Why survey hedges?
a comprehensive review of ‘Good practice for hedgerow management’ By Susan Stangroom Biodiversity Officer, North Somerset Council
- Hedges are important wildlife refuges and corridors. Those of value for wildlife need to be identified to encourage biodiversity.
- With climate change causing variations in wildlife populations, it is important to have a ‘baseline’against which these variations can be measured.
- Hedges make a significant contribution to the landscape character of the English countryside.
- Locations of veteran trees need to be established.
- Historical hedges have archaeological value.
Many hedges were established during the enclosure acts, 1750 – 1850. The landowners appointed commissioners who sometimes partitioned the land unfairly.
In England and Wales there were about –
- 800,000 km of hedges in 1947
- 600,000 km of hedges in 1984
- 400,000 km of hedges in 1993
Recording information on hedges
- We must have permission from the landowner
- We have to work to a set of rules laid down by DEFRA.
- We record as many of the species as we can identify.
- We send a copy of the survey to the Bristol Regional
Environmental Records Centre and to the landowner
The Hedgerow Regulations were made under the Environment Act 1995 and introduced into England and Wales in 1997 in order to protect hedgerows as a characteristic feature of our countryside.
It is now against the law to remove most countryside hedges without permission. A person removing a hedgerow without permission may face an unlimited fine. and the person will probably be asked to replace the hedge.
Unfortunately the Act is quite weak, and less than 20% of hedges qualify for protection. Many important wildlife-rich hedges are still being lost.
In the UK, hedges occupy a larger area than all nature reserves combined. Hedges provide food and protection for many animals – for instance berries and nesting sites for birds.
To have a complete history of some hedges it is necessary to consult old maps. Interpretation of hedge lines can tell us much about local history.
Max Hooper studied 227 hedges from 75 to 1,100 years old. He found that the number of tree and shrub species in a 30 metre length of hedge is roughly equal to the age of the hedge in centuries. This may be either because the hedge acquires more species with age, or because early hedges were planted with a greater variety of species.
In order to qualify for protection, a hedge must be at least 30 years old, and protection is rarely given to urban hedges.
The degree of protection is dependent on:
- or the number of ‘woody’ species in a 30 metre length (a minimum of six species per 30m)
- or the presence of rare species
Hedges provide natural corridors for the spread of species. Hedges are very beneficial for bats, and most British species of bat are endangered. In this area, Horseshoe Bats are particularly important since the South West is their last remaining stronghold.
Yansec has donated very sophisticated bat detectors and associated computer software for the analysis of the bat calls. This has enabled the North Somerset Wildlife Wardens to identify the species of bat using these hedges with greater certainty. A survey of the use by bats of local hedgerows is planned for the coming season.
The North Somerset Wildlife Wardens working with North Somerset Council have a programme for surveying the status and biodiversity of hedges in this area.
Would you like to help us with this work? If so you should contact me, Terry Smith