|
Castle Hill, Duncombe Park, Yorkshire – vandalised, burnt ancient
oak being released from forestry conifer planted ancient woodland
site. |
|
Occasionally ancient woodlands contain ancient trees especially
planted ancient woodland sites (PAWS).
Research undertaken by the Oxford Forestry Institute on behalf of
The Woodland Trust has indicated that more than one in every two
Planted Ancient Woodland Sites may contain ‘drowning’ ancient trees,
gradually being smothered by competing vegetation. In many of these
PAWS there may be just a scatter of ancient trees. However, in 7% of
the sites sampled, ancient trees were frequent. Many of these were
former wood pastures of great cultural value, which may have been
especially vulnerable to conversion due to their open canopies.
Relict ancient trees, coppice stools and fallen decaying wood,
hidden away or on the edges of many plantations, are invaluable
refuges for an amazing number of rare and threatened species
especially fungi, insects, bats and lichens. The old trees in
themselves provide real ‘hotspots’ of species abundance and
diversity and their crowns create gaps in the canopy which allow
flora and other species to survive within the general stand
‘matrix’. Even stumps of large trees can be important, representing
the tip of the iceberg of underground reservoirs of biodiversity.
And in four out of ten sites surveyed, whole felled trees remain
from the previous Ancient Semi Natural Woodland.
Restoration of sites with ancient trees will require special care.
Ancient trees and decaying wood habitats are very sensitive to rapid
changes in their microclimate.
Release ancient trees from surrounding competition:
- Gradually, perhaps over a decade or more
- Very carefully if it is the southern, sunniest, side of the
tree
- By removing direct canopy competition first but then from the
‘outside’ in
- Avoiding root compaction - at least 15
- 15 times the diameter of the trunk away from the tree
- In the right conditions e.g. not during or shortly after
droughts
- At least a year or more before any cutting of the ancient
trees themselves.
For further information on good practice see
‘Veteran Trees: A guide to good management’
For more information on ancient woodland see
http://www.woodland-trust.org.uk/campaigns
Full details of the Oxford Forestry Institute research |
