Research at Thetford Chase Research Forest
Explore current and historical research carried out at Thetford Chase Research Forest.
Overview
Current and historical research trials include:
- forest growth and condition monitoring
- forest hydrology
- forest soils: carbon balance, nutrients and atmospheric pollutants
- tree health and biosecurity
- tree species, provenance and improvement trials
Forest growth and condition monitoring
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 (Scots pine)
Historical observations from the national and international monitoring networks represented at Thetford Forest (the Level II monitoring plot) have improved our understanding of how woodland ecosystems respond to environmental drivers such as air pollution and climate change. 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
Thetford Level II Plot: summary of historical measurements
Level II plots: intensive long-term monitoring of forest ecosystems (FR project page)
Meteorological data collected at Thetford (2006-2014). Government open-access dataset download
FutMon: Further development & implementation of an EU-level forest monitoring system
Forest hydrology
Canopy throughfall and interception
A detailed study of meteorological and precipitation data was undertaken in a stand of Scots pine at Thetford, in the Level II Intensive Forest Monitoring Plot. This has helped to measure, understand and characterise the passage of rainfall and the proportion of interception and capture by the forest canopy.
Outputs
An investigation of canopy throughfall and interception (FR project page)
Forest soils: carbon balance, nutrients and atmospheric pollutants
Atmospheric pollutants: deposition, processing, availability and recovery trends in forest soils
The presence of the Level II long-term Scots pine intensive monitoring plot at Thetford has enabled many important studies and widened our understanding of how woodlands, their wider ecology, and management practices affect soils and soil water in respect of atmospheric pollution, deposition and soil recovery.
Outputs
Vanguelova et al. (2010). Chemical fluxes in time through forest ecosystems in the UK – Soil response to pollution recovery. Environmental Pollution, vol. 158 , pages 1857–1869
Dissolved organic carbon (DOC) and soil carbon. Long-term trends
Studies within the Level II Scots pine monitoring plot at Thetford have also widened our understanding of how woodlands, their wider ecology and management practices affect soils and soil water in respect of long-term trends in soil carbon, DOC, the water-use efficiency of forest soils, and wider effects on flows.
Outputs
Swain et al. (2010). Carbon stocks and phenolic distributions in peaty gley soils afforested with Sitka spruce. Organic Geochemistry, vol.41, pages 1022–1025
Soil mineral weathering rates
A long-term study is ongoing in the Level II Scots pine monitoring plot at Thetford Forest (and nine other sites for comparison) to measure and understand the rates of decay of the mineralogical content under different forest types and in a selection of different soil horizons, to determine their respective contributions to overall soil chemistry. After 10 years, significant differences are apparent between each.
Outputs
Soil mineral weathering rates (FR project page)
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 at the Roudham block (Plot 67) 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)
Tree health and biosecurity
Dothistroma (red band) needle blight: monitoring and management
Prior to 2006, Corsican pine was the main species planted in the woodlands at Great Hockham. However, since the appearance and spread of Dothistroma Needle Blight (DNB) it is no longer planted. Extensive areas of the plantations at Elveden (x3), Hockham (x2), Swaffham (x2), Kings East, High Lodge, Mundford, Mundford West and Pickenham are monitored for the effects of DNB. We have investigated the effects of management strategies including alternative thinning and respacing regimes. Findings will help to guide future silvicultural decisions here and elsewhere in Britain.
Outputs
Current status of Dothistroma needle blight in Britain (FR pest & disease resources page)
Dothistroma needle blight (FR Pest & disease resources page)
Pathogens and hosts of Dothistroma needle blight (FR pest & disease resources page)
Dothistroma needle blight, DIAROD evidence base (FR research page)
Local dispersal of Dothistroma septosporum (FR project page)
Dothistroma aerial spraying trials (FR project page)
Social and Economic Analyses of Dothistroma Needle Blight Management (2014). FR Research Report
Dothistroma needle blight (2012). FR Field Guide
Brown & Webber (2008). Red band needle blight of conifers in Britain. FR Research Note 2
Brown et al. (2003). Red Band Needle Blight of Pine . FC Information Note 49
Ectomycorrhizal fungi: diversity, distribution and links with tree-health
A long-term trial is being undertaken in the Level II, Scots pine monitoring plot at Thetford of the beneficial ectomycorrhizal fungi associated with tree root systems. The study will help to determine whether there are significant changes in species composition and abundance in response to current environmental changes and stresses. Thetford Forest has also been useful for other studies of the large-scale diversity and distribution of ectomycorrhizal fungi, and how they drive biogeochemical processes and responses to environmental change.
