Hull Biodiversity Action Plan

Trees are found in many situations within the urban environment. This action plan covers woodlands, parkland, wood pasture and individual trees in streets and gardens. Deadwood habitats, hedgerows, scrub and areas of natural regeneration are also included. Trees play a vital role in the urban ecosystem, providing local benefits for wildlife. Many birds, mammals and invertebrates use trees as roosts, breeding sites and feeding areas.

Woodland

Woodland can be defined as vegetation dominated by trees more than five metres high when mature, forming a distinct though sometimes open canopy. Existing woodland, new plantations and commercial plantations are all included in the plan.

Tree stump

Parkland and Woodpasture

Parkland and woodpasture are the products of historic land management. They usually consist of large, open grown or high forest trees (often pollards) at various densities. Most of the trees are usually native, but there may be non-native species, which have been planted or have grown naturally.

Roadside Trees

Trees and shrubs, in streets, recreation areas or private gardens play an important part in making our urban area a more pleasant place to live. They perform a number of functions: reducing air and noise pollution, creating shade, softening the built environment and creating local distinctiveness. In urban areas, with few wooded habitats, roadside trees are especially important for wildlife.

Deadwood

Deadwood is valuable for wildlife, providing a range of habitats including dead limbs on living trees, decay columns in trunks and branches, rot holes in standing trees and standing and fallen deadwood. Deadwood habitats become available as homes for a variety of invasive organisms such as bacteria, lichens and fungi. These organisms make the habitat more easily accessible for other animals for breeding or shelter. All trees, including ornamental trees, are potential sources of deadwood, whether they are in woodlands, or as single specimens in parks, gardens, hedgerows, or avenues in towns and cities.

Scrub

Scrub can be defined as vegetation made up of either native or non-native shrubs and tree saplings ranging from scattered bushes to closed canopy vegetation, usually less than five metres tall, occasionally with a few scattered trees. Scrub is often a stage in the natural succession to woodland. The value of scrub for wildlife depends on the species present and their age range, therefore it varies over time.

Hedgerows

Hedgerows resemble woodland edge and scrub habitats; they are important habitats for butterflies and moths, farmland birds, bats and other mammals. Hedgerows may also act as wildlife corridors for many species, including reptiles and amphibians, allowing their spread and movement between other habitats.

CURRENT STATUS

The total area of woodland of 0.1 hectares and over in England is 1,097,000 hectares, representing 8.4% of the land area. Fifty-four percent of all woodland is broadleaved. Conifer woodland represents 26%, mixed woodland 12% and open space within woodland 6%. There was a significant increase in woodland cover during the second half of the twentieth century. It is estimated that there is about 450,000 km of hedgerow in the UK.

A recent 10-year survey by the Forestry Commission has shown that Hull and Humberside have the lowest tree cover in England. Since 1991 the cover has increased in other parts of Yorkshire but the East Riding area has stayed static and therefore fallen behind.

Within Hull there are examples of several wooded habitats. However all examples are small and none of them is completely natural. Most of the patches of mature trees are very open with little under-storey and therefore not attractive to all woodland species.

There are several woodlands in Hull. Ings Plantation at Kingswood, which is made up of a mixture of Ash (Fraxinus spp.) and oak (Quercus spp.), and Ash Plantation at Bransholme are particularly important to the City's wildlife. Birch Plantation in Priory Yard East is made up of Birch (Betula spp.) and Willow (Salix spp.) and is one of the few naturally regenerated woodlands in the City. Disused railway sidings provide excellent examples of scrub habitats within Hull. 'The Lozenge' is a particularly good example of this. Tree-lined areas such as the Avenues, Newland Park and Salthouse Road provide a substantial number of mature trees and shrubs. Mature ash, oak and beech provide roosting holes for bat species, especially the highly tree hole dependent Noctule bat (Nyctalus noctula).

The City Ecological Survey in 1992 included 28 km of hedgerow, of which 95% were unmanaged and may therefore have deteriorated as both wildlife habitat and landscape features.

CURRENT FACTORS AFFECTING THE HABITAT

Urban expectations of tidiness (e.g. mowing, removal of fallen leaves and dead wood) often reduce the natural biodiversity.

