Helmsley Estate, Yorkshire
A versatile, adaptive management approach to continuous cover forestry contributes to Resilient Multi-Purpose Forestry Gold Award.
Helmsley Estate, Yorkshire, Owned by The Rt Hon Jake Barnaby Duncombe and managed by Mr Tim Tolliss
Gold Winner: Duke of Cornwall Award for Resilient Multi-Purpose Forestry 2017
Helmsley Estate, which includes the stately home at Duncombe Park, is located near the village of Helmsley and within the North York Moors (NYM) National Park. The woodlands are managed by Tim Tolliss, who has worked on the estate for almost 40 years.
Over the past 20 years, he has favoured Continuous Cover Forestry (CCF) approaches to woodland management, applying the principles of CCF to the varied stands and woodland types at Helmsley. He continues to experiment and note what does and does not work. In large part, this versatile, adaptive management approach contributed to the award.
The estate comprises around 4,850 ha of mixed farming and ranges geographically from burnt heather grouse moors to sheltered dales and arable fields. There are around 640 ha of woodland on the estate, which are broadly divided into steep, fertile valleys that link the uplands with the lower plain and many plantations on the upland. The soils range from iron pans to brown earths overlying limestone. On the upland sites, the soil is thin, acidic but moisture-retentive and capable of growing high yielding crops. On the valley sides, it is thin but much more fertile. A series of public rights of way and permissive paths cross the estate.
The move to CCF on Helmsley Estate was born of economic necessity rather than ideology. The shooting of partridge and pheasant is leased to a syndicate that provides an important source of income for the estate. The need to provide cover for bird-rearing, along with the unsuitability of the steeper valley sides for clear-felling (due to erosion risks), has led Tim to adopt a CCF system.
Tim’s over-riding aim is to produce high-quality sawlog timber. Therefore, the timber market needs dictate what is harvested, and CCF gives a good spread of species and age classes.
Providing the mill with what it requires and not selecting according to age or height helps to promote management for a diverse range of tree species, thereby improving resilience.
A high level of species and structural diversity is considered the best way forward for a medium-sized woodland to pay its way and cope with current and future pests and diseases.
Recent developments in the forestry sector have created new markets for products from the estate. For example, the growth of demand for wood chips (for bio-fuel) has provided a market for smaller-dimension material from thinnings which was previously lacking.
Many parties and stakeholders are involved in the management of the woodlands. The estate owner consults with the shooting syndicate, forest manager and other organisations. These include the NYM National Park Authority, National Nature Reserve, Natural England, Ryedale District Council, UK Woodland Assurance Scheme (UKWAS) and Forestry Commission England (FCE).
The valley sites were the first to be managed on CCF principles. Here there is significant regeneration of ash, beech and sycamore, which now comprises five tree size classes.
Regeneration is dominated by ash, but in response to Chalara, this has been thinned to encourage the other species to compete. In the older area of the wood, up to nine broadleaved species (ash, oak, birch, beech, hornbeam, lime, sycamore, gean and willow) are regenerating within the plantations of larch, Sitka spruce, Scots pine and Norway spruce which are now reaching maturity.
The shooting syndicate is concerned that a move to solely deciduous trees will remove the cover necessary for their birds, so the broadleaved regeneration has been supplemented by tube-grown conifers. This is keeping the species mix high as well as providing aesthetic interest.
These conifers are now about 45 years old and starting to regenerate with the help of light management, ground preparation and weed control. Some western hemlock, a shade-tolerant species, is blowing in from neighbouring land and regenerating well.
Conifer plantations on the upland heath are reaching maturity and are producing fine timber due to a rigorous thinning regime. There are many benefits of the thinning policy in these stands. They allow control of light levels so that natural regeneration of desirable species can be properly controlled and so that weed vegetation can be suppressed.
Gradual thinning also helps to improve the wind fastness of upland stands while opening the canopy enough to allow free movement of air. This is increasingly considered an important benefit of thinning to maintain sanitary conditions and reduce the spread of fungal diseases, such as Dothistroma Needle Blight (DNB) in pine stands.
Pest and Diseases
Of particular concern at Helmsley are Chalara dieback disease in ash and Phytophthora ramorum in larch. Chalara has already been confirmed in woodlands on the estate, while P. ramorum has been located in not too distant woodlands. As a result, silviculture has been modified to minimize risks from these diseases. Broadleaved regeneration has been guided away from ash-heavy mixes by selective thinning to favour other species. Larch plantations now have sufficient understory of other conifer and broadleaved species that they could be felled if necessary.
Wildlife management is a critical consideration where the woodland is being managed on principles of CCF due to the potential impact on natural regeneration and future timber quality. In particular, deer (roe and fallow) and grey squirrels need to be managed carefully to minimise their overall population within the estate’s woodland.
Deer are a major cause of browse damage on tree seedlings, and there is a direct correlation between population size and successful natural regeneration.
Grey squirrels are a greater problem in maturing broadleaved stands, where they damage trees by stripping the bark to access sugars in the phloem.
In some years, the deer and grey squirrels have had a detrimental effect. But generally, control of these species is sufficient to allow broadleaf trees to grow unhindered. Conifers seem to suffer higher rates of damage, and new conifer growth must be protected by tubes at first.
Timber is sold standing to several buyers who have a long-term relationship with the estate. Their contractors work closely with Tim to achieve the best conditions for stand renewal. Thinning is generally carried out on the basis that the machine operator selects the trees to remove.
Tim believes natural regeneration favours genetically stronger plants that are well-adapted to the local soil, climate and aspect.
Deadwood (up to 10% of stand volume) is an important stand component and is left standing or lying. This has several benefits: increased biodiversity, improved nutrient recycling and soil conservation, and enhanced aesthetics.
Tim remembers planting trees in the Scottish Highlands in the 1970s (aerial fertilising, use of deep-ploughs) as “forestry despite the environment”.
The approach on Helmsley Estate is to first consider the environment, work with nature and intervene only where necessary and suitable to do so.
For further information visit: www.duncombepark.com
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Author: Mike Page