Research at Yorkshire Research Forest
Find out more about the Yorkshire Research Forest and how long-term trials in forest health, soils, silviculture and tree species are helping inform resilient woodland management for the future.
Overview
Current and historical research trials at Yorkshire Research Forestt include:
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- forest growth and condition monitoring
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- forest soils: carbon balance, nutrients and atmospheric pollutants
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- silviculture: the cultivation and care of woodlands
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- tree species, provenance and improvement trials.
Forest condition monitoring
To successfully adapt UK forests to climate change we urgently need to understand how to diversify our productive tree species and determine how resilient they are to extreme climate events, particularly drought. There is a pressing need to develop methodologies to monitor tree growth and stresses that leverage both novel technologies and our current experimental infrastructure to identify which tree species / provenances are both productive and resilient to a changing climate, whilst also understanding how the characteristics of extreme drought events are changing as our climate warms.
At Wykeham Forest, we are using modern environmental sensors to measure the diameter growth of individual trees, in minute increments, along with other measurements of soil-moisture and below-canopy microclimate. This is providing unprecedented levels of detail and new scientific insights when quantifying the mechanics, timing and dynamics of tree growth and stress responses. This project is helping to inform our climate-resilient species and provenance choices for the future. We have established the foundation of a ‘Tree growth and stress monitoring network’, initially across five field trials, where we are continuously monitoring 355 trees in 72 replicated plots. Work is funded through the ADAPT (Assessing Drought Adaptation of Productive Trees) project, in partnership with Forestry England and Defra. We plan to expand the network with an additional 200 trees across new and existing sites during 2026/27, and plan to create a long-term UK-wide monitoring network.
Outputs
Assessing the resilience of UK forests to extreme climatic events (FR research page)
Climate Change Adaptation (FR research page)
Climate change impacts and adaptation in England’s woodlands (FR research page)
Ray (2010). Climate change: impacts and adaptation in England’s woodlands. FC Research Note FCRN201
The GB Dendrometer Network (Google Earth map showing locations of monitoring sites)
Intensive forest monitoring: Level II Plot (beech)
Historical observations from the national and international monitoring networks represented at Wykeham Forest have improved our understanding of how woodland ecosystems respond to environmental drivers such as air pollution and climate change.
The plot was monitored from 1991 until 2010. Historical datasets are available for foliar sampling and analyses, soil analyses, soil moisture, incremental growth of trees, crown condition, meteorology, atmospheric deposition of pollutants, concentration of pollutants (above and below canopy), ground vegetation, leaf litter-fall, soil chemistry and the growth-uptake of heavy metals.
Outputs
Further information about the Environmental Change Network (FR research page)
UK Environmental Change Network (UK CEH project page)
UK Environmental Change Network Data Repository
Wykeham Level II Plot: summary of historical measurements taken
Soil sustainability – Data sets from Level II Forest Health Monitoring Plots (FR research page)
FutMon: Further development & implementation of an EU-level forest monitoring system
Forest soils: carbon balance, nutrients and atmospheric pollutants
Soil sustainability
BioSoil is a demonstration project, part of the programme of the International Cooperative Programme on the Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests).
The project is a test for the development of operational soil monitoring at a large scale. A soil-survey plots was established close to the Level II forest monitoring plot (Plot 097) in 2006. Soil chemical and biodiversity components have been described, in order to establish a common European baseline of forest soils for further environmental research.
Open-access data are available for all of the British plots including pH, soil organic carbon, soil inorganic carbon, total nitrogen, base cations and heavy metals, bulk density and fragment content.
Outputs
Soil sustainability – Forest Focus – BioSoil (FR project page)
Forest Research BioSoil Data. Open-access data, available under Open Government Licence
Soil sustainability – List of all FR Publications
Integrated forest monitoring (FR research page)
Woodland creation and soil carbon and nutrient dynamics (FR research page)
Silviculture: the cultivation and care of woodlands
Continuous Cover Forestry: monitoring of transformation to CCF
An extensive area (c.240 ha) of Wykeham Forest has been managed since 2001 for transformation to CCF, informing much of the current official guidance. Stand development and seedling establishment has been intensively monitored, enabling prescriptions to be made for thinning in order to encourage natural regeneration of diverse species under a five-year cycle.
Outputs
Stokes & Kerr (2012). How can monitoring aid the management of the Wykeham ATC trial area? 2002–2012. Internal report to Forestry England, Forest Research
Forestry Commission (2008). Managing Continuous Cover Forests. FC Operational Guidance Booklet No. 7
Mason et al. (1999). What is Continuous Cover Forestry? FC Information Note 29
Heathland management and development
As a contrast to the many adjacent afforestation trials, an area of Broxa Forest has been left unplanted (for many decades), and is retained and monitored as an upland heathland natural reserve and control area. The area is kept clear of tree regeneration and is occasionally mown.
