WOOD PASTURE & PARKLAND

 

 

Final draft April 2002

A Habitat Action Plan for Surrey


 

Introduction

 

“It is possible that our heritage of old trees, especially thousand-year-old oaks is the greatest biodiversity and cultural contribution we can make in Europe.  The UK may have the greatest remaining remnants of old growth pasture woodland.”

Butler, 2001.

 

 

Lowland wood pasture and parkland is identified as a UK ‘priority’ habitat (UK Biodiversity Steering Group, 1995).  This plan has been prepared as one of ten habitat action plans within the Surrey Biodiversity Action Plan and is designed to help implement national objectives and targets at the local level.  Due to the overlap between habitat and land-use types it will be necessary to refer to the other Surrey Habitat Action Plans.  In particular Lowland Unimproved Neutral and Acid Grassland and also: Lowland Heathland, Farmland, Open waters and Large Reedbeds, Wetlands and Woodland Habitat Action Plans (HAPs).  These habitats are parts of the mosaic of habitats that make up wood pasture and parkland.  However they will only be mentioned in this document as they are dealt with in detail in their respective HAPs.

 

The South East of England supports 70% of the UK’s wood pasture and parkland.  This is the highest proportion of any key habitat occurring in the South East.  In Surrey there are more historic parks and gardens than in any other part of Great Britain, with the exception of Greater London (The Future of Surrey’s Landscape and Woodlands, 1997).

 

 

1.     Habitat Definition

 

Lowland wood pastures and parks are habitats where there has been a tradition of grazing livestock amongst trees.  Typically wood pasture consists of trees, sometimes with scrub, in grazed grassland, heathland and/or woodland floral communities.  The trees are often large and open-grown (often pollarded) occurring at various densities and ages.  The canopy is at least partially open.  Definitions for grasslands, heathland and woodland habitats can be found in other Surrey Habitat Action Plans, along with details of their management needs.  Trees of great age are often a feature of this habitat.  Dead wood on the ground, or on mature, over-mature, ancient, dying or dead trees, provides an extremely important habitat for a rich association of species.  The following list gives features indicative of wood pasture.  The more features that are present the more likely a site is to be considered wood pasture and of good quality:

 

Old maps/records.

Oral evidence/tradition.

Historical/archaeological features typical of wood pastures.

Old, particularly ancient, trees are present.

Large herbivores present, particularly livestock.

A tree/woodland structure showing the impact of large herbivores.

A vegetation mosaic of open and wooded communities.

Often multiple generations of trees present.

(After an unpublished definition of wood pasture by English Nature).

 

Wood pastures and parkland can have very different historical origins, and thus have a range of appearances, for instance in tree density and distribution.  They can be formed from woodland that was grazed, but can also have originated from fields where most of the hedgerows were taken out leaving only the trees to grow on (common in parkland formed in the nineteenth century).

 

Relict wood pastures are those in which traditional management, particularly grazing, is no longer practised.  Parkland often has a similar structure to wood pasture, with open grown trees surrounded by open spaces.  Much parkland was managed as private wood pasture as were many royal woods.

 

Working wood pastures are those where an intact habitat is composed of free standing trees, scrub and grassland with tree management and the grazing of deer or livestock.  Some parklands retain ancient trees in modified grassland and scrub.

 

The UK HAP refers to the following as wood pasture and parkland components:

 

1.      Lowland wood pastures and parklands derived from medieval forests and emparkments, wooded commons, parks and pastures with trees in them.  Some have subsequently had a designed landscape superimposed in the 16th to 19th centuries.  A range of native species usually predominates amongst the old trees but there may be non-native species that have been planted or have regenerated naturally.

 

2.      Parklands with their origins in the 19th century or later that contain much older trees derived from an earlier landscape.

 

3.      Under-managed and unmanaged wood pastures with veteran trees, in a matrix of secondary woodland or scrub that has developed by regeneration and/or planting.

 

4.      Parkland or wood pasture that has been converted to other land uses such as arable fields, forestry and amenity land, but where surviving veteran trees are of nature conservation interest.  Some of the characteristic wood pasture and parkland species may have survived this change in state. 

 

And excludes:

1.      Parklands with 19th century origins or later with none of the above characteristics.

 

 

Biodiversity of Surrey Wood Pasture and Parkland

 

This habitat is important for various reasons.  It comprises structurally diverse woodlands with open habitats.  Old tree growth is especially important to the diversity and abundance of much of the associated wildlife. Lichens, invertebrates and fungi are particularly important species of this habitat.  They depend on old tree growth, which supports exceptionally rich communities.  Dead wood is a very important habitat for specialist invertebrates and fungi as well as their predators.  The mammal and breeding bird fauna found in wood pasture and parkland can be exceptionally rich where there is old growth.

 

Invisible biodiversity

Much of the important biodiversity dependent on this habitat is hidden in some way.  Very few fungi produce the obvious fruiting bodies we call mushrooms, most remain hidden in the soil or in trees both dead and alive.  Some species are microscopic.  Saproxylic invertebrate species remain hidden for much of their life cycle in the dead wood they shelter in and feed on.  Even bats can be very elusive as they have an ephemeral roosting pattern, tending to rotate their roosts.  Weather changes will stimulate them to change a roost site from one aspect on a tree to another (e.g. west-facing to east-facing).  Often a reported bat roost sighting cannot be verified as the bats have moved by the time a licensed bat worker arrives to check. 

 

Thus a problem with all “invisible biodiversity” is under-representation in records.  Species can only be recorded if they are seen or leave signs of their presence.

