Bracken management not control – a sign of the times?

Written by Henrietta Appleton, Policy Officer (England)

Bracken¹ has become a contentious subject for land managers, whilst it has some benefits, where it is invasive and becomes dominant it can have a range of negative impacts which have required its perpetual control through both chemical and mechanical means.

Bracken is traditionally considered to expand its ground coverage by 1-3% per annum. But due to climate change and changes in land management/land use its rate of encroachment is accelerating. This is leading to increased concerns about its impacts on the environment, human health and wildlife:

1. Encroachment into semi-natural habitats such as peatlands, heathlands and species-rich grasslands thereby also arguably affecting the delivery of vital ecosystem services such as carbon storage and sequestration, and biodiversity. Bracken is also a key flammable fuel in wildfire and is associated with higher fire temperatures.
2. Livestock farming through reduced grazing areas although the main concern is its impact on livestock health. The toxins in the bracken may cause serious illness and even death in stock animals consuming its rhizomes or fronds whilst the litter provides an ideal moist, warm habitat for sheep ticks.
3. Archaeology and the historic environment. Historic England has identified it as a primary threat to the integrity of many scheduled monuments, particularly in the north and south-west of England.
4. Human health both through the direct effects of bracken toxins and the indirect effects of harbouring ticks given that associated tick-borne diseases are increasing.
5. Recreation and access as its presence on footpaths can be a deterrent to public access as well as concerns about contracting tick-borne diseases. Many National Parks provide information about tick awareness.

Bracken control therefore will only become more important.

Consequently, it was extremely disappointing that last October the manufacturers withdrew their support for the re-registration of the chemical Asulox in the UK (it is also not approved for use in the EU), given that the costs of continuing to prove its safety were not being covered by sales (the latter not being aided by the withdrawal of emergency authorisations in Scotland, Wales and Northern Ireland in 2023). This means that the only selective chemical control option is now lost to UK land managers. Chemical control with Asulox and appropriate follow up treatment can achieve 98% success. Glyphosate remains an option, but this is non-selective and so will remove other vegetation types, which can expose soil to erosion, particularly on slopes where non-chemical control is impossible.

The Bracken Control Group (BCG) believes that the loss of Asulox requires a reappraisal of how the impacts of bracken expansion and the increasing threats can be mitigated through options for its management. There has been little research into the effectiveness of physical control methods. But it is generally accepted that such an approach requires consistent effort over several years and can be both difficult and expensive in certain terrains.

It is therefore encouraging that the UK’s conservation bodies have commissioned an update to the practitioner guidance, which was published in October 2008. The original guidance included both mechanical and chemical methods. The BCG is working with Fera Science Ltd to provide some preliminary guidance by the end of May at which point it will be the subject of stakeholder consultation the results of which will be included in future updates. The guidance will be part of the formulation of a UK Bracken Strategic Framework over the next 12-18 months.

Natural England (NE) should also look to follow Historic England in funding and supporting research into the best methods for managing bracken to conserve our semi-natural habitats.

Bracken encroachment is a problem in 17 of the 19 groups of semi-natural sensitive habitats occurring in the British Isles and reducing its cover to less than 10% in some habitats such as dwarf shrub heath is a pre-requisite in determining favourable condition.

As the Environmental Land Management Scheme (ELMS) is aimed at protecting the environment in the face of market failure, the recently announced combined Sustainable Farming Incentive (SFI) and Countryside Stewardship (CS) options to support land managers in bracken management to restore more biodiverse habitats are welcomed, especially as it is likely that long term programmes based on initial multiple treatments followed by ongoing management will be needed which are costly. However there seems little encouragement to adopt these measures! In addition the RPA has just issued a letter to CS agreement holders that offers three options - the use of glyphosate (if approved by NE/Forestry Commission in the CS application stage), replacing chemical control (SB4) with mechanical control (SB5) and removing chemical control from the agreement. This appears to have been sent without consultation with NE.

There is even an argument to suggest that government funding support should go beyond habitat protection and consider the need for bracken control/management for public health reasons. Increased public access to the countryside is increasing the public’s exposure to tick-borne diseases and there is evidence that tick densities are higher in bracken areas than other vegetation types such as heather. The recent UK Health Security Agency report on the effects of climate change on health warned of an increase in the distribution of several tick species and the risk of Lyme disease and tick-borne encephalitis.

As this blog highlights, the increasing threat of bracken and the reduced ability to control it is a concern for a wide variety of reasons. But in many ways the concern goes beyond just bracken. This decision alongside others to reduce the toolkit available for vegetation management as well as policy support for extensification and rewilding is evidence of the wider trend within land management policy for reduced management and fewer interventions. Management has become synonymous with intensification whereas in fact it should be considered part of caring for our land. A worrying sign of the times.

¹Bracken Pteridium aquilinum is the largest of our native ferns which spreads by underground rhizomes and the dispersal of spores. It is thought to be the most common plant in the world as it is found on all continents other than Antarctica. In the UK it is found mainly in woodland and heathland but can encroach into other upland habitats.