Outputs
Zehetmayr J.W.L. (1960). Bulletin no. 32, Afforestation of Upland Heaths, Forestry Commission, HMSO
Yeatman (1955). Tree Root Development on Upland Heaths. FC Bulletin 21
Natural regeneration: effects of thinning and extraction
In the area now covered by the wider Transformation to CCF trial (see above), a study was undertaken in 2005 to test the short-term effects of thinning and extraction operations on the advance regeneration of Scots pine and Japanese larch. The study enabled recommendations to be made for the positioning of racks and protection of taller seedlings.
Outputs
Natural regeneration of broadleaved trees and shrubs (FR research page)
Using natural regeneration (FR Climate Change Adaptation Measures page)
Natural regeneration: management for conifer & broadleaf mixtures
On some clear-felled sites, there can be abundant natural regeneration of a range of both conifer and broadleaf seedlings, often presenting a challenge for managers. A trial established at such a site in Broxa Forest in 2009 created four different mixture types by mechanical re-spacing: i) mixture left untouched; ii) broadleaves removed; iii) conifers removed; iv) Sitka spruce and western hemlock only removed. Treatments proved effective but not entirely persistent over time. Findings were published in 2020 and may be useful for managers needing to consider the relative shade-tolerance, growth rates and stocking density of various component species of a mixture, to determine whether early mechanical interventions may be necessary.
Outputs
Stokes, V. and Mason, B. (2020) Management options for mixed-species natural regeneration: results from an experiment in the North York Moors. Quarterly Journal of Forestry, vol.114, pages 268-273
Site amelioration: effects of cultivation and fertilising methods
Wykeham Forest has a long history of studies into the effects of different soil preparation techniques and artificial manures. One remaining extensive and complex trial was planted in 1971 to test the effects of various ploughing, planting and fertilising regimes on the establishment and long-term performance of Sitka spruce and lodgepole pine, with some smaller areas of grand fir and western hemlock. Research at Wykeham has informed current guidance, and the p.71 trial is retained for further research and demonstration purposes.
Outputs
Forest Research (2002). Forest ground preparation. Research information note ODW 10.01
Paterson & Mason (1999). Cultivation of Soils for Forestry. FC Bulletin 119
Taylor (1991). Forest fertilisation in Britain. FC Bulletin 95
Thompson (1984). Ploughing of Forest Soils. FC Leaflet 71
Thompson (1978). Forest Ploughs. FC Leaflet 70
Binns (1975). Fertilisers in the Forest: a Guide to Materials. FC Leaflet 63
Forestry Commission (1950). Report on forest research for the year ending march, 1950
Forestry Commission (1939). Progress report on forest research
Species mixtures: nurse crops (using conifers)
Established in the 1950s, this species mixtures trial contains Japanese, European and hybrid larches, lodgepole, Corsican and Scots pines, European silver and Douglas firs, Sitka spruce, western hemlock and Silver birch. Some provenance testing was included and has informed current guidance on choices of seed origin. Much of the original planting still remains and is retained for demonstration purposes.
Outputs
Lines (1996). Experiments on Lodgepole Pine Seed Origins in Britain. FC Technical Paper 10
Zehetmayr (1960). Afforestation of Upland Heaths, FC Bulletin 32
Under-planting or enrichment planting. Species introductions into established Scots pine plantations
In 1950, a stand of mature Scots pine (p.29) was under-planted using ash, alders, beeches, birches, firs (Caucasian, grand, noble, Veitch’s and white), Lawson cypress, larches (Japanese, hybrid larch and European), Monterey cypress, oaks (sessile and red), Ponderosa pine, spruces (Oriental and Serbian), sycamore, western hemlock and western red cedar. Findings have informed much of the current official guidance for creating mixed-species stands. The trial has been retained for demonstration purposes.
Outputs
Kerr, G. (2023) A long-term experiment shows that enrichment planting can diversify species composition and stand structure, Quarterly Journal of Forestry, vol.117, pages 28-34
Kerr & Haufe (2016). Successful under-planting. FC Silvicultural Guide
Mason, W.L (2006) Transformation of conifer plantations to mixed forests: initial guidance from an experiment in Wykeham, North Yorks. Quarterly Journal of Forestry, vol.100, pages 31-42
Creating mixed species stands (FR Climate Change Adaptation Measures page)
Structural diversification in woodland (FR Climate Change Adaptation Measures page)
Tree species diversity (FR Climate Change Adaptation Measures page)
Tree species, provenance and improvement trials
Eucalyptus: frost-hardy species and provenance trial
In recent decades there has been increased interest in planting Eucalyptus species for the woodfuel market. Studies in the 1980s identified individuals of three species – E. gunnii, E. debeuzevillei and E. niphophila – as being particularly frost-hardy under British conditions. A trial was established at Wykeham Forest in 1984 to test different provenances of these three species and has helped to inform our current understanding of their performance and potential uses.
Outputs
Eucalyptus gunnii / cider gum (FR species page)
Hubert & Cundall (2006). Choosing Provenance in Broadleaved Tree. FC Information Note 082
Noble fir: provenance trial
Noble fir has been classed as a ‘secondary’ species but is believed to have potential for wider use. This trial, planted in 1984, provides evidence for the most suitable choice of seed origins, in order that the species may play a wider role in future British forestry. Preliminary findings were published in 2018. Wood properties in respect of timber potential have also been recently studied and concluded to be suitable for load-bearing, whitewood construction timber.
