Priority Habitats: Wood Pasture, Parkland and Veteran Trees
- Maintain and enhance all areas of veteran trees and their associated habitats through appropriate management, preventing any further loss or degradation.
- Increase the extent of parkland and wood pasture through restoration of degraded areas and expansion of existing areas.
- Improve knowledge of veteran trees, parkland and wood pasture through survey, research and monitoring
- Facilitate a better understanding and increase awareness of the value of veteran trees, parkland and wood pasture
Veteran Tree Targets
Vision Statement: Better protected ancient & veteran trees, managed appropriately to prolong their life. Increased recruitment of veterans from mature tree stock.
|1. To maintain the number of veteran trees in the Durham BAP area.||maintain||number||tbc|
Vision Statement: Better protected parkland managed by grazing of an appropriate level of intensity to maintain a mosaic of woodland and grassland habitat.
|1. To maintain extent of parkland in the Durham BAP area.||maintain||ha||tbc|
|2. To restore parkland sites to favourable condition in the Durham BAP area||restore||sites||2|
|3. Expand the area of wood-pasture and parkland, in appropriate areas, to help reverse fragmentation and reduce the generation gap between veteran trees by 2015.||expand||sites||1|
|4. To achieve favourable condition of parkland in the Durham BAP area||achieve condition||ha||5|
Wood Pasture Targets
Vision Statement: Better protected wood pasture managed by grazing of an appropriate level of intensity to maintain a mosaic of woodland and grassland habitat.
|1. To maintain the extent of wood pasture in the Durham BAP area.||maintain||ha||tbc|
|2. Restore wood pasture sites to favourable condition in the Durham BAP area.||restore||sites||2|
|3. Expand the area of wood-pasture and parkland, in appropriate areas, to help reverse fragmentation and reduce the generation gap between veteran trees||expand||sites||1|
|4. To achieve favourable condition of wood pasture in the Durham BAP area.||achieve condition||ha||5|
This plan is primarily concerned with veteran trees and habitats which contain veteran trees. Wood pasture and parkland are are the products of historic land management systems, and represent a vegetation structure rather than being a particular plant community. Typically this structure consists of large, open-grown or high forest trees (often pollards) at various densities, in a matrix of grazed grassland, heathland and/or woodland floras.
This plan also includes areas currently under agriculture, forestry or other land-uses which were formerly wood-pasture or parkland, but which still contain veteran trees of nature conservation interest. It also includes individual veteran trees that might have originated in deer parks or parklands long since disappeared, or have developed in hedgerows or church- yards. This is in response to the growing concern for Britain’s important holding of old trees.
There are no reliable figures for the extent of the resource in Britain although a figure of between 10,000-20,000ha is currently being used as the ‘best estimate’ of the habitat in a ‘working condition’ where management is at a level that sustains the habitat’s natural features (source: UK BAP). A much greater amount is thought to exist in an unmanaged condition or as trees within arable or improved pasture, or as managed trees within formal, ungrazed landscapes such as golf courses, historic properties and recreational parks.
Veteran trees can be native or introduced species and are defined as the oldest examples of a given species in an area, . For oak,as an example this is generally interpreted locally as 300 years (typically with trunk girths exceeding 750cm). For shorter-lived trees such as birch and poplar, this might be 200 years, but the definition is a rather subjective one that can vary between a county with many such trees and one with relatively few. Britain’s holding of old trees has international significance, as the frequency of them here is far greater than in most other parts of western Europe. In Britain, the veteran trees of wood-pasture and parkland in particular provide important micro-habitats for many internationally rare species, including certain fungi, lichens, bryophytes and a variety of ‘saproxylic’ (rotting wood-associated) invertebrates – particularly flies and beetles. These micro-habitats include attached and detached decaying wood, sap runs, heart-rot, water-filled rot holes, rotting stumps and invisible old roots. The fungi associated with veteran trees and the dead wood in turn provide a further microhabitat for many insects. Parklands may also provide a refuge for indigenous or otherwise valuable trees such as Black Poplar.
- Lack of younger generations of trees is producing a skewed age structure, leading to breaks in continuity of dead wood habitat and loss of specialised dependent species.
- Neglect, and loss of expertise of traditional tree management techniques (e.g. pollarding) leading to trees collapsing or being felled for safety reasons.
- Loss of veteran trees through disease (e.g. Dutch elm disease, oak dieback), physiological stress, such as drought and storm damage, and competition for resources with surrounding younger trees.
- Removal of veteran trees and dead wood through perceptions of safety and tidiness where sites have high amenity use, forest hygiene, the supply of firewood or vandalism.
- Damage to trees and roots from soil compaction and erosion caused by trampling by livestock and people and 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.
- Pasture improvement through reseeding, deep ploughing, fertiliser and other chemical treatments, leading variously to tree root damage, loss of nectar-bearing plants, damage to the soil and epiphytes.
- 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.
- Pollution derived either remotely from industry and traffic, or locally from agro-chemical application and nitrogen enrichment from pasture overstocking, causing damage to epiphyte communities and changes to soils.