Outputs
Tree health and ectomycorrhizal fungal communities (FR research page)
Tree species, provenance and improvement trials
Corsican pine: early species and provenance testing
This trial was planted in 1969 and enabled recommendations to be made for the further use and preferred seed origins in British forestry. The trial has been retained for demonstration purposes and may be of further interest in respect of any Dothistroma-tolerant material.
Outputs
Corsican pine (FR species page)
Breeding and production of conifers, Corsican pine (FR research page)
Steven (1934). Corsican Pine In Great Britain. Forestry, vol.8, Pages 14–24
Corsican pine: progeny, clonal, genetic gain and seed-source trials
A breeding population of over 900 higher-quality trees was identified in East Anglia between 1960-1985 and was subject to open-pollinated progeny testing and other tests at a number of sites, including Thetford. As a result, a population of 145 plus-trees has been re-selected for possible future breeding work and remains in-situ.
Outputs
Breeding and production of conifers: Corsican pine (FR research page)
Eucalyptus, snow-gum (E. pauciflora). Provenance trial, plus other cold-tolerant species
This trial was planted in 1985 and assessed in 2013. The Australian E. pauciflora sub-species debeuzevillei and niphophila demonstrated superior growth and survival at Thetford. Planted for comparative purposes, E. perriniana (cider gum) was found to survive poorly at Thetford and was indicated only for the warmest of British sites.
Outputs
Leslie et al. (2013). Growth and survival of provenances of snow gums (Eucalyptus pauciflora) and other hardy eucalypts at three trials in England. Scottish Forestry, vol.67, pages 30-39
Short rotation forestry (FR forestry resources page)
Eucalyptus species trial (frost-hardy species)
Prior to more recent interest in biomass / energy crops, eucalyptus had been largely rejected for production forestry in Britain. This trial at Thetford established in 1981, however, demonstrated excellent growth for some seed origins when assessed in 2003, with several species that survived the severe winters of the early 1980s. Nine species were tested: Eucalyptus gunnii, E. gunnii var. divaricata, E. archeri, E. coccifera, E. debeuzevillei, E. glaucescens, E. niphophila, E. nitens and E. nitens × E. parvifolia. The trial has been retained for demonstration purposes.
Outputs
Short rotation forestry (FR forestry resources page)
Species and provenance choice for adapting England’s woodlands (FR climate-change adaptation page)
Grand fir: provenance trial
Previously regarded as a minor timber species in Britain, comparing unfavourably with Sitka spruce in terms of wood properties, the current challenges of climate and tree-health indicate that grand fir may represent a useful option for species diversification. A trial in the High Lodge block, planted in 1979 has contributed to recently-updated recommendations that provenances from coastal Washington are preferred, or if unavailable then coastal British Columbia or coastal Oregon.
Outputs
Kerr and Stokes (2021). Summary of FR Seed Origin Trials on grand fir. FR Research Report
Species for short-rotation forestry (FR resources page)
Lodgepole pine provenance trial
Lodgepole pine was widely-planted in Britain during the 20th Century but largely fell out of favour due to the use of poor provenance choices, being planting on priority habitats and concerns regarding Dothistroma needle blight. However, evidence from this and other trials has helped to identify better-performing seed origins, and the species is still considered to have a place in future forest species diversification.
Outputs
Lodgepole pine (FR species page)
Breeding and production of Lodgepole pine (FR project page)
Mochan & Hubert (2005) Utilisation of Lodgepole Pine. FC Information Note 70
Brown (2008). Red band needle blight of conifers in Britain. FC Research Note 2
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 from an associated network of trials were published in 2018. Wood properties in respect of timber potential have also been studied recently.
Outputs
Kerr & McMinn (2018) Summary of FR Seed Origin Trials on Noble fir. FR research report
Nothofagus: species & provenance trials
Nothofagus species may be of interest for future forestry in GB in light of predicted climatic changes. N. obliqua (RON) is known for being more drought-tolerant than other species (which are currently cold-limited in Britain) and may benefit from climate-warming. It tolerates warmer and drier sites than N. alpina. This trial, planted in 1979 and retained for demonstration purposes, contains small plots but many provenances of N. obliqua and N. nervosa (PRN).
Outputs
Nothofagus obliqua (FR species page)
Species and provenance choice for adapting England’s woodlands (FR Climate Change adaptation page)
Pinus jeffreyi: provenance trials
Native to western North America and Mexico. Known as Jeffrey pine, Jeffrey’s pine, yellow pine and black pine. Known to perform will in the UK as a specimen tree, two trials were established at Thetford Forest in 1930 and 1987 to testing the performance of the species and seed origins under British conditions. Findings do not appear to have been published, but the two trials are retained for demonstration purposes.
Outputs
Pinus jeffreyi (FR species page)
Jeffrey Pine (USFS species page)
Exotic Forest Trees in Great Britain (1957) Forestry Commission Bulletin 30
Silver birch: provenance trial
Planted in 2003, this series of trials tested 64 British and Irish provenances, finding significant differences in height growth and enabling recommendations to be made for the northern movement of provenances by at least 200 km to benefit height growth, with only little risk of poorer survival, or even further according to current predictions of climate warming. The trial has recently been evaluated for the genetic basis of growth adaptations to local site and climate conditions. The trial at Elveden is believed to contain some of the highest-yielding birch in Europe.
Outputs
Silver Birch (FR species page)
Lee (2017). Choice of silver birch planting stock for productive woodlands. FC Research Note 030
Silver fir provenance trials
European silver fir is not currently widely-used, despite being one of the earliest non-native introductions to Britain but is now considered suitable for wider deployment for species diversification and use in continuous cover forestry. This trial, planted in 1966, tested 33 provenances from mainland Europe alongside examples of Caucasian and grand firs for comparison. Findings published in 2015 made recommendations for seed origins that performed the best under British conditions. Wood properties in respect of timber potential have also been recently studied and found favourable in comparison to Sitka spruce.
Outputs
European silver fir (FR species page)
Species diversification trials
Planted in 2018, to test 17 tree species for their suitability as potential alternatives to those which currently dominate UK commercial timber production. Both under-planting and clearfelled restock sites were used. Early results are encouraging and were published in 2025.
Outputs
Tree Species Diversity (FR adaptation measures resources page)
Species trials (multi-species)
Three trials established in 1927 (High Lodge), 1962 (High Lodge and Mundford blocks), testing the performance of many different broadleaves and conifers on freely-drained soils at Thetford, on sites typically dominated by pine species. The trials informed many species recommendations in late 20th Century British forestry and are relevant to current climate-resilient forestry interests. Both are retained for demonstration purposes.
Outputs
Creating mixed species stands (FR Climate Change Adaptation Measures page)
Tree species diversity (FR Climate-Change Hub Adaptation Measures page)
Forest Development Types (FR Tools & Resources page)
Reynolds et al. (2022) Alternatives to Corsican pine: evidence and experience from a long-term experiment in Thetford Forest. Quarterly Journal of Forestry, vol.116, pages 92-99
Western Hemlock: provenance trial
Western hemlock is classified as a ‘secondary’ forest species but is considered to have potential for future wider use in British forestry. This long-term trial, planted in 1962, tested 18 different seed origins. Findings published in 2020 recommended the use of provenances from Vancouver Island and the Cascade mountains of Washington and Oregon, on suitable British sites. The study recommended that further work was required to test the timber properties of British-grown western hemlock, which were later confirmed to be suitable for the requirements of British structural timber.
Outputs
Western hemlock (FR species page)
Provenance variation of emerging species, including western hemlock (FR project page)
Kerr & Trimble (2020). Summary of FR Seed Origin Trials on western hemlock. FR research report
Harmer et al. (2009). Report on survey of Western Hemlock PAWS. FR Research Report