There are often conflicting pressures for land use, for example development, and consequent loss of habitat.

Dutch Elm disease had significant adverse effect on the Elm population in Hull. Many of the avenues of Hull were once lined with Elms, nearly all of which have been lost.

Vandalism is a constant issue in urban woodlands, usually through firestarting; the uprooting of newly planted trees, dumping and litter accumulation.

Isolation and fragmentation of woodlands has resulted in poor dispersal of dependent species.

Invasion of non-native species such as Rhododendron, Giant Hogweed, Japanese Knotweed and to a lesser extent Sycamore have reduced the diversity of many woodlands.

Woodlands may be perceived as threatening places and may give cover for antisocial behaviour and crime.

In some woodland there is a lack of younger generations of trees producing a skewed age structure.

Neglect and loss of expertise of traditional tree management techniques (e.g. pollarding), leading to trees collapsing or being felled for safety reasons.

There are conflicts between roadside trees and the foundations of older houses; this problem is especially prevalent in Hull because of the high clay content of the soil. There is pressure to lop or remove trees to avoid or reduce structural subsidence. This leads to a significant level of damage to the urban tree stock.

Damage to roadside tree roots from soil compaction and erosion can be caused by people walking and car parking.

The digging of trenches close to trees can cause root damage and reduce their safe useful life expectancy, leading to their early removal. Principal causes of this type of root damage occur during the installation and maintenance of cable TV, IT networks and of statutory services (e.g. water, gas, electricity and sewerage). The construction and improvement of highways can also be locally significant.

If scrub is left unmanaged it will eventually turn into woodland and the important habitat that scrub provides will be lost.

Neglect or poor management of hedgerows, (no cutting or laying) leads to them changing into lines of trees and the development of gaps.

CURRENT ACTION

Legal Status

There is a wide range of statutory acts (namely the Town and Country Planning Act (1990) and Wildlife and Countryside Act (1981)) and local by-laws that impose a duty on local authorities and the general public to protect certain trees, habitats and the species that use them. These are supported by guidance from government, government agencies and non-government organisations in the form of circulars, advisory and practice notes.

Management, Research and Guidance

The UK Biodiversity Steering Group has published a Habitat Action Plan for Lowland wood-pasture and parkland. The objectives and targets for this habitat cover conservation, restoration and expansion. The national target is to protect and maintain the current extent and distribution of lowland wood-pasture and parkland in favourable ecological condition.

There is a wealth of management advice available with some opportunities for grant aid. The Forestry Commission administers the Woodland Grant Scheme (WGS), which provides grants for planting trees and managing woodlands. They also publish a large range of free and priced literature, from basic information leaflets to detailed technical handbooks, on forestry subjects. The Forestry Commission's 'National Inventory of Woodland and Trees in England' was completed in 2000. The inventory provides information on the extent, distribution and composition of woodland in the whole of the country.

National Tree Week is organised annually, usually in November/December, by the Tree Council to celebrate the start of the tree planting season, and to raise awareness of the importance of trees and their good management.

British Lichenological Society has produced a habitat management guide for lichens, including wood-pastures and parkland.

KuHCC Urban Forestry Department maintains trees within Hull where necessary, and carries out new planting schemes. They are also responsible for emergency tree works i.e. storm and gale damage. KuHCC Grounds Maintenance are responsible for maintaining hedges within the City. Privet hedges within our parks are cut three times per year, as are hedges belonging to selected council houses. General Privet hedges are cut twice a year and Thorn/Beech hedge is cut once per year.

ACTION PLAN AIMS

To protect and maintain the current extent and distribution of trees, scrub and hedgerows within the City.

To make greater use of native species where appropriate.

To encourage planting of native trees and shrubs, especially those of local provenance.

To ensure that scrub habitats are well-represented across Hull and within a range of habitats, and prevent loss of scrub habitats that support sensitive species or suites of species, particularly where scrub forms a mosaic with other habitats.

To increase the amount of deadwood within the City.

To improve hedgerow management.

