Grazing was a fundamental use of lowland heathlands across the British Isles and mainland Europe until its decline in the twentieth century. Heathlands were important for cattle, pony and sheep grazing and such areas became a distinctive part of the cultural landscape in many of the southern counties of England, including Hampshire. There is considerable historic data and photographic evidence of livestock grazing on heathlands. The New Forest in southwest Hampshire is probably the most famous example and the nearest you will find today of a traditional heathland grazing scene.
Livestock use habitats on heathland sites selectively depending on a range of factors including water, shelter, forage availability and quality. The presence of livestock on heathland sites has over many years contributed to their distinctive character, the structure of habitats and the diversity of species found there. The decline in grazing management of most heathlands in the last century has upset this delicate balance and led to a loss of species diversity.
As a part of efforts to ensure the long-term maintenance of heathlands and enhance their species diversity, the re-introduction of livestock grazing to lowland heathland sites is recommended as an important method of achieving management objectives.
Grazing of livestock on heathland is beneficial in a number of ways:
At the right stocking density, it controls and reduces some invasive species such as wavy hair grass and purple moor grass that can out-compete some more beneficial species such as heather.
The ranging and foraging habits of livestock create varied habitats with different structures – creating ‘structural mosaics’. These differing niches are suitable for a wide number of species during part or all of their life cycle. Well managed grazing can help to increase species diversity. An increase in areas of bare ground is also beneficial as many insects rely on these areas for foraging and making a home. Many heathland animals require a range of habitats (tall vegetation, short vegetation, bare ground) in a small area and grazing is the most effective tool for achieving this. Sand lizards, for example, spend much of their time living in tall, mature heather but require open, sandy areas in which to lay their eggs.
Birds (for which many heathland sites are protected under UK and European law) benefit from a range of structural diversity and the increase in insect prey.
Carefully managed grazing can help to suppress scrub growth
Grazing helps to reduce the level of nutrients in ther heathland system.
A considerable number of factors must be taken into account when considering the re-introduction of grazing stock to a heathland site.
Livestock species (cattle, ponies, sheep, goats – all will produce different results) and breed. The grazing of heathlands and other conservation sites is providing an opportunity to promote and enhance the status of rare breeds of cattle (for example Belted Galloway, Highland and Dexter) which are unsuited to modern intensive agricultural systems.
Stocking density i.e. number of head of livestock required to achieve the desired effect. High grazing pressure can have an adverse effect.
Grazing season – at what time of year will grazing the site be most beneficial and for how long, and consideration of other factors that change seasonally for example the availability of water.
Practical issues such as the type of inclosure needed and the cost, the provision of water supply, areas for over-wintering stock (if necessary), day to day responsibility for monitoring stock and veterinary fees.
Monitoring the effectiveness of grazing in achieving management objectives
Baseline monitoring is essential in order to be able to assess the effects of grazing.
Changes in heathland vegetation type should be mapped, plant structure measured (e.g. sward height) and key plant, invertebrate and vertebrate species monitored. Fixed point photograhs are useful indicators of change.
Further research is required to look at the comparison of different grazing regimes and species of grazing animal. Studies of the habitat selection and ranging behaviour of livestock would also be beneficial and some work has already been undertaken on heathlands in Holland and Denmark to investigate this. The effects on other heathland species, for example reptiles and the effects on bracken and other scrub also require further scientific research.
English Nature (now Natural England) commissioned a report co-authored by the Hampshire Grazing Project looking at methods for heathland managers to assess the ecological impacts of the re-introduction of grazing on their sites - ‘Grazing Heathland: A guide to impact assessment for insects and reptiles’ (report number 497) is available to download from Natural England's website.
Some heathlands in Hampshire that are grazed include: The New Forest, Netley Common in Southampton, Hamble Common, Bartley Heath near Hook, Elvetham Heath and Fleet Pond Heath, Castle Bottom National Nature Reserve near Eversley, Silchester Common near Tadley, Tadley Common, Bramshott Chase near Hindhead, Long Valley and Caesar's Camp near Fleet/Aldershot, and Woolmer Forest near Liphook.
In 2006 a new grazing partnership between the Hampshire and Isle of Wight Wildlife Trust (HIOWWT) and the Ministry of Defence (MOD) was set up. This focuses aims to introduce cattle grazing to the large heathland blocks which have survived owing to their use for military training.
English Nature Research report 422 – Impacts of livestock grazing on lowland heathland. (Lake, Bullock & Hartley 2001).
English Nature Research report 497 – Grazing Heathland: A guide to impact assessment for insects and reptiles
The RSPB’s ‘Conservation grazing on lowland heaths’