Outputs
Abies procera / noble fir (FR species page)
Kerr & McMinn (2018) Summary of FR Seed Origin Trials on Noble fir. FR Research Report
Nothofagus: species and provenance trials
Nothofagus species may be of interest for future forestry in GB in light of predicted climatic changes. N. obliqua is known for being more drought-tolerant than other Nothofagus species (which are currently cold-limited in Britain) and may benefit from climate-warming. It tolerates warmer and drier sites than N. alpina. At Wykeham Forest there are three separate trials (est. 1978, 1982 and 1991) containing the Nothofagus species N. nervosa (PRN), N. obliqua (OBN), N. pumilio (NPU) and N. antarctica, including some diverse provenance comparisons. All are now retained for demonstration purposes.
Outputs
Nothofagus obliqua / Roble (FR species page)
Nothofagus pumilio / Lenga (FR species page)
Pacific silver fir: provenance trial
Pacific silver fir is currently considered to have considerable potential for British forestry. This trial, planted in 1985, has tested the performance of material from 14 seed zones located in the Pacific north-west of America. Findings were published in 2016, indicating little variation between seed origins. The plots have now been retained for demonstration purposes. Wood properties in respect of timber potential have also been studied recently, indicating suitability for the whitewood construction timber market.
Outputs
Abies amabilis / Pacific silver fir (FR species page)
Savill et al. (2016) Silver Firs of Europe and the Near East. RFS/QJF Species Profile
Abies amabilis (Douglas ex Loudon) Douglas ex Forbes (USFA / USFS plant profile)
Abies amabilis (entry in The Gymnosperm Database)
Pedunculate and sessile oak: provenance trials
In order to look at provenance differences at European level and investigate which might be suitable for Great Britain, this trial was planted between 1990 and 1992 as part of a series of replicated trials at six sites across GB, and alongside an extensive network across Northern Europe (the ‘Madsen Series’). Significant differences in performance have been identified, and early findings published in 2005 including recommendations for future provenance selection.
Outputs
Hubert & Cundall (2006). Choosing Provenance in Broadleaved Trees. FC Information Note 082
Red oak: provenance trial
Red oak can produce valuable timber. It grows faster than our native oaks and is well-suited to a warming climate. This trial was planted in 1992 and is building an evidence base for the use of this species in British forestry. The study and also seeks to identify suitable seed origins. Noting vulnerability to grey squirrel damage, early findings published in 2022 indicate that yield classes on productive sites typically exceeded those of native oaks. Recommendations were made that latitudes between 41°N and 44°N from the Great Lakes region should be the preferred source of any directly imported seed.
Outputs
Quercus rubra / red oak (FR species page)
Kerr et al. (2022). Summary of FR Seed Origin Trials on red oak. FR Research Report
McG. Wilson (2018). Alternative Oaks (Quercus spp.). RFS/QJF Species Profile
Scots pine: provenance trial
Scots pine is an important and adaptable species in British forestry and is likely to be vital in creating climate-resilient future woodlands. FR has recently updated its Scots Pine Breeding Programme to include resilience to biotic and abiotic stresses as a key objective. A new trial at Wykeham Forest, planted in 2026, is testing material from the native Scottish seed origins alongside material from Norway, Spain, the Czech Republic, Switzerland and Italy. We will measure growth performance and assess the local adaption and adaptability of these provenances and expect that our findings will allow improved guidance on provenance selection in British forestry.
Outputs
Infusing resilience into the Scots pine genetic resource (CFP project page)
Investigating Scots pine resilience (CFP project page)
Tree improvement (FR research page)
The breeding of conifer species (FR research page)
Provenance trials of native tree species (FR Forestry and Tree Health Resources page)
Species trials (broadleaved trees)
Various plots of alders, birch, oak and chestnut species were planted at Broxa Forest by Professor Dimbleby in the 1950s, including some uncommon species. Many survive and are still retained for demonstration purposes.
Outputs
Zehetmayr (1960). Afforestation of Upland Heaths, FC Bulletin 32
Forestry Commission (1950). Report on forest research for the year ending march, 1950
Species trials (various)
Plots of sweet chestnut, sessile oak, beech, grey alder, silver birch, Nothofagus (x2 species), red oak and Scots pine were planted in 1955 using a Japanese larch nurse (now removed). The plots are retained as a demonstration site for the use of these species for upland, heathland afforestation.
Outputs
Gabriel et al. (2005). Growing broadleaved trees on the North York Moors. Results after nearly 50 years. Quarterly Journal of Forestry, vol.99, pages 21-30
Zehetmayr (1960). Afforestation of Upland Heaths, FC Bulletin 32
Sycamore Seed Origins Trial
An investigation of the performance of six British, two German, one French and one Danish provenances of sycamore, planted in 1992. Early and mid-rotation findings were published in 1998 and 2021. Growth and form differences between provenances have not been significant at this stage, and findings do not currently enable provenance recommendations to be made for planting in England.