Kirsty Brown – Conservation Project Assistant and Alex Cripps – Conservation Graduate Trainee
Conservation grazing as a management technique: how does it work, when do we use it and what animals do we use? These are all questions we discussed during a recent Grazing for Site Conservation Management course held at Plas Tan y Bwlch, Snowdonia National Park’s Study Centre.
Why use grazing?
Conservation grazing can be an important tool for habitat management and works in three main ways:
- defoliation by grazing and browsing vegetation;
- trampling by treading and breaking up vegetation;
- dunging/urinating by recycling materials back into the system.
The combination of these three processes, along with understanding the ways that different animals graze can help manage and extend important habitats.
Grazing is the traditional way of managing hay meadows (species rich grassland). Surviving meadows have an increased fungi:bacteria ratio, when compared to improved grasslands, as fertilizers increase bacterial levels which result in less healthy soils. The addition of any type of artificial fertiliser has a negative effect. Controlling the grazing e.g. shutting the animals out of a meadow in the summer is vital to allow the plants to flower and set seed without being eaten. Where the hay meadows are shut in summer, a later shut date leads to greater meadow species richness. A helping hand to the traditional grazing method is also useful as studies have shown that the addition of appropriate seed mixes helps establish good species richness.
The course involved a number of case studies/site visits looking at grazing and non grazing on a variety of different upland habitats. Sites included Newborough Warren Site of Special Scientific Interest (SSSI) and Llanddwyn Island, both on Anglesey, to study grazing management in action using ponies and cattle on coastal habitats; Caeau Tan y Bwlch, managed through a partnership between Plantlife, The Wildlife Trusts and Natural Resources Wales; and Cwm Idwal National Nature Reserve. This Nature Reserve with its mountain habitats had previously been heavily grazed, but grazing had been removed in 1998 to help restore priority features, including rare plants. The image here shows an exclosure (on the right) that has been closed off from grazing for approx. 40 years, showing how vegetation varies from that on the left, which has been excluded from grazing for only approx. 10 years. It was surprising to see that the majority of vegetation in the 40-year exclusion area was still barely knee-high. On this particular site, without grazing, there is currently a diverse botanical richness of species and structure, and it hasn’t become swamped with invasive species or scrub. This is an improvement in terms of biodiversity against the original uniform short sward that once covered the area, caused by over-grazing.
When looking to choose the best grazing animal for an area we learnt that:
- Sheep can select particular plants and leaves down to ground level. Horses can also select to plant level.
- Cattle have a big, wide mouth, and eat by wrapping their tongue around vegetation then pulling it out. They can only graze down to about 5cm from the ground, and can eat a variety of plant species in one mouthful. As they take longer to digest their food, they are able to absorb more nutrients from poorer grasslands.
- Mixing different types of grazing animals on a site can be very beneficial, e.g. on grassland dominated by Molina (Purple Moor Grass), grazing with sheep only saw increased spread of Molina, but with a ratio of 1.5 ewes to 0.75 cattle grazing the area, there was a significant decrease in Molina.
- Some grazing animal breeds do better than others in the winter (usually native breeds over continental breeds).
- Grazing animals change their plant preferences depending on their nutritional needs, and tend to choose the tastiest and most nutritional plants first. They can also change their preference for different plants throughout the year.
- Where animals have had particular worming treatments it is necessary to make sure the treatments have had time to flush through (at least 3 weeks) before the animals enter a conservation grazing area, to avoid detrimentally affecting beneficial and non-target invertebrates at the conservation site.
It is important to consider whether, on a conservation grazing site, the animals are going to be:
- Living a natural life? e.g. in an environment to which the species/breed is adapted;
- Fit and healthy? e.g. able to achieve normal growth and function, and maintain good health in adult life;
- Happy? e.g. sense of mental satisfaction, or at least freedom from mental distress.
The Grazing Animals Project has helpful advice.
Welfare of Farmed Animals (England) regulations (2000, 2003): includes duty of care by both Owners and Keepers. Persons attending to the animals should be acquainted with the relevant statutory welfare codes. So for conservation grazing management we need to
- Enlist the help of an expert on that species/breed.
- Ensure a site risk assessment for the grazing animals is carried out well in advance of putting the animals on the site, keep the document under review.
- Ensure there is adequate contingency planning, in case the usual stock keeper/checker is unable to tend to the animals for any reason.
- Make sure we’re not accidentally breaking the latest animal movement and standstill regulations and transport welfare regulations.
Every plan needs a sustainable goal – and we need to know when we’ve reached that goal.
Currently lapwing are in the spotlight as they are declining in the UK, however their initial population rise was due to post-war human habitat intervention, creating lots of grazed habitat that benefited them and other farmland waders over other species. What is our goal? – should we be concentrating our efforts on supporting lapwing? should we look to the species assemblages that were present prior to this? or should we work towards habitat mosaics supporting lapwing and the other species?
The rule of thumb is to start by grazing the area lightly. Establishing the level of grazing appropriate is always important, over or under grazing can be damaging or ineffectual. Incorporate regular assessment and survey. Monitoring the site is vital so that the effects of the grazing on the valuable features can be assessed, and the grazing adjusted if necessary. Be prepared to be flexible and ready to tweak if necessary – increase/decrease, change animals/timing etc. Be ready with Plan B if Plan A doesn’t work! Management plans need to be dynamic documents and be reviewed/amended/built upon as required.
Conservation grazing is not an exact science so this course was really valuable in learning from the experts and hearing about their experiences and the general principles they have adopted. As each site is so unique it is important to recognise our starting point and decide what we want our end point to be: we may currently have quite a species-poor grassland but we would like it to become a species-rich hay meadow….so then we can work up a management plan to make that happen.
Now to translate all we have learned to help manage relevant sites in the North York Moors National Park, through our Habitat Connectivity project!