 

a)      Epiphytes

Epiphytes are plants growing on other plants, without being parasitic.  Various plants grow as epiphytes on trees; mosses, lichens and liverworts are important groups.  The common polypody fern, Poypodium vulgare, is an epiphytic vascular plant.

 

In lowland Britain areas of existing or former wood pasture, with ancient trees, have been found to support epiphytes and invertebrates which are absent or very little recorded in other habitat types (Harding & Rose, 1986).

 

Lichens

Lichen communities have declined drastically in recent years; the reasons for this can be seen by looking at some of the needs of species-rich lichen communities:

·        Communities take many years to colonise.  Those of dry craggy oak bark take over 400 years (Read, 1999).

·        Most lichens have poor dispersal ability and a distance of 2.5 km between suitable habitat spots can prevent colonisation / re-colonisation.

·        Many of the rare species are very slow growing.

·        Grazing alone may not provide enough light.  Human activity such as pollarding is important for increasing the available habitat, by allowing light in.

·        Lichens are very sensitive to air pollution.  Pollution favours the growth of a few (now common) species of lichen.  However most lichen species are intolerant of both air pollution and agricultural chemicals.  The air pollutants that are particularly bad for lichens are mostly in decline.  Thus the main pollution dangers for lichen at present are artificial fertilizers and slurry.  These cause high levels of nitrogenous products on trees.  This results in rapid algal growth, which overgrows lichens, preventing adequate photosynthesis.

·        Mature and ancient oaks support the richest communities.

 

Lichens depend on mature and ancient trees, with no ivy and with enough light.  Different species will colonise different parts of a tree, e.g. rain tracks, sheltered cracks, large horizontal branches and exposed heart-wood.  In parkland, some exotic trees can be important for lichen, e.g. Norway maple, walnut and tulip trees.  The Norway maple in particular provides an alternative habitat for species that would formerly have grown on elms (Read, 1999).

 

As Surrey has some very important wood pasture and parkland, with many ancient trees, it also has some interesting lichens.  Albury Park is one of the best sites for lichens in Surrey.  Here the lichen, Thelopsis rubella, grows in rain tracks and shallow crevices.  It is a rough bark species indicative of ancient woodland and usually found on oaks and is rare in Surrey and extremely rare nationally.  Three species of Calicium grow on the mature and ancient oaks; Surrey is one of the few places in which all three species occur.  Calicium gaucellum and C. salicinum are extremely rare elsewhere in England, being found mostly in western and northern Britain.  C. viride is more common.  The Calicium spp. grow in sheltered sites on exposed standing dead-wood.  Such lichens are part of the relic colonies of ancient oaks, and their presence shows that there has been a long continuity of these trees.  Likewise their survival will depend on this continuity.

 

Mosses and liverworts

Epiphytic mosses grow on old and ancient trees in a variety of microhabitats such as rain tracks, exposed roots, sheltered sections of bark, cracks and crevices.  Each species prefers different conditions.  They usually grow fairly low down on ancient trees where they are particularly susceptible to agricultural contamination.  Old oak, ash, field maple and beech trees provide the best habitats for mosses. Hornbeam, sycamore and hawthorn also provide a good habitat.  Epiphytic mosses flourish on old trees where light reaches the boles of the trees whilst a high enough humidity is maintained.  These conditions are often created in wood pasture.

 

b)      Fungi

“Fungi  are fundamental to the growth of a tree and fulfil an important role at all stages in its life.”

Helen Read, 2000

 

Almost all plants form mutually beneficial associations with certain types of fungi, these are called mycorrhizal associations.  Mycorrhizal associations are essential to the health of most vascular plants, and trees are no exception.  Mycorrhizal fungi can give defence against pathogenic fungi as well as providing otherwise unavailable nutrients, usually phosphorus and nitrogen.  In exchange the fungi will take in carbohydrates, produced by photosynthesis, from the plant.  One oak may support and be supported by many different species of mycorrhizal fungi at the same time.  The fungi can stretch out many metres from a plant partner, often forming associations with other plants of the same or different species.  In this way a complex set of interactions takes place out of our sight within the soil.  Often no signs of the fungi are visible above the soil as relatively few species produce visible fruiting bodies, e.g. the agarics and the boletes.  In Surrey, the scarce Boletus radicans forms associations with oaks.  In healthy soil seedling plants can easily meet and make associations with one of the several species of fungi they need for healthy growth.  If the soil is ploughed the fungal threads, hyphae, are severed, and the soil structure drastically altered. It has proved impossible to grow more than a handful of species in culture or experiments.  Fungi are easily destroyed by soil disturbance.  The complex interactions between fungi and plants and between different species of fungi are known only very superficially (Merryweather, 2001; Gange & Brown, 1997).

 

Old and ancient trees often become hollow.  This occurs when the non-living heartwood is broken down by certain fungi. Trees can produce aerial roots to take in the nutrients recycled by fungi from the heartwood, or individual limbs.  Trees benefit from the release of previously locked-up nutrients that occurs in this process.  They also become lighter, which is helpful for the roots (less likely to uproot) and more flexible in winds.  The various species of fungi that inhabit non-living wood do not affect the surrounding live wood.

 

Many of the rarest fungi in the UK are those that hollow out old trees and those that form mycorrhizal associations with old trees.

 

Also important are species which decompose leaves and fallen wood.  The dung of grazing animals provides a habitat for fungi, although most species are intolerant of chemicals, such as ivermectins (a de-worming treatment), excreted in the dung.  

 

Species such as the oak polypore, Piptoporus quercinus (Buglossoporus pulvinus), and the tree hedgehog, Hericium erinaceum, depend on the dead and fallen wood of old trees.  Both of these endangered fungi are present in Surrey.  Their future depends on the continuity of old and ancient trees, on standing dead wood, and on allowing fallen trees and boughs to remain intact on the ground.

