareness among local people of the importance of this endemic taxon and other rare species of the Breckland flora, the reasons for their decline, and action needed to secure their recovery. (ACTION: NE)
Links with other action plans
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume I: Vertebrates and vascular plants (June 1998, Tranche 2, Vol I, p233)