Woodland Strategy 11.34 Mb - the Dorset AONB

Section 7
woodland needs to be monitored.
Rhododendron ponticum is a plant that is extremely invasive and dominates woodland to
the detriment of many other woodland species, particularly floral species. Without
appropriate management the continued increase of invasive non-native species will impose
long term changes to the composition and thus the biodiversity and economics of Dorset’s
woodlands.
In order to reduce the impact of these and other invasive species a co-ordinated, cohesive
approach needs to be adopted as well as ensuring that appropriate resources are in place
to facilitate this important aspect of woodland management.
Non-Wooded (open) Habitats
Heathlands, fens and native grasslands are important open habitat communities and all have
Habitat Action Plans relating to them. These habitats have been lost to agriculture, forestry,
mineral extraction and development. In Dorset the planting of conifers on heathlands had
led to a significant loss of this habitat type in the county although corridors and fragments
survived within the plantations. Today planting of conifers on heathlands and grasslands has
stopped and much work has been undertaken to restore sites to their former habitat type.
However, without a concerted, pro-active effort to manage these habitats they will continue
to be lost to the natural regeneration of trees and scrub..
Within the ‘heathland’ areas of East Dorset and Purbeck there are a number of ancient
woodland sites. These are extremely important, and very diverse, woodlands. They tend
to be situated where there is a change in the underlying soils and geology, usually on the
boundaries of the sandy soils of the heaths and the chalk soils of the valley slopes. For this
reason they are extremely biodiverse as they support species and populations associated with
both types of soils and geology.
Forestry plantations also play an important part in supporting the flora and fauna associated
with heathlands and grasslands. The term ‘forest’ describes the old hunting forests of the
past, which were made up of woodlands with large open heath and grassland areas, such as
the New Forest. Today’s forestry can, to a degree, re-create this mosaic of habitats through
restructuring the forest by clear-felling and thinning. This provides a diversity of age
structure and habitats within a large area, thus supporting a rich and varied population
of flora and fauna species.
The restoration and management of non-wooded habitats does not necessitate the complete
removal of trees. When considering the re-creation of non-wooded habitats, consideration
needs to be given to the habitat type and whether the retention of woodland or forest is
appropriate for biodiversity or landscape reasons. They provide a diversity of habitat,
species and structure, as well as replicating the successional stages that open habitats would
undergo through natural processes. These woodlands are particularly important to flora
and insect species and the species that depend on them, such as nightjars (Caprimulgus
europaeus) which use the woodland and forest edges to forage.
Fragmentation
Until quite recently new woodland plantings haven’t been managed strategically, this has led
to a fragmented woodland landscape made up of many small individual woodlands
Habitat fragmentation at a variety of scales has been widely linked with the decline of many
species globally. Over recent decades there has been a recorded decline in the biodiversity of
many semi-natural woodlands and open habitats despite protection through designations
such as Sites of Special Scientific Interest and National Nature Reserves. The long-term
viability of woodland biodiversity, which evolved within a highly connected and extensive
habitat, is threatened by fragmentation of habitats and landuse, as it leads to smaller and
more isolated woodlands.
Fragmentation or isolation of veteran trees is also an issue as micro habitats and associated
species have little chance of colonising elsewhere. The number of truly ancient trees in
Dorset is quite small (Cooch, pers.comm.) and those old veterans that will become the new
ancient trees are often badly managed, cut down or blow over. More tree planting and
identification of future veteran and ancient trees needs to be undertaken.
Ecologists advocate the maintenance and improvement of connectivity between fragmented
woodland populations, with growing interest in the use of habitat networks to reverse the
effects of fragmentation by expanding and linking isolated habitats. Britain's woodland,
which may have once covered up to 75% of the land area, has been fragmented to such a
degree that less than 5% remained by the beginning of the 19th Century. Afforestation
throughout the 20th Century has increased woodland cover, however the ancient seminatural
remnant woodlands remain largely fragmented: new plantations provide
unfavourable habitat for characteristic woodland specialists, and are spatially unconstrained
while the surrounding matrix is often intensively managed, remaining unsuitable for
woodland species dispersal.
Species conservation through habitat networks has developed rapidly since the signing
of the Convention on Biological Diversity 1992. This has prompted some international
acceptance and emerging agreement of the need to conserve biological diversity using
an approach which includes the planning, establishment and adaptive management of
protected-area networks (Forestry Commission Information Note 073)
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