Norfolk's Biodiversity

Species Action Plans - Tower Mustard
(Arabis glabra)

Home

Action Plans

Species action plans

Habitat action plans

Current Status
Current factors causing loss or decline in Norfolk
Current Action In Norfolk
Action Plan Objectives and Targets

(Photo Credit: Neal Armour-Chelu)

Ref 2/S20	Species Action Plan 20
Plan Author:	Norfolk Wildlife Trust
Plan Co-ordinator:	Heathland BAP Topic Group
Plan Leader:	Forestry Commission
February 2007	Final Draft

Click to view the
Tower Mustard Action Plan

Current Status

National Status

Although tower mustard has been recorded from a total of 133 10km squares, this declined to 28 squares between 1987 and 1999 (Preston et al, 2002). According to Plantlife, the current area occupied by the species is only 15% of its total historic area. The most significant cause of decline has been agricultural intensification on heathlands.
Extant sites occur within East Anglia (Breckland), the Midlands (Severn & Avon Vales) and southern England; west Norfolk is a particular stronghold. The species is widespread elsewhere in Europe, and is also found in western Asia.
In Great Britain, tower mustard is now classified as Endangered. It receives general protection under the Wildlife and Countryside Act 1981.

Norfolk Status

Almost confined to Breckland, tower mustard was found in 17 sites in Norfolk between 1988 and 1999. The majority of these sites are in forest rides, where the species can be abundant in some places. Forestry Commission records for the period 2000 to 2006, are given below:

Site	2000	2001	2002	2003	2004	2005	2006
Didlington Springs*			0	0	0	1	0
Stanton St/Harling Drove	79					155	118
Stanton St				1797	617	149	32
FR24							1
Barrow Hill					1
4Score Plantation*			2	0	8
Ickburgh*		400*
Thetford-Danepak	17*
Barnham Cross	157
Harling Drove/Tunnel Track				26	10
BromeHill Farm				0

*Indicates ephemeral site.

Tower mustard has been able to colonise some areas of newly created habitat in Breckland, such as clear-felled conifer plantations. It is possible that the species may actually be increasing in numbers on some existing sites in Breckland where appropriate management is taking place. New and often ephemeral sites are frequently being discovered in forested areas due to translocation of tower mustard seed by forestry equipment.
Despite the implementation of appropriate management at Maine Road, the population of tower mustard at this site is in decline.

Current factors causing loss or decline in Norfolk

Habitat destruction as a result of agricultural intensification and building development. The former would appear to be the main reason for the decline of this species in recent years. However, the colonisation of a few newly created sites in Breckland has helped to slow the overall decline of the species.
Habitat neglect, which results in a lack of open ground for regeneration and the development of coarse competing vegetation.
Overgrazing by rabbits, stock and deer. Although tower mustard is a Breckland species, there is evidence that it is susceptible to high levels of grazing.

Current Action in Norfolk

The majority of sites are owned, managed and monitored by the British Trust for Ornithology, Plantlife or the Forestry Commission, and appropriate management is undertaken on all key (not ephemeral) sites where tower mustard occurs.
On sites that are not owned by the above mentioned organisations (e.g,. Barnhamcross Common, Seven Hills, Brettenham and Maine Road/Brandon Road sites), landowners are advised on appropriate land management for tower mustard.
The Brandon Road site has been designated as a Roadside Nature Reserve.
The Maine Road site is managed by the developer in conjunction with the Brecks Countryside Project, but has declined and further management is required.
Plantlife is currently carrying out an ecological study of tower mustard at Ickburgh. This includes experiments to investigate the response of tower mustard to various cultivation techniques. PhD student Jo Nightingale from the University of Sussex is studying the ecology and population dynamics of tower mustard from sites in Breckland.
The identification of new and often ephemeral sites continues; these are frequently being discovered in forested areas due to translocation of tower mustard seed by forestry equipment.

Action Plan Objectives and Targets

National

Maintain the current (natural) range within twenty-six 10km squares.
Establish populations at three sites within the historic range by 2010.
Establish four meta-populations within the species current range by 2010.

Norfolk

As a minimum threshold, maintain the natural range of this species at or above 14 tetrads.
Establish populations at two new sites within the species' historic range by 2010.

Send mail to scott.perkin@norfolk.gov.uk with questions or comments about this web site. This page was printed from the Norfolk Biodiversity Website : http://www.norfolkbiodiversity.org/

Species Action Plans - Tower Mustard (Arabis glabra)