ForeSight: Predicting and monitoring drought-linked forest growth decline across Europe

More intense drought and increased temperatures reduce tree growth and drive tree die-back and mortality across the globe. While this problem has been recognized for some time, the processes and geographical extent of forest growth reduction and die-off are not well understood. Predicting the response of Europe's forests to drought and temperature change a key challenge because forests have enormous economic and ecological benefits that will be impacted as climate warms and becomes more extreme.

Addressing this problem requires an interdisciplinary approach that brings together world-leading expertise in in forest ecology, Earth observation, dendroecology and process-based modelling. Our team has a strong record of scientific excellence and method development as well as expertise in transferring scientific advances into practical applications with international policy and economic impact.

We use European beech as an indicator species to study this problem because it is the