 

The range of fungi and fungal activities produce food and / or shelter, in and around mature, old and ancient trees, for a range of other organisms.  These include invertebrates, birds and bats. 

 

c)      Invertebrates

Dead wood is an extremely important habitat for a variety of invertebrates.  Up to a third of woodland insects, including a large number of rare species, are saproxylic (dependent on dead wood).  Saproxylic species have been identified as the most threatened community of invertebrates throughout Europe (Read, 2000).  The two invertebrate groups with the highest numbers of saproxylic members are the flies (Diptera) and the beetles (Coleoptera), each of which have many hundreds of species dependent on dead or decaying wood.  Surrey is an important county for many wood pasture and parkland invertebrate specialists.  Rainieria calceata is a stilt fly that is only found in Surrey and in Windsor Great Park (Surrey and Berkshire).  The heart moth, Dicycla oo, depends on old open grown oaks in wood pasture and Ashtead Common is one of the very few places in Britain where it is found on a regular basis.  Surrey is the national stronghold for this scarce species. 

 

Dead wood in partial shade supports the most invertebrate species.  Some species are active decomposers; some feed on the fungi that grow on dead wood; and others are specialist predators and parasites of the dead wood habitat.  However specialist species such as some solitary bees, wasps, and longhorn beetles can depend on sunbaked dead wood.  Dead wood in a range of situations provides a variety of habitats, all of which will be used by some of the many different invertebrate species.  Aderus ocultus is a beetle which depends on the dead wood of stag-horn oaks.  Rot-holes in mature and ancient trees provide a habitat for the hoverfly, Callicera aurata.  On heathland sites this species may depend on rot-holes in silver birch trees.  For some specialist species the unusual and precise conditions required will mean that very few trees provide them with the right habitat. 

 

Tree stumps left in situ are vital for several specialist species.  The stag beetle, Lucanus cervus, is an important Surrey species and its larvae develop in the wood of old stumps.  Also in Surrey, the tree ant, Lasius brunneus, depends on old oaks and limes and dead tree stumps.

 

Many saproxylic invertebrates have a saproxylic larval stage but become predators, pollen or nectar feeders as adults.  The retention of nectar sources, such as hawthorn, bramble and other flowers, close to host trees is important, as many of these invertebrate species do not travel far.  Ischnomera cyanea, a metallic, greeny-blue coloured flower beetle, feeds on hawthorn and hogweed flowers as an adult and the larvae develop in rotting wood.  Psilota anthracina, a metallic-blue coloured hoverfly, breeds in sap-runs where its larvae will develop, whilst the adults feed on hawthorn flowers. 

 

Invertebrates often require different habitats at different stages in their life-cycles.  As wood pasture and parkland consists of a range of habitats it can provide an ideal overall habitat for such species.

 

Isolation and fragmentation of the remaining parkland and wood pasture sites has become a problem.  Many of the species dependent on ancient trees are unable to move between sites due to their poor powers of dispersal and the increasing distances they need to travel.  This highlights the importance of ensuring availability and continuity of dead wood habitats.

 

d)      Flora

The ground flora of wood pasture is typically very species poor.  This is often due to grazing, and sometimes results in specialist ground flora such as heathland communities.  However unimproved neutral grassland can be very species rich with many broad-leaved flowering plants.  In Surrey wood pasture is usually of relic woodland and grassland species.  Relatively constant species are wood spurge Euphorbia amygdaloides and butchers’-broom Ruscus aculeatus, which are indicator species of ancient woodlands and persist in many of Surrey’s wood pastures.  Butcher’s broom is particularly common on Ashtead Common.

 

In parklands, the flora can be varied and sometimes an important habitat in its own right, such as the unimproved neutral grassland in Farnham Park, a former deer park, and the unimproved acid and neutral grasslands of Ashtead Common.

 

“An oak grows for 300 years,

Rests for 300 years,

And spends the next 300 years gracefully expiring”

An old English saying.

 

The ancient trees of Surrey’s wood pastures tend to be pedunculate oak, Quercus robur.  Ashtead Common has many pedunculate oaks of varying ages, many of which are ancient, often pollarded.  Beech, Fagus sylvatica, although not common within wood pasture, is found around the edges of sites where it has grown out from previously laid hedges.  Oaks, especially ancient oaks, are a habitat of immense importance.  Ash, Fraxinus excelsior, and beech also support diverse and intricate communities of epiphytes, fungi and invertebrates.  Albury Park has some ancient pollarded sweet chestnut trees, Castanea sativa.

 

Slow growing and maturing trees generally support the most interesting range of species, however the faster growing trees can also be important.  Birch, Betula spp., provides a habitat for a good range of dead wood species relatively quickly.  Many species, normally associated only with ancient oaks, will be present on younger oaks or such species as sweet chestnut when in close proximity to an ancient oak.  However once the ancient oak has gone the dependent species will disappear from the surrounding trees.  Where there is a gap in available ancient oaks, nearby ancient sweet chestnuts can provide a temporary habitat for many species.  Horse chestnut, Aesculus hippocastanum, has good sap runs and supports a good range of species and sycamore, Acer pseudoplatanus, supports a reasonable range (Read, 2000).

 

In some parklands both oak species are found: Q. robur and the sessile oak Q. petraea.  as well as ash, open grown beeches, and a variety of other native and foreign species.  These are found growing amidst varied settings, from the very open spaces typical of deer parks, to a mixture of scrub, woodland, streams, lakes and open grassy or heathy spaces. 

 

 

e)      Birds

Woodland and scrub often have the greatest diversity of species along their margins, where birds can take advantage of both the open surrounding habitats and the woodland cover.  Wood pasture and parkland can provide large areas of mixed habitats that are beneficial to many species, particularly where grazing is not intensive and more cover is available.  Nightingales, Luscinia megarhynchos, will nest where mixed scrub is present in dense patches.

 

Dead wood provides valuable nesting sites for birds such as tits, Parus spp., nuthatches, Sitta europaea, woodpeckers (green, Picus viridis, great spotted, Dendrocopus major and lesser spotted, D. minor), stock doves, Columba oenas, tree sparrow, Passer montanus, redstarts, Phoenicurus phoenicurus, jackdaws, Corvus monedula, starlings, Sturnus vulgaris, and owls.  One third of all woodland birds nest in holes or cavities in dead trees.  Although a few species will excavate their own holes in mature and ancient trees, most rely on ready-made cavities or those previously excavated by woodpeckers.  Kestrels, Falco tinnunculus, grey herons, Ardea cinerea, and buzzards, Buteo buteo, will nest where there is not regular disturbance by humans.  Buzzards are now breeding in Surrey in private parks.  Park woodlands are of importance for grey herons and nearly all the herons that nest in Surrey do so in areas of parkland without public access.

 

Wood pasture and parkland are especially good for tawny owls, Strix aluco, and little owls, Athene noctua, both of which nest in tree holes in old and ancient trees where open spaces are available.  Barn owls, Tyto alba, will sometimes nest in tree holes.

 

Fallen dead wood, left to lie, provides food in the form of invertebrates and also snow-free feeding sites in winter for ground feeding birds.  Large clumps of bramble separated by grass form a good habitat for invertebrates and small birds and again a winter feeding area. 

 

Grassland and heathland of wood pasture and parkland provide a habitat for many species (see the relevant HAPs) and these sometimes need specific management.  For example the skylark project in Richmond Park (Old Surrey) where the main nesting area for the ground nesting skylark, Alauda arvensis, is given protection from humans and dogs during the breeding season.

 

Mandarin ducks do well on parkland waters.  Although a non-native species these birds are internationally important.  In China, their native country, they are a seriously threatened species.  Britain and Japan now support the main populations.

 

 

f)       Mammals

All of the 16 British bat species depend on trees to some extent, and will forage for insects around trees.  Many bat species will roost in mature and ancient trees.  Several species of bat use ancient trees to hibernate in, finding cracks and crevices to hide in, particularly in hollow trees, where they are protected from weather changes within a thick walled cavity.

 

Noctules, Nyctalus noctula, and Pipistrelles, Pipistrellus pipistrellus, have been recorded at Gatton Park, as have Daubenton’s bats, Myotis daubentoni, which hunt over the water and frequently use trees as roosts.  In Surrey noctules are dependent on old and ancient trees, they roost mainly in rot-holes and woodpecker holes. Leisler's bat, Nyctalus leisleri, is rare in Surrey and will roost in trees.  The whiskered bat, Myotis mystacinus, is found in open and wooded country and will roost in trees, it is likely that it uses suitable trees for hibernation as well.  Serotine, Eptesicus serotinus, and Bechstein’s bats, Myotis bechsteinii, are both southern species and of importance in Surrey.  Bechstein’s are particularly dependent on this habitat as they roost exclusively in trees, usually using woodpecker holes, they are extremely rare in Surrey as elsewhere.

 

The rich invertebrate populations associated with old and ancient trees are an attractive food source for many species of bats. Many species will forage for food around open grown trees.  The brown long-eared bat, Plecotus auritus, will feed around ancient trees but stays very close to its roosts, usually within 2 km.  Most species of bat will only fly along hedgerows or near woodland margins, not venturing out into open spaces.  However noctules and serotine bats are happy to fly across open areas.

 

It is mandatory to seek advice from English Nature before carrying out any work on a tree which is a known bat roost.  This applies whether or not the bats are present at the time.

 

Roe deer, Capreolus capreolus, is the only native deer species to be found wild in Surrey.  Roe deer and the introduced muntjac deer, Muntiacus reevsi, are found in wood pasture only where they can remain close to woodland.  Fallow, Dama dama, and red deer, Cervus elaphus, are often present in enclosed and managed wood pasture and parkland.

 

Other mammals such as stoats, Mustela erminea, weasels, M. nivalis and mice will use holes in ancient trees, including those at ground level.  Wood pasture and parkland can be of importance for badgers, Meles meles. 

 

g)      Reptiles and amphibians

All of the native and introduced species of amphibian and reptile may be encountered in wood pasture and parkland.  The habitat is of importance for the great crested newt, Triturus cristatus.  Newts, toads and frogs will use pools for breeding and the surrounding areas for foraging.  Common toads, Bufo bufo, in particular are associated with wooded areas.  

 

Wood pasture and parkland provide hibernation sites for amphibian species, especially amongst the roots and bark of fallen and mature trees in wetter areas.      Reptiles and amphibians use cavities and loose bark on over-mature and ancient trees to rest in. 

 

Of the reptiles, the grass snake, Natrix natrix, will regularly hunt in pasture.  The adder, Vipera berus, slow worm, Anguis fragilis, and common lizard, Lacerta vivipera, will also use this habitat for foraging and as “corridors” for moving between other habitats. 

 

 

 

2.     Current Distribution and Status

 

Surrey is a stronghold for wood pasture and parkland, having a relatively large amount of the habitat, with many ancient trees.

 

Some of the main wood pasture and parkland sites found in Surrey include:  Ashtead Common (an important site nationally, ranking in the top 10 as a National Nature Reserves in Britain), Albury Park, Windsor Great Park, Gatton Park, Farnham Park, Gravelly Hill, Wotton Estate, Wisley Royal Horticultural Society Gardens, Witley, Peperharrow, Henley Park and Hampton Estate (including Puttenham Common).  The National Trust owns many wood pasture and parklands sites of interest in Surrey e.g. Hatchlands and Bookham Common.  There are also many other wood pasture and parkland sites under various ownership in Surrey.  The “Surrey Historic Landscape Characterisation” gives further details of the extent of this habitat in Surrey (Bannister, 2001).

 

 

Natural Areas and Wood Pasture & Parkland in Surrey

 

Natural Areas, defined by English Nature, are sub-divisions of England, each with a characteristic association of wildlife and natural features.  They provide a way of interpreting the ecological variations of the country in terms of natural features, illustrating the distinctions between one area and another.  Each Natural Area has a unique identity resulting from the interaction of landforms, geology, land use, wildlife and human impact.

 

Surrey contains five Natural Areas: the London Basin, High Weald, Low Weald, North Downs, and Wealden Greensand.  Of these, the London Basin contains the most interest for wood pasture and parkland, and is indeed of national importance for its parklands and ancient trees.  At Ashtead Common, Richmond Park (Old Surrey) and Windsor Forest and Great Park, oak pollards and ancient trees predominate.  These sites support nationally important communities of fungi, lichens and invertebrates and are covered by a variety of statutory designations.  These include statutory sites: Special Areas of Conservation (SACs), National Nature Reserves (NNRs) and Sites of Special Scientific Interest (SSSI), and non-statutory sites of county importance selected as County Wildlife Sites otherwise known as Sites of Nature Conservation Importance (SNCIs).

 

                                   

3.     Factors Affecting the Habitat

 

·        Cessation of traditional management.  Lack of treatment has been a severe problem with ancient pollards.

·        Lack of younger generations of trees, producing a skewed age structure, and a discontinuous habitat for species dependent on ancient trees and dead wood.

·        Loss of ancient trees through disease, physiological stress, such as drought and storm damage, and competition for resources with surrounding younger trees.

·        Soil cultivation too close to trees.

·        Removal of ancient trees and deadwood through perceptions of safety and tidiness where sites have high amenity use, forest hygiene, the supply of firewood or vandalism.

·        Loss of ancient trees through lack of understanding of their needs.  Contractors often have no experience of best methods when dealing with an ancient tree.  It is easy to kill an ancient tree by over-cutting.  Different tree species and individual trees will respond differently to tree surgery.

·        Loss of associated species when an ancient tree undergoes inappropriate tree surgery.  Table 3.1 gives the best times to work on an ancient tree taking its dependent associated species into consideration.

·        Loss of species associated with ancient trees from surrounding mature or younger trees if an ancient tree is lost.  Many dependent species can live on other trees only in the presence of an ancient tree.

·        Damage to trees and roots from soil compaction and erosion caused by people, trampling by livestock and from car parking.

·        Changes to ground-water levels leading to water stress and tree death, resulting from abstraction, drainage, neighbouring development, roads, prolonged drought and climate change.

·        Isolation and fragmentation of the remaining parklands and wood pasture sites in the landscape.  (Many of the species dependent on old trees are unable to move between these sites due to their poor powers of dispersal and the increasing distances they need to travel).

·        Pasture loss through conversion to arable and other land-uses.

·        Agricultural improvement to pasture through reseeding, deep ploughing, fertiliser and other chemical treatments, leading to tree root damage, loss of nectar-bearing plants, damage to epiphytes and to the soil and fungal associations.

·        Inappropriate grazing levels: under-grazing leading to loss of habitat structure through bracken and scrub invasion; and over-grazing leading to bark browsing, soil compaction and loss of nectar plants.

·        Non-native species can drive out and damage natives.  Rhododendrons and grey squirrels are well known problems affecting this habitat.  In Surrey ring-necked parakeets, Psittacula krameri, have become naturalised along the Thames valley where they thrive in parklands such as Bushy Park and Hampton Court deer park (both Old Surrey) as well as Windsor Great Park.  The parakeets use nest holes in trees but there is no evidence to suggest that they pose a threat to native species (RSPB).  Muntjac deer, Muntiacus reevesii is a successful and sometimes problematic non-native species in this habitat.

·        Some fungi of this habitat grow on faeces.  The chemical components of today’s horse and dog faeces (e.g. ivermectins for horse de-worming) prohibit the growth of most fungi.

·        Air pollution impacts negatively upon fungi and bryophytes, lichen are particularly susceptible.  Ancient trees and many other vascular plants are also affected.

·        Pollution from traffic, e.g. salt run-off from roads and car parks.

·        Risk of fire, from lightning and from vandals, e.g. in hollow trees.  Also from bonfires where unseen root damage can prove fatal to a tree or can ruin soil structure and the ability of associated fungi and other “invisible biodiversity” to function.

 

 

Jan

 

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Trees

 

3

3

3

7

7

7

3

3

7

7

3

3

Bats

 

7

7

3

3

3

7

7

7

3

3

3

7

Birds

 

3

3

7

7

7

7

7

3

3

3

3

3

Epiphytes

 

3

3

3

3

3

3

3

3

3

3

3

3

Fungi

 

3

3

3

3

3

3

3

3

3

3

3

3

Invertebrates

 

3

3

3

3

3

3

3

3

3

3

3

3

Table 3.1 The ideal time of year to do work on ancient trees according to the organisms associated with them.  Note that the time for the tree is the most important as it is the habitat for all the other groups.  (After Read, 2000).

 

 

 

4.     Cultural Significance and Importance to People

 

It is likely that wood pasture represents an ancient habitat, dating back to the original wild wood.  It was also likely to have been abundant as a natural ancient habitat.  A well-accepted view of the vegetation before human interference, is of woodland with open areas of grass or heathland grazed by large herbivores (Vera 2000; Rose 1993; Rackham 1986; Green 2001).  As such it is of great importance.  Evolution is a process that happens over time.  The longer a habitat has been around and the more available it is, the greater the number of species that are likely to have become adapted to exist in it, and on or with each other.  Wood pasture demonstrates this richness and complexity in its biodiversity and in the interactions between its species.

 

The complexity of life associated with ancient trees, and with wood pasture and parkland, is part of the richness surrounding us and on which we depend.  It includes some relatively unexplored areas, especially in the “invisible biodiversity”, such as the changing and complex fungal associations of young, mature, ancient, dying and dead trees.

 

William Gilpin (1724 - 1804) the famous writer on the picturesque was inspired by the New Forest glades near his home at Boldre.  His ideas on landscape, put into practice by his nephew, William Sawrey Gilpin at places such as Scotney Castle,

have become part of the general consciousness.  The landscape of wood pasture and parkland is one in which people feel at home.  They enjoy the sense of place and enclosure of wood pasture, the ancient trees, the lakes and ponds and the views within and beyond parkland.

 

Ancient trees tend to inspire us and give us a feeling of awe.  This is not surprising, the time they span in one lifetime can take us back beyond our own family trees - few of us know our history for 30 generations.  They also span time back to the primaeval forest or wild wood.  An old oak may well be only three generations from the original wild wood and it and its acorns and seedlings are therefore of great interest genetically.

 

Britain is responsible for the majority of Europe’s ancient trees, Spain being the only other European country still to have a significant number of ancient trees (Green).  Butler (2001) as quoted in the introduction, states that our heritage of ancient trees and old growth wood pasture is one of the greatest contributions of biodiversity and cultural that we can make in Europe.

 

5.     Benefits to the Community and Private Sector

 

Wood pasture and parkland are used for grazing cows, sheep and deer, and can be part of viable economic farming systems.  Wood from wood pastures can be “harvested” as a renewable resource.  The conservation needs of wood pasture make non-intensive (extensive) farming carried out without chemicals an important aim.  There is much interest amongst consumers and retailers in purchasing produce from such “environmentally friendly” farming systems.  Many people are interested in the health benefits to themselves, the conditions the animals are kept in and the impact on the environment.  A well-managed wood pasture, in conservation terms, can provide all these benefits.

 

The large amount of wood pasture and parkland in Surrey helps to give the county its distinctive character.  Parklands make attractive places to visit for outings and for regular exercise.  Such resources make Surrey a desirable location for individuals and businesses.  Trees, lakes and open spaces are also vital in helping to maintain quality of life in a densely populated county.

 

 

 

 

 

6.     Potential

 

§         To bring derelict wood pastures back into positive management, often through restoration of grazing.  

 

§         To bring over-grazed wood pastures and parklands back into positive management, at optimum grazing levels.

 

§         To address the problem of gaps in generations of trees.  This can be achieved with a combination of planting for the future, specific treatment of younger to mature trees already present at a site and by planting some quick growing trees to help to provide dead wood.

 

§         To encourage landowners to leave an appropriate distance around trees especially ancient ones.  This is important for the trees’ health and allows dead wood to lie undisturbed where it falls. 

 

§         To promote the production of organic meat from an extensive grazing system.  Wood pasture and parklands are often ideal sites for conversion to organic production.  Promoting the meat from such sites as extensively produced and organic, can benefit the producer whilst helping to ensure a better environment for the biodiversity of the site.

 

 

7.     Current Action

 

i. Site Protection and legal status

A number of mechanisms exist to ensure the protection and conservation of wood pasture and parkland.  Ashtead Common, one of the most important sites for this habitat in Surrey is notified as a Site of Special Scientific Interest (SSSI) by English Nature, as well as being a National Nature Reserve (NNR).  Such sites are protected by specific legislation.  In addition, the beech/oak woods on the acid soils of Windsor Forest & Great Park (part of which occurs in Surrey) are in the process of being notified by English Nature as an internationally important Special Area of Conservation (SAC).  Other designations are identified in the Surrey Structure Plan and Local Authority Plans and highlight the importance of these areas within the planning process.  They include Areas of Outstanding Natural Beauty (the Surrey Hills and High Weald AONBs), Local Nature Reserves (LNRs) and the non-statutory Sites of Nature Conservation Importance (SNCIs).  Farnham Park is a proposed LNR and is already designated as an Historic Park.

 

Policy PE12 of the 1994 Surrey Structure Plan states that this habitat should be identified in Local Plans and that “development will not normally be permitted which would have a materially adverse effect” (The Future of Surrey’s Landscape and Woodlands, 1997).

 

Other protection includes the requirement for a felling licence from the Forestry Commission for most tree felling.  All applications for felling licences are assessed against the requirements of the UK Forestry Standard (1998) which takes into account biodiversity considerations.  Tree Preservation Orders (TPOs) and Conservation Areas, designated by Local Authorities, also help prevent unnecessary damage to, or inappropriate felling of, trees.  Individual trees and groups may be afforded protection under the Town and Country Planning Act, 1990.  Ancient trees are particularly at risk because felling for safety reasons is exempt from all of the above.

 

The value of the habitat and of individual old trees is recognised in various development plans and landscape designations by English Heritage, e.g. Farnham Park, designated an Historic Park.

 

There are also several important wood pasture and parkland sites without any form of designation, some of which are well-managed for conservation and others that have the potential for enhancement under appropriate management.  A co-ordinated approach is required to conserve such habitats by reversing the trend of habitat degradation and addressing the issues of continuity of habitat, especially in relation to ancient trees and tree ages.

 

The violet click beetle Limoniscus violaceus, thought to be present in Surrey, is one of several species which are fully protected under the 1981 Wildlife and Countryside Act, as are all nesting birds.  Bats are European protected species.  The acts also offer protection to their “place of shelter”, with authorisation needed from English Nature or DEFRA to do anything that would affect such sites, whether or not the animals are present.

 

 

ii. Management

 

“ 10,000 oaks of 100 years old are no substitute for one 500 year old oak”

Rackham, 1986.

 

There are several wood pasture and parkland sites in Surrey where conservation of biodiversity is a major consideration in current management practices.  Others, often former deer parks, are neglected to various degrees, and although many are still rich in important biodiversity at present, they will start to lose species without suitable management. 

 

The wood pasture of Ashtead Common is managed to ensure future generations of ancient trees.  Young trees naturally generated on the site are transplanted to chosen growing positions with very high success rates.  Pollards already present are managed but no new pollards will be created.  Instead, unpollarded open-grown trees will provide future generations of ancient trees.

 

The National Trust has recently carried out an investigation into the management of grazed parkland (Cox & Sanderson, 2001) and this, combined with the national and county habitat action plans, should help with awareness of best practice in wood pasture and parkland properties.

 

Some woods in Surrey were wood pastures so long ago that restoration should only be considered if the wood is otherwise of very poor value.  Nower Wood is recorded as having been a grazed woodland in the Doomsday Book but is now an important part of Surrey’s ancient woodland and is managed as such.

 

Current management needs

The main management requirements for wood pasture and parkland are:

 

¨      Grazing needs to be established at low intensity, i.e. extensive grazing.

·        The different groups of conservation importance in wood pasture and parkland have different needs.  Lichens thrive under slightly heavier grazing than that which is optimal for invertebrates and fungi.  Restricting animal access to various areas of a site can help with this situation.

 

¨      Care of mature, old and ancient trees:

·        Mature and older trees need to have an undisturbed area surrounding them. An open grown tree may achieve a canopy spread of over 30m at maturity.

·        The ground should  not be disturbed around trees.  Ploughing, trampling and car parking cause damage to roots and the sensitive mycorrhizal fungi essential for a tree’s health. 

·        Fertilizer applications are unnecessary and detrimental to the tree’s health, as are any chemicals.  These can damage or destroy the mycorrhizal fungi, leaving the tree unprotected against pathogenic fungi.  Trees in fertilized areas may appear healthy until times of stress, such as drought.

·        Scrub and young trees should not be allowed to encroach on the space needed around mature and older trees. 

·        Avoid altering the soil moisture with any new drainage that would affect mature, old or ancient trees.

·        If a tree has to have surgery, ensure that the minimum possible is carried out, by an expert on ancient trees.  Read (2000) provides a checklist to ascertain if felling or surgery are the best option and how much should be carried out.

 

¨      The next generation of trees:

·        This can be ensured by planting cohorts of new trees every 10 years.

·        Seed or saplings should be chosen from existing trees with good characteristics, e.g. from an ancient tree in the hope that longevity is genetically inherited; or a tree that responded well to pollarding if pollarding is to be continued with future generations.

·        Seeds or saplings should originate from the site where they are to be grown.  If this is not possible they should be from a nearby site, i.e. of local provenance.

·        Young trees need protection from grazing animals.

·        An oak may take 200 years before producing any dead wood.  To ensure continuity of habitat for species dependent on dead wood, some fast growing species can be planted to provide an element of dead wood on a site (although not a complete remedy this can help).  Where the problem is urgent more immediate solutions are required (as suggested below).

·        Trees that would otherwise be felled for thinning can be artificially aged e.g. by ring barking, and left to provide standing dead wood.  This is a temporary measure only.  Standing dead wood produced naturally on mature and ancient trees provides a better and more stable habitat.

·        Features normally associated with age can be artificially induced on carefully selected younger trees.  Examples include:  breaking branches or leaving coronet cuts instead of sawing off flush;  drilling holes in forks and crowns to increase water retention;  inoculating healthy heart wood with heart wood rotting fungi; damaging bark to induce sap runs or decay (Read, 2000).

·        Creating new pollards; see “Veteran Trees: A guide to good management” (Read, 2000) for a useful practical outline.

 

¨      Management needs to consider all the groups present or likely to be present, see table 3.1.

·        Chemicals and artificial fertilizers are detrimental to many groups.  Lichens in particular are very sensitive and hedgerows, between wood pasture and nearby fields, are essential to help prevent spray drift as well as providing wind breaks.  However it is preferable to have neighbouring fields chemical-free.

·        Lichens also need to have a certain level of light reaching to the tree trunk and for the trunk to be free of ivy.  Ivy can also smother bracket fungi.  However, ivy is not poisonous or generally harmful to trees, and provides a useful habitat and food source for other groups such as bats, bird, and butterflies.

·        Before any work is done on an ancient, old or mature tree, a bat expert should carry out a survey.  Bats can creep into tiny cracks.  If a crack is created by the weight of a large branch, the removal of the branch will close the crack and any bats within are killed.

·        Stumps of trees should be retained as a specific habitat for certain saproxylic species.  The stag beetle depends on such habitat for egg-laying and during its larval stage.  Surrey is an important county for stag beetles, an increasingly uncommon species.

·        Most invertebrates and fungi depending on dead wood prefer a shaded moist location.  Fallen wood should be left where it falls.  If it must be moved it should be placed in partial shade.  Living old and ancient trees continue to create more dead wood of different types (e.g. in the crown) and provide shade.

 

¨      Historic and landscaped parkland may have specific needs:

·        Avenues of old or ancient trees need to be maintained by ensuring there are future generations of trees.  Planting whole new rows of same species trees on either side of an existing avenue is one solution.

·        Perceptions of tidiness and safety issues need to be dealt with sensitively.  Solutions could involve restricting access around an ancient tree where surgery would otherwise be necessary.  Where “tidy” landscaping is perceived as important and there is public access, information boards can explain the importance of dead wood as a habitat for many groups, including many rare and endangered species.

 

iii. Advice

A number of organisations provide an advisory role for land managers and farmers, including English Nature, Surrey Wildlife Trust, the Ancient Tree Forum, the Woodland Trust, Forestry Commission, the Farming and Wildlife Advisory Group (FWAG), English Heritage, the Department for the Environment, Farming and Rural Affairs (DEFRA) and the Environment Agency (for pollution and water issues).  The type of advice provided includes guidance on management and restoration, along with advice on how to obtain grant aid for projects, and advice on the relevant legislation and codes of good practice for the protection of wood pasture and parkland.  FWAG also produces “Whole Farm Conservation Plans” and “Farm Biodiversity Action Plans” with the aim of integrating conservation objectives across the whole farm.  At a more local level the various countryside projects such as the Wey Valley Project also provide valuable advice with the aim of encouraging sympathetic management.

 

Invaluable tools for wood pasture and parkland managers include the English Nature Veteran Tree Initiative publications and the handbook “Veteran Trees: A guide to good management” (Read, 2000); and the practical handbook “Habitat Management for Invertebrates” produced by the UK Joint Nature Conservation Committee (Peter Kirby, 2001).

 

The Surrey Wood Pasture and Parkland Working Group will run training courses for landowners, contractors, graziers, advisers and officers in practical wood pasture and parkland management, creation, enhancement techniques and grant schemes.  These courses will be run from the year 2002.

 

iv. Research and Monitoring

English Nature undertakes regular monitoring of all SSSIs.  It is also in the process of creating a wood pasture and parkland web site and database (the trial website can be seen at www.blue-bag.com/project/parks).  Surrey Wildlife Trust carries out monitoring and surveying of wildlife sites in the county and holds a great deal of biological data and records.  The county of Surrey is particularly well recorded in most groups, bryophytes however tend to be under-recorded.  The “invisible biodiversity” of Surrey’s wood pasture and parkland is by its nature hard to see and at present is poorly recorded.  Actions in this HAP include identifying indicator species and increasing levels of monitoring.

 

Funding

English Nature grants

English Nature has a number of funding mechanisms to promote appropriate management within both SSSIs and the wider countryside.  These include a new Biodiversity Grants Scheme, which aims to assist groups in implementing actions that will meet the targets of the published Biodiversity Action Plans for habitats and species.

 

Forestry Commission grants

The Forestry Commission can only grant aid where there is at least 20% canopy cover, which is evenly distributed over an area, or where replanting will aim at creating at least 20% cover.  Assistance may be available for replanting groups of trees to ensure continuation of generations of old trees for the future.  Grant levels for new or re-planting would be on a net area basis.  These are up to £1350.00 per ha, over the net area planted, available over a five-year period, with 70% of the grant available in the first year and 30% in the fifth year.

 

A Woodland Improvement Grant may also be available and could contribute up to 50% of the cost of any appropriate project.

 

Both the new planting/replanting grants and the woodland improvement grants are available through the Woodland Grant Scheme (WGS).  The Forestry Commission administers this scheme to encourage management and planting for a range of benefits including timber, landscape, conservation, biodiversity and recreation.

 

 

Countryside Stewardship Scheme

The Countryside Stewardship Scheme makes annual and capital payments for improvement of the diversity and natural beauty of the countryside. The scheme is run by the Department for the Environment, Farming and Rural Affairs (DEFRA) / Rural Development Scheme (RDS).  It includes management and restoration of unimproved and semi-improved grasslands and the creation of wildflower grasslands on ex-arable land. and is open to farmers and non-farming land managers, voluntary bodies, local authorities and community groups.  The level of payment available varies depending on the work being undertaken, an example is £85 per hectare for conservation management of lowland pasture or £115 for hay meadows.  The scheme is limited to land where a ten-year agreement can be made.  Also the land must not be subject to management conditions through another grant scheme or through an existing legal requirement.  The Countryside Stewardship Scheme also provides funding for a range of projects under the Historic Parks Initiative and this is an important source of funding.

 

 

Organic Aid scheme

The Organic Aid Scheme is run by DEFRA / RDS and provides annual payments to facilitate conversion to organic produce and to support the retention and appropriate management of important wildlife habitats and features.  The scheme is available between 5 and 10 years for any agricultural land in England not already converted to fully organic produce.  The highest rate of payment is during the first years when the costs of conversion are greatest with grants between £50 - 450 per hectare for a 5 year period.

 

 

Additional sources of funding

The Heritage Lottery Fund (http://www.hlf.org.uk) can be used to fund environmental improvement for the public benefit.  Corporate sponsorship can provide an important contribution to delivering conservation management objectives.

 

Wood pasture and parkland can contain a mixture of important habitats.  If a site is already in receipt of a grant this may affect eligibility for other funding schemes.  However, this need not conflict with another grant, provided that different management activities are being paid for under each grant, i.e. double-funding is avoided.

 

 

 

 

 

 

 

 

8.     Objectives

 

National objectives

 

The National Habitat Action Plan objectives and proposed targets for wood pasture and parklan