Visit to Kyloe Wood in Northumberland
by the Continuous Cover Forestry Group on Friday September 29th 2006
Rik Pakenham
The wood came into the possession of C.J.Leyland of Leyland Cypress fame in 1900. Leyland was a retired sea captain who had travelled extensively and wanted to make Kyloe a repository for a collection of conifers. Part of the eastern area known as Old Wood was already woodland; the remaining area was established over the next 30 years, which quadrupled the original size.
The current owners purchased the wood in 1986. The total area is 390 hectares, of which 326 are conifer, 32 broadleaves and 32 unplanted. Altitudes range from 91 to 200 metres. Average rainfall is 625 mm, which is supplemented by the ‘sea hags’, sea mists that regularly hang over the woodland, increasing the moisture and allowing many trees to survive and grow to large sizes similar to their native habitats, and an abundance of lichens usually associated with wetter climatic zones.
Soils range from Boulder Clay, Fell Sandstone and Quartz Dolerite to the Scremerston coal group. Some of these soils overlie limestone. Old coal shafts are found in the wood and lime kilns once flourished nearby.
At one time over 146 species and varieties of conifer grew in normal forest conditions. Some of these have been lost to time and gales, plus considerable replanting during the 1940s. Now 16 conifer species are well represented plus a further 80–90 still growing on the site.
The woodland has recently been designated as a Red Squirrel Conservation Reserve, to try to preserve this species. How long this will be sustainable with Grey Squirrels within 12 miles of the woodland, both to the north and south is debateable.
 Figure 2 |
The management objectives are varied, taking into account the history where this is the only site in Europe in which many of the tree species are grown in forest conditions rather than parks or arboreta. Other considerations were landscape, areas of long term retention, nature reserves and particular micro climates such as rock faces and gullies. They can be summed up as ‘retain the status quo with the minimum of cost’.
The day was attended by over 30 people from all three GB countries.
It was led by Peter Hale the agent, Ian Robinson forest manager and Mark Yorke secretary to the CCFG, with other specialists speaking at various stops.
The first stop set the tone for the day with much debate, interaction and varied experiences from the three different countries being shared. This highlighted the huge variance between the countries governed by different forest strategies, guidelines and grant aid.
The discussion centred on a stand of 1982 Sitka Spruce on a reasonably steep north facing slope, unbrashed, requiring its first intervention. As expected, a wide range of proposals were put forward, which of course was very interesting, but only went to show that managing a forest by committee is impossible. However the main points covered were:
How, when, and was the stand suitable to start the
conversion to CCF ?
Was the stand quality good enough to regenerate
from in the future ?
Was the labour resource available to carry out
‘faller select’ operations, and was it possible to do this
from a harvester in the low light conditions of dense
unthinned stands?
What sort of extraction was suited to these slopes?
If transformed to CCF management is it realistic to
expect that the larger more valuable timber eventually
produced will subsidise the early interventions?
Generally first interventions do not vary
considerably between CCF and plantation forestry
systems, line thinning access racks and or light interrack
removal being the primary aim for both systems.
For this stand this should be implemented sooner
rather than later so that stability is not compromised,
then all the other considerations can be addressed.
Whether this operation would produce income,
break even or make a loss was not clear!
Deer control and damage by Hylobius arbietis
(Large Pine Weevil) were discussed at the next stop,
a clear fall and restock area on the east side of the
forest overlooking the sea and Lindisfarne.
Roe are controlled, Fallow and Red being seen only
occasionally. 42 are culled annually, split 50/50
between bucks and does and concentrating on
yearlings.
If too many adults are removed this results in
greater numbers of pregnancies and multiple births.
Fencing is not used or deemed necessary, however
lack of natural regeneration in some areas,
particularly of Douglas Fir, is likely to be due to
browsing, therefore a possible increase in numbers
removed should be considered. This decision would
be aided by erecting exclusion plots to assess
browse levels.
Control in CCF stands was sometimes made more
difficult due to the lack of open space and this would
need to be addressed as younger stands develop.
Our next stop was in a magnificent stand of 1910
mixed conifers, including Corsican Pine, Douglas Fir,
Western Hemlock, Red Cedar and Sitka Spruce with
individual volumes of up to 5 m³. The owner was
reluctant to intervene, however the lack of
regeneration of the more light demanding species
such as Douglas Fir was due to the high basal area
[figures 1 and 2]. It was felt that up to 25% of the
larger trees should be removed to increase suitable
light conditions, help scarify the ground to aid
regeneration and free the range of younger age
classes already established. Western Hemlock and
Red Cedar regenerated freely throughout most of the
forest and may need to be controlled to favour the
more valuable timber species.
The marketing of large dimension conifer logs was
discussed with local saw miller Andy Scott.
However there is always a good market for large
Douglas Fir. Andy quoted the following approximate
value comparisons: Douglas Fir was four times the
value of Corsican Pine and two to three times the
value of Sitka Spruce at these dimensions. Large
Hemlock, Red Cedar and other species, apart from
Spruce, would most likely be milled down to smaller
sizes anyway and therefore it was not necessary to
grow to these large volumes. Pine at these sizes
would be virtually unmarketable.
Although CCF tended to produce larger individual
trees than plantation forestry, it was not necessary,
for timber production, to produce such large logs as
we were looking at.Therefore managing by target
diameter felling was one way to ensure a marketable
product for each individual species.
The other specie in demand, particularly in Scotland,
was European Larch but not Hybrid or Japanese which
was of inferior quality and it was suggested planted
only for amenity not timber production.
We walked to the next stop through spectacular
stands of mixed conifers, reminiscent of their native
habitats in North America [figures 3 and 4].
Here several small groups of up to 0.4 ha of mixed
conifers had been felled and replanted with Douglas
Fir. Western Hemlock regeneration in some areas was
sprayed out and other areas would be strictly
controlled.
We had a picnic lunch back at the old sawmill
where we had started the day. Here Phillip Wilson
of English Nature spoke about managing
biodiversity in CCF stands and the importance of
rides and open space.
In the afternoon we travelled to the stops by car
along the well roaded access routes.
We walked into a stand of Western Hemlock
[figure 5] approximately 50 years old with groups of
younger regenerated Hemlock, which would be
accepted within this compartment. Discussion
centred on a handout showing the reverse J-curve of
a transect taken through the stand identifying a range
of diameter at breast height (dbh) measurements
before and after the last intervention. The thinning
was heavier where groups of natural regeneration
existed, and the selected target diameter was
between 25-35 cm. After the thinning the reverse Jcurve
was much closer to the ideal than before.
The value of this type of monitoring as well as
assessing the number of seedlings (<130 cm tall) and
saplings (>130cm) was debated. Research showed
that there is a tendency to underestimate the number
of seedlings and overestimate those of saplings.
Although this sort of information is a very valuable
management tool, the costs of recording and
collating it are high. Under the previous Woodland
Grant Scheme monies were available to assist with
this monitoring, but are not now available in England
under the new scheme.
Next we passed a stand of 60 year old Scots Pine
growing on poorer soils with the ground flora
predominantly Bilberry and Heather. The lack of
weed competition had allowed impressive quantities
of Sitka Spruce to regenerate naturally. The
discussion centred on what to do next ? The
consensus was that, subject to the soils being
suitable, to thin the Scots, and depending on stability
and light regimes, adopt a group selection system to
allow the stand to develop. This would release the
Sitka and eventually allow a change of species. Some
Pines would be retained for landscape and
biodiversity. In the light of earlier discussions on the
different monetary values of the species and the fact
that they were here for free only went to reinforce
the change of direction.
Larch planted in 1945, with very patchy 15-20 year
old Larch regeneration beneath, was our penultimate
stop. The area had previous windblow damage and
the limited regeneration had probably established on
the extraction routes. The stand was thinned 5 years
ago to try to encourage further regeneration. The
ground flora consists of dense bracken and grasses,
so pigs were introduced to scarify the area. This was
not successful due to too few animals, and
supplementary feeding being carried out close to the
fence, so any ground disturbance was limited to
these feeding areas. If tried again, thinning should
coincide with a good seed year, so that seedlings can
establish prior to being swamped by weed growth.
Pigs could be used again, but with an increase in
numbers and fed across the site, and/or use chemical
control on some of the more aggressive weed
species.
At our final stop Axel Wellpott a PhD student
explained his experiments on measuring wind speeds
and turbulence within two adjacent stand types. He
will then compare these measurements with ones
previously taken in a wind tunnel. Firstly a two
storey stand of 25 metre Larch with an understorey
of 10 metre Larch and Sitka Spruce, and secondly a
similar stand with no understorey.
Two 30 metre masts were erected in each plot with
an array of instruments sited at different levels.
Preliminary results show that low wind speeds within
the stands are faster where there is no understorey,
but as the speed increases they become faster in the
stand with an understorey.
It is planned to publish the results in 2007 as a FC
Information Note.
Thanks to our hosts for a most enjoyable and
informative day and to the participants who shared
a wealth of knowledge from all parts of Britain.
Also thanks to Sharon Rodhouse for the use of
her notes and Doug Earle-Mitchell for his
photographs.
Should crown or low thinning be used ?
Was it already too late for the first intervention?
Was it better, if stability was not compromised, to
combine the first and second thinnings to make the
operation more cost effective by being able to harvest
larger dimension timber? Or was the first intervention,
which is critical to stand development and future
structure, too late at this stage ?
Figure 3
Hylobius can kill or cause serious damage and
reduced vigour to young trees, principally conifers,
by totally or partially ring barking them. However
this is rarely a problem in CCF stands, and increases
with the size of the felling coup. It is generally
accepted that this is because trees that are left
standing act as hosts for the adults, whereas in clear
cut sites the beetle breeds in the cut stumps and then
feeds on the newly planted trees. One way around
this is not to plant for the first year, which may be
acceptable on poor sites, but on the better base rich
soils rapid weed regrowth and colonisation may be a
worse problem.
Most sawmill investment has been, and still is,
aimed at the high volumes of smaller diameter
plantation Spruce established over the last 50–60
years. Therefore the capacity to handle large logs is
limited and is more likely to be carried out by
hardwood mills which have experience of milling
both hardwood and softwood.
Figure 4
Respacing the Hemlock regeneration to 2 metres
had taken place when the average height was 2-2.5
metres, but in hindsight it was felt this was too early
as much of the Hemlock re-coppiced, or continued
to grow because the plant was not cut off below the
first branch whorl. Later experience from adjoining
areas showed the optimum height would be 4-5
metres, or if left until 6 metres the extra costs
may be defrayed by local markets taking some of
the produce.
Figure 5
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