Lowland Wood Pastures & Parkland
The Barn Owl
Barbastelle
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Lowland Wood Pastures & Parkland |
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The Barn Owl |
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Barbastelle |
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Oak Polypore |
Think of a medieval deer park with mature oaks growing widely spaced over rolling grassland, or the rather similar appearance of ancient “trees with pasture”, where oaks were pollarded for wood at a height above the reach of the grazing cattle. A number of such sites exist in Suffolk, some of them scarcely altered over the centuries. Staverton Park/Staverton Thicks, a site of Special Scientific Interest, and Aspal Close, now a Local Nature Reserve, are good examples of the sort of biotope that is encompassed by this Habitat Action Plan. Neither is a natural habitat, as both have been created and maintained by man, yet there has been such continuity of management that particular categories of wildlife have been able to endure, whilst the surrounding countryside has changed around them. In particular, the veteran trees are a special feature, and the communities of flies and beetles that live in deadwood are found to flourish on such trees. Grand parks grew up around grand country houses, and many can still be found in our countryside, yet the character of many has changed with the cessation of grazing, or a conversion to arable farming during World War 2. Most have not been properly surveyed for invertebrates, but some of those that have repaid the effort with unexpected diversity or scarce species. The habitat plan lists no less than 24 ways in which such sites have lost their character, and proposes steps by which further loss may be prevented. Veteran trees support a wide range of invertebrates, but also provide nesting, places for bats and some bird species that appreciate continuity. Living, dead and dying parts of old trees each host different fungi, whilst epiphytes and bryophytes make up a community of dependant growths. An extreme example for rarity is the Oak polypore, a fungus known only from a single dead oak tree in Staverton Park!, The Barbastelle bat is not associated particularly with parkland, but it hibernates in trees, and undisturbed veteran trees provide some of nature’s best hibernation sites. The grassland below the trees is home to good populations of moths and butterflies as well as small mammals, including the Short-tailed vole, the main prey of the Barn Owl, a bird that will hunt over parkland, sometimes using the outbuildings of the stately home to nest. The Barn owl is one of Suffolk’s “character species”, and its action plan follows, along with the Barbastelle and the Oak polypore.
1 Definition
In Suffolk there are both the remnants and the active practice of a tradition of using the same land to grow trees and graze animals. Today this land is defined as wood-pasture (Silva pastillis). In many cases today’s parklands have evolved through a complex series of changes starting with the medieval deer park. Consequently much of the parkland we see today is quite different to its medieval origins. New species of trees and shrubs have been introduced into this country and there have been fashions for designed landscapes. This rich variety of historic landscapes has created a wealth of habitats and niches for wildlife. Low woodland-pasture and parkland habitats may be identified as containing a range of National Vegetation Classification (NVC), stand types. In Suffolk, the following are likely to occur .
Quercus robur ~ Pteridium aquilinum
~ Rubus fruiticosus woodland (W10)
Quercus robur ~ Betula spp. ~
Deschampsia jlexuosa woodland (W16)
Fraxinus excelsior ~ Acer camprestre
~ Mercuralis woodland (W8)
It should be recognised that lowland wood pasture and parkland are habitats in their own right This ecosystem is likely to be of interest for, invertebrates (especially the saproxylis), epiphytes, bryophytes. fungi, bats and woodland birds.
2 Current status
2.1 National
There are no reliable statistics either nationally or for Suffolk, nor has the current rates of degradation or loss of this type of habitat been surveyed accurately. National figures of 10- 20,000 ha “currently in working condition” was given in the UK This habitat is better represented in lowland Great Britain than elsewhere in Europe, although scattered examples are to be found throughout the Europe. Parklands may be a seed pool for distinctive local phenotype. These areas are of outstanding European importance. Wood pasture is known to be of primary importance to eight national priority species that occur in Suffolk and for a number of saproxylic Coleoptera (deadwood beetles)and Diptera (Flies).
2.2 Local
Suffolk has a rich heritage of wood pasture and parkland.
Early maps and, documents describe the county as having vast numbers of free
standing trees in pastures and parks.