To monitor the bird species in trees, scrub and hedgerows.

To increase public awareness of trees and tree planting within the City.

WHAT WE ARE GOING TO DO

Action	Target	Partner	Aim
Policy and Legislation
No policy or legislation proposed.
Habitat Management and Protection
Increase the amount of deadwood habitat.	Ongoing: Where possible allow trees and parts of trees to mature, die, fall and decay naturally without interference. Ongoing: Crowns of trees only removed where necessary.	KuHCC (Parks and Open Spaces)	5
Ensure that scrub is well-represented across Hull and within a range of habitats.	Ongoing: Identify important scrub areas and carry out management to stop valuable scrub habitats turning to woodland.	KuHCC (Parks and Open Spaces)	1,3
Plant hedges in suitable habitats.	Ongoing: Planting of hedgerows around parks, golf courses and cemeteries where appropriate.	KuHCC (Parks and Open Spaces)	1,2,3
Improve hedgerow management	Ongoing: Manage hedges on a rotational basis so that each is cut only once every 3 years.	KuHCC (Grounds Maintenance)	6
Encourage use of local provenance trees.	Medium Term: Establish nursery for local provenance trees.	BGEEP, YWT	2,3
Improve understorey.	Medium Term: Understorey improvements to existing woodland areas through introducing suitable native species.	KuHCC (Parks and Open Spaces)	3
Improve links between woodland sites.	Ongoing: Plan plantings to create links across the City.	KuHCC (Parks and Open Spaces, Highways, Planning)	3
Advisory
Promote planting of native trees and shrubs.	Short Term: Promote planting of Buckthorn to provide larval food source for Brimstone Butterfly. Medium Term: Produce information leaflet for garden centres on native trees and shrubs people should plant in their gardens for wildlife.	YBC KuHCC (LA21, Planning), University of Hull, YWT.	2,3
Future Research and Monitoring
Monitor birds in trees, scrub and hedgerows.	Ongoing: Monitor bird species.	HVWG, EYB	7
Communications and Publicity
Education and promotion of 'A Greener City'.	Short Term: Events, public consultation, flagship projects and publicity.	KuHCC (All), YWT	8
Increase awareness of 'Trees for Babies' scheme.	Ongoing: Promote 'Trees for Babies' scheme.	KuHCC (Parks and Open Spaces, Registry Office)	8

WHAT WE CAN ALL DO

Plant native trees and shrubs, preferably using plants of local origin.

Leave deadwood to decay naturally.

Carry out hedge maintenance in late winter (December-February) so that nesting birds are not disturbed and flowers and fruit are produced.

LINKS WITH OTHER ACTION PLANS

This Habitat Action Plan should be considered with those for Gardens and Allotments, and Parks, Golf Courses and Cemeteries. Elms were once common on the tree-lined avenues of Hull but are now very rare in the City. Lichens occur on many trees. Open woodland is the preferred habitat of the Spotted Flycatcher. Woodland edge and hedgerows are important habitats for the Tree Sparrow, Hedgehog, Common Lizard, Great Crested Newt and Common Toad. Reed Buntings also often use hedgerows in the winter. Buckthorn growing in hedgerows is essential for the survival of the Brimstone Butterfly. Scrub habitat is particularly important for the Linnet.

REFERENCES

Carr, S., Nell, M. (1991) Practical Conservation. Boundary Habitats. Open University and Nature Conservancy Council, Hodder & Stoughton, London.

Fuller, R.J., Peterken, G.F. (1995) Woodland and Scrub. In: Managing Habitats for Conservation, ed. Sutherland, W.J. & Hill, D.A. 327-361. Cambridge University Press, Cambridge.

Hodge, S. J. (1995) Forestry Commission Handbook 11: Creating and Managing Woodlands around Towns. HMSO, London.

Kirby, K.J., Drake, C.M. (1993) Dead Wood Matters: The Ecology and Conservation of Saproxylic Invertebrates in Britain. English Nature Science 7. English Nature, Peterborough.

UK Biodiversity Steering Group (1995) Biodiversity: The Steering Group Report. Volume 2: Action Plans. HMSO, London.