https://defrafarming.blog.gov.uk/manage-scrub-and-scrub-mosaics/
Manage scrub and scrub mosaics
The guidance on this page is for SFI pilot participants only. Please visit GOV.UK for the official Sustainable Farming Incentive scheme guidance.
Find out how land managers can maintain scrub and scrub mosaics to provide food and shelter for wildlife.
If you’re completing this action as part of the Sustainable Farming Incentive pilot, how you do it is up to you.
The advice on this page can help you get better environmental and business benefits, but you do not have to follow it to get paid.
About scrub and scrub mosaics
Scrub includes all growth stages of native shrubs, from scattered bushes to closed canopy vegetation. Good scrub has a diverse structure with different heights, though it’s usually less than 5 metres tall.
When patches of scrub grow in habitats like grassland, it’s described as a mosaic.
Scrub provides wildlife with food and shelter and has the greatest benefit where:
- there are a variety of native species of shrubs like hawthorn, blackthorn and hazel
- it has a range of heights, ages and structures
- it grows in a mosaic with tall grass or other vegetation and flowering herbs, like thistles, ragwort, hogweed and black knapweed
- it has edges that flow naturally into surrounding vegetation
- scrub and mosaic vegetation, like grasses and herbs, flower and set seed to produce new habitat
- occasional open grown trees develop through thorny scrub and bramble
- shrubs develop standing or fallen dead wood
You can develop more complex scrub mosaics on larger areas, to provide different environments for more species. Even small areas of scrub scattered across a landscape provide resources for wildlife.
Where to maintain scrub and scrub mosaics
Scrub and scrub mosaics are valuable in areas dominated by arable land and agriculturally improved grassland, where food and shelter for wildlife are in short supply.
Keep and maintain scrub in unmanaged areas:
- on field corners
- alongside woodland edges or hedgerows
- on land which is difficult to graze
- next to water bodies and watercourses, as a buffer
Aim for scrub and scrub mosaics across 2% to 10% of the farmed landscape. If it’s less than this, you could create scrub and scrub mosaics.
Benefits of maintaining scrub and scrub mosaics
When you maintain structurally diverse scrub, or scrub as a mosaic with other vegetation, you’ll:
- have a habitat rich in invertebrates, reptiles, amphibians, small mammals and birds
- create habitat that supports natural predators of crop pests and diseases
- provide forage for livestock later into the year than other grazing habitat, like grassland
- buffer other habitats like water bodies, farm woods and priority habitats
- boost populations of pollinators
- support lichen communities, which provide food and nest material for wildlife
- help remove carbon from the atmosphere
- maintain carbon-rich soils
How to maintain scrub and scrub mosaics
Scrub and scrub mosaics need little management, apart from some grazing and browsing by livestock and wildlife. Manage scrub where it becomes too dense. Aim to keep a diverse structure with varied heights and species, to maintain its value to wildlife.
Do this by:
- allowing new areas of young scrub to grow
- increasing areas of open space within larger patches of scrub
The best way to maintain diverse scrub is with light browsing and grazing by livestock and wildlife. Cattle can graze and trample scrub to create open patches. Low levels of deer browsing will also maintain diverse scrub.
You can cut scrub if livestock are not available, or if the livestock will not graze scrub or scrub mosaics.
Before you start
If your land is part of a Site of Special Scientific Interest (SSSI), you must check if you need consent to retain or graze scrub.
Birds, nests and eggs are protected by law. You must check the area before cutting. If you see signs of nesting birds, delay work until birds fledge.
Avoid activities which disturb or damage breeding and resting places of protected species, unless you have a licence. These include dormice, bats, amphibians and reptiles.
Grazing and browsing
Livestock and wildlife will help create:
- scrub with diverse structure
- a range of native scrub species growing
- areas of open ground with tall grasses and flowers growing in-between
Use cattle to manage scrub where possible. Most breeds do not browse but they can:
- open paths through scrub by trampling
- create patches of bare ground, which is important for basking reptiles, invertebrates and for wildflower germination
You can use other livestock or wildlife to keep a diverse structure, but you should closely monitor them. Sheep or high levels of deer browsing can damage scrub and cause a decline in scrub species. You can fence areas to exclude deer.
With all livestock, start with low numbers. You can increase it until you get the right balance. Alternatively, you can choose to graze over a shorter period.
Avoid grazing scrub too heavily for long periods.
Do not place supplementary feed in scrub or scrub mosaics. This can reduce many of the benefits, cause poaching and nutrient enrichment, and damage soil structure.
Cutting scrub
Leave patches of scrub uncut to protect mature scrub and keep dead wood. These undisturbed areas:
- provide shelter and hibernation sites for invertebrates and amphibians over winter
- support lichen communities and fungi
Retain areas where trees that develop through the canopy (open grown) are protected by thorny scrub.
You may need to cut scrub in some areas to:
- maintain variation in height and structure
- maintain open areas within a scrub mosaic to support important plant and animal species
- create some areas of young regrowth by coppicing
- protect sensitive historic or geodiversity features from damage
- maintain the condition of species-rich grassland
- remove scrub where it spreads onto grassland that has wading birds, like lapwing or curlew
- stop it from shading lichen communities, as they need well-lit areas to grow
You can cut scrub using hand tools like:
- bow saws
- mattocks
- chainsaws
- brush cutters
You can also use tractor-mounted flails.
If you’re cutting to encourage regrowth you can cut shrub species to the ground. Cut or coppice areas of scrub in rotation, aiming to keep all age ranges. Then leave regrowth and:
- cut again in rotation
- manage using machinery
- browse with livestock
Coppice small patches or areas at a time. Avoid cutting patches that are next to each other in subsequent years, because it reduces the foliage available for invertebrates to feed on. Do not cut shrubs with berries until after Christmas because birds and mammals eat them.
Talk to the Forestry Commission to check if you need a felling licence to remove trees and tall scrub.
Managing scrub edges
Scrub edges should have tall vegetation gradually reducing in height to match the surrounding field.
Avoid topping dense patches of scrub. Some taller trees above dense scrub help build an open grown canopy.
You can use a flail mower on scrub edges to maintain open areas within scrub, where grazing is not possible.
Mow once a year in late summer or autumn, to avoid destroying seeding herbs. This will keep grassy scrub edges open and encourage flowering herbs.
Where adders and other reptiles use scrub edges for basking, you can either:
- mow edges in winter when they are hibernating
- use hand tools to cut back scrub
What to avoid when managing scrub
Burning scrub
Do not burn scrub or scrub mosaics because this can:
- destroy habitats and have catastrophic impacts on wildlife
- reduce the structure and diversity of scrub species
- prevent the growth of trees
- limit the development of dead wood
- reduce air quality
Cultivation
Avoid ploughing, reseeding and cultivation because it prevents habitats developing naturally.
Fertilisers and manure
Do not apply fertilisers or manure, as increased nutrients can stop a wider range of species from growing.
Herbicides and pesticides
Do not apply herbicides or pesticides. They will damage plant fungi and invertebrates living in scrub and scrub mosaics.
What successful scrub and scrub mosaics look like
There should be diverse scrub over 2% to 10% of the farmed landscape, as either:
- scattered patches throughout the landscape
- part of a larger mosaic with tall grass or other habitat
You’ll see:
- at least 3 native species of shrub established with different heights, ages and spacings
- tall grasses and flowering plants growing in open areas between scrub edges
- patches of mature scrub protecting occasional growth of open grown, tall trees
- scattered clumps and edges that grade into surrounding vegetation
- basking reptiles and invertebrates in open areas between scrub
- caterpillars of moths like orchard ermine, pear leaf blister and light emerald feeding on hawthorn trees
- farmyard birds such as turtle dove, yellowhammer and corn bunting