Surveys at Denham (1651) and Thorndon (1742) record densities of 15.4 and 29
trees per acre respectively, an extraordinarily high figure compared to today. This
habitat type has been poorly recorded in Suffolk with parkland often being
tagged onto woodland or grazing land surveys, as a result parkland estimates
for Suffolk now vary between 620 ha and 1,102 ha. The Historic Parks and
Gardens Survey (Suffolk County Council) for, Suffolk does not assess habitat
value or sustainability of this habitat type. Research by Leicester University
into DNA of ancient trees has made it possible to identify the likely geographical
origin of Britain’s oak trees. As a result of genetic mutation and the different post-glacial colonisation of Britain and Europe the oaks of East Anglia were found to be a unique variant, raising important bio-diversity implications.
Lowland wood-pasture and parkland are products of historic land management Typically they consist of large open-grown or high forest trees (often pollards) at various stocking densities in a matrix of grazed grassland, heathland and / or in woodland. Tree management has helped produce characteristic ancient trees, sometimes of great age. Often such trees are part of our cultural heritage, and they have been described as cultural icons in ever changing landscapes.
2.3 Natural Areas
The majority of medieval deer parks are usually on clay, with the post medieval deer parks being on the junctions of clay and sand. Soil types may have been a consideration, but the siting of parks was more complex than just juxtaposition of soils. Access to large houses and significant views may have been a deciding factor too. Parklands are more often found in the Suffolk Coasts & Heaths, the East Anglian Plain Natural Areas and within the Breckland area.
3 Current factors affecting the habitat in Suffolk
Wood-pasture and parkland in
the county is affected by numerous direct, or indirect factors. These include:
Bracken and other invasive species.
4 Current action
In Suffolk, some areas of Wood-Pasture and Parkland have been given statutory conservation status (See the English Heritage Register). Two sites have been designated Sites of Special Scientific Interest (SSSIs). One site has been designated an internationally important site (SAC) and others are protected by Tree Preservation Orders or are within Special Landscape Areas and/or Areas of Outstanding Natural Beauty. The Suffolk Wildlife Trust has identified County Wildlife Sites that have some protection through the local planning authorities development plans (Supplement on Planning Guidance, Suffolk Coastal District Council). Tree preservation orders and Conservation Area Status may also be responsible for the protection of some wood- pasture and parkland. Species such as bats and some birds which utilise ancient trees are fully protected under the Wildlife & Countryside Act 1981. This also gives some protection to their place of shelter.
5 Action plan objectives and targets
1 Improve knowledge of extent, distribution and quality of wood pasture, and Parkland in Suffolk.
2 Identify areas of wood-pasture and parkland that are under threat.
3 Maintain the existing extent of wood pasture and parkland.
4 Improve the targeting of grants to assist in the management of areas of, wood-pasture and parkland.
5 Initiate measures to better protect wood-pasture and parkland sites. Achieve favourable conservation condition over 70% of all parkland, sites and 50%of all lowland wood pasture sites by 2010. 6 Seek additions to the English Heritage register of Parks.
7 Maintain and strengthen populations of key BAP species associated with, wood-pasture and parkland through sound sustainable habitat, management.
8 Subject to owner agreement undertake condition surveys and, management proposals of all historic parklands in Suffolk. 50% by 2005, and 100% by 2010.
9 Help and encourage the preparation and adoption of historic landscape, management plans.
Barn owl (Tyto alba)
The Barn owl was a relatively common bird of lowland farmland, hunting at dusk over rough grassland. Rough grassland supports its main prey, the Short-tailed vole. The numbers of Barn owls have declined since the 19305, and the availability of suitable nest and roost sites are crucial to maintain the species successfully in an area. The Barn owl, with its evocative ghostly form, is an important flagship species for encouraging the maintenance and creation of rough grassland habitat.
1 Current status
1.1 National
Barn owls were once a common feature of farmland and other rough grazing but have suffered a severe decline since the 1930s, with the population estimated in the late 1980s at less than half of that recorded formerly. The species is included in the Red Data list as a species of special concern being ‘potentially at risk’. The 1988-91 Atlas of Breeding Birds indicated a decline of 37.5%, in Britain since the 1968-72 survey. However it recognises that the species is particularly difficult to survey and that its numbers show considerable annual variation, related to the three-year cycle of its main food supply, voles.
1.2 Local
The Suffolk Bird Report describes the Barn owl as a ‘fairly common resident’ . Pre the Second World War it was not uncommon on most Suffolk farms but its numbers fell dramatically from around 1945. In the mid 1970s it was recorded from about 40 parishes. The Suffolk Ornithologists’ (SOG) Raptor and Owl survey of 1995-1998 recorded it in 187 tetrads, including 50 reports of breeding. This, together with the records of the Suffolk Bird Report suggests that its numbers are not currently declining significantly within the county. The most striking feature of the recent records is the concentration of the species in the eastern part of Suffolk, most markedly in the coastal belt. Records indicate its absence from large areas of west and central Suffolk.
1.3 Natural areas
All.
1.4 Protection
The Barn owl is protected under Schedule 1 of the Wildlife and Countryside Act and the EC Birds Directive.
2 Current factors causing loss or decline
There are many factors implicated in the decline of the Barn owl.
Loss of feeding habitat. The Barn owl is dependent on rough grassland for its prey. The favoured prey, short-tailed vole. wood mouse and common shrew require rank or rough grassland with a thick sward and deep litter layer. Although large areas of such grassland, for example old parkland and coastal marshes, are valuable, it is the unmanaged grassland of field margins associated with open ditches and hedgerows that are particularly important. Such areas need periodic management to prevent scrub invasion.
Agricultural intensification
has reduced the extent and quality of prey-rich habitat. Within Suffolk 96% of
unimproved grassland has been lost since 1939. More intensive
management of field margins, watercourses, hedgerows. woodland edges and
roadside verges has also been a factor in reducing the availability of feeding habitat.
Improved methods of crop storage have reduced the availability of rats and mice, a winter food source.
Loss of nest and roost sites. Rural development, especially barn conversions, is seen as an important factor in the decline of the Barn owl. Regulations requiring the exclusion of birds from buildings used for the production of foodstuffs may also reduce the availability of nest and roost sites. Within farm buildings nests in bale stacks are most common and these may be vulnerable in Spring as the bales are removed.
Within Suffolk, where heavy rainfall is less of a threat to owlets than in other parts of the country, a larger proportion of Barn owl nests are recorded from hollow trees. Old, isolated trees in pastures, parkland or hedgerows and remote from disturbance are used, with the nest in the main trunk or near the crown of pollards. Oak, English elm, Ash and Willow are favoured. The loss of such trees through disease, old age or removal for economic or safety reasons limits the available nest sites.
There is concern nationally over owl poisoning resulting from owls eating rodents which have fed on pesticide sprayed cereals or second generation rodenticides (e.g. brodifacoum, flucomafen).
Construction of new roads and extra traffic has led to increased mortality of Barn owls, though local information is limited. Barn owls are attracted to roadside verges as they form rich hunting grounds; new road construction may also bisect traditional hunting areas increasing danger.
Continuity of feeding habitat, with linking corridors of suitable grassland, is important especially for post breeding dispersal. The intensive agricultural character of much of central and western Suffolk may limit the opportunities for the species to spread from its relative stronghold in the east.
3 Current action
BTO and Hawk and Owl Trust national survey.
Suffolk Ornithologists’ Raptor and Owl survey.
Continuing collation of records by SOG and SBRC.
Countryside Stewardship and ESAs provide opportunities for, promoting habitat creation and management of benefit to Barn owls.
4 Action plan objectives and targets
1 Stabilise the population and prevent further decline.
2 Maintain present breeding numbers in east Suffolk and reverse the, decline in numbers in west Suffolk.
3 Protect the Barn owl’s feeding habitat.
4 Safeguard the availability of nest sites and increase their availability, where appropriate.
Barbastelle bat (Barbastella barbastellus)
A medium sized bat, rarely and erratically recorded in UK. No breeding roosts had been recorded in Britain before 1995. There are now two known regular breeding sites. Most records relate to individuals found in hibernation. Recorded in a wide variety of sites including house lofts, barns, trees and tunnels.
1 Current status
1.1 National
A rare bat but widely distributed. Only two known breeding colonies. UK population size unknown.
1.2 Local
Less than six individuals recorded in the county annually. Records are widely distributed but few regular sites.
1.3 Natural Areas
All.
1.4 Protection
Protected by the Wildlife and Countryside Act 1981, the EC Habitats and Species Directive Annex 2, under the Conservation Regulations 1994, the Convention of the Conservation of Migratory Species of Wild Animals (Bonn 1980) and the Agreement on the Conservation of Bats in Europe (London 1991). Local impact can be limited by activities in accordance with PPG9 (Planning Policy Guidance in Nature Conservation 1994).
2 Current factors causing loss or decline
Reduction in insect prey abundance due to intensive farming practices and
Loss of wetlands, hedges and other suitable prey habitats.
Loss and disturbance of hibernation sites in buildings. underground tunnels, structures and trees.
Disturbance and destruction of maternity roosts due to toxic, chemicals used in timber treatment and building works.
Loss of linear landscape elements (flight line features) such as tree lines and hedgerows.
3 Current action
All known roosts are listed in the County Wildlife Sites Register which is updated annually and supplied to all local authorities.
English Nature have engaged the Suffolk Bat Group to undertake all practical work associated with bat conservation to enable EN to provide statutory advice to householders, developers, timber treatment companies etc.
The Suffolk Bat Group advises and deals with over 100 English Nature enquiries a year, additional public enquiries and 12-15 talks and walks per year.
4 Action plan objectives and targets
1 Monitor existing known recorded sites.
2 Survey suitable potential breeding sites close to known areas.
Oak polypore (Buglossoporus pulvinus)
In Suffolk this rare fungus is has been found in Staverton Park and The Thicks and one other site near Sudbourne. Its fruit bodies appear during the summer, but do not persist long making monitoring the species difficult. It is a heartwood rotting species that requires exposed, seasoned wood of mature or dead oak trees. It is restricted to wood pasture habitat due to the need for a long continuity of mature oak.
1 Current Status
1.1 National
This species distribution is centred in Berkshire with a few outlying sites in southern and northern England. There is no evidence for an historic decline in England although it has become extinct through most of its European range, with recent records only from Latvia. It has been reported as far east as Japan. England is therefore the global stronghold of this species.
1.2 Local
Oak Polypore was first found at Staverton Park on a hollow dead oak during a field meeting of the British Mycological Society in 1985. It was found more recently by Ted Green in 1994 whilst ancient trees were being tagged. Survey work during 2001 has revealed the presence of more fruit-bodies on other trees in the Thicks and at another wood in East Suffolk. The possibility of bracken fires is considered to be a possible threat at Staverton. Collection of the fungus for the pot or for identification is not considered a threat as the site has no public access away from footpaths.
1.3 Natural Areas
Suffolk Coast and Heaths.
1.4 Protection
Oak polypore is classified as Endangered in Britain and is specially, protected under Schedule 8 of the Wildlife and Countryside Act 1981.
2 Current factors causing loss or decline
Lack of younger generation of host trees to ensure continuity of oak polypore habitat is a threat to the long term survival of the species.
3 Current action
Survey work during 2001 discovered new populations of the species at the Thicks and Captains Wood. Work is ongoing nationally to investigate, ways of propagating the fungus
4 Action plan objectives and targets
1 Establish current status and distribution of the species at, Staverton and suitable habitat in the vicinity,
2 Maintain and where appropriate enhance population of this species at Staverton Staverton Park and Thicks.
3 Consider use of material from Suffolk population for ex-situ cultivation and artificial establishment of this species at locations locally and nationally by 2010.
4 Seek information on the ecological needs of this species and apply new knowledge to Suffolk site.
© 2003 Suffolk Naturalists' Society