17th November 2016
ATF autumn visit to Wimpole
The Ancient Tree Forum held its October field meeting at the Wimpole estate in Cambridgeshire, now owned by the National Trust. Originally a small deer park (the first record is from 1302) surrounded by open fields, the Wimpole parkland has changed many times throughout its history.
Over the years, different owners employed different landscape designers and gardeners, who each left their mark on the landscape. One of the most influential was Capability Brown. The site is rich in veteran trees, and the surrounding farmland includes ancient boundary oak pollards. Another interesting aspect of the site is its saproxylic invertebrate fauna which is of exceptional richness, and includes European Red List species.
Our host for the day was Simon Damant (pictured above), one of the estate’s managers, who has responsibility for the site’s trees and woodlands. His extensive knowledge of Wimpole, enthusiasm for the site’s biodiversity value, and sympathetic management of the site’s veteran trees, impressed ATF’s trustees and supporters.
One of the first stops was at a prominent beech tree located in an area frequented by visitors, especially in summer months when many people picnic under the tree. The tree supports a number of Ganoderma brackets near the base of the trunk, and has been crown reduced in the past to reduce the likelihood of failure. This led to a discussion about risk management, given the prominent location of the tree. Simon discussed the difficulty he has in deterring people spending time beneath the tree due to the desire to keep this area ‘open’ and ‘natural’, which would preclude the use of standard fencing. Options discussed included constructing a low hurdle fence (which is less visually intrusive than standard fencing), letting the grass grow long to deter people from having picnics, and the fact that presence of people beneath the tree is linked to weather conditions – with people less likely to spend time there during high winds and weather that would increase the risk of failure.
This tree is likely to be a relic of the original two mile lime avenue which was planted in 1640. The avenue still exists, but many of the original trees were felled due to the changing tastes of the owner.
1000 trees are being planted by the National Trust at Wimpole, over a 10 year period. Some of these are hopefully the ancient trees of the future. It was noted that when planting new trees it is essential to ensure that they do not shade existing veteran trees; a distance of 35 metres from existing trees is recommended for new planting.
Fallen branches or trees used to be cleared up at Wimpole, but the site’s management plan now stipulates that they are left in situ where possible (the exception being in the main vistas). Simon explained that he has to take on board different interests, as well as conservation value, such as the historic landscape and people management. ATF visitors suggested that messages about the biodiversity and habitat value of decaying wood could perhaps be put across more clearly.
It was also noted that some landscape architects, like Capability Brown, actually wanted deadwood in the landscapes so as to avoid them looking new and sterile. This dead standing tree reflects the vision of these landscape architects and provides a valuable decaying wood resource.
This tree, on the edge of woodland, is a maternity roost for Barbastelle bats, a rare species of bat closely linked to wooded areas with high structural diversity. On this tree, the opening to this split has been kept open by squirrels, hence the round appearance to the opening, and a suspected dormouse nest was found at the base – an example of how young trees can be valuable for wildlife. Jim Mullholland, the ATF’s Training and Technical Officer, who has a particular interest in bats, recorded the roost, and explained the need for landscape-scale conservation due to the wide area over which the bats travel. Bats require a number of roost sites throughout the year but favour particular feeding grounds irrespective of where they are roosting.
The value of low intensity grazing for wood pasture sites was also discussed. This helps develop a diverse sward, with opportunities for a range of grassland species, whilst controlling (but not preventing) regeneration of trees – too much of which could shade the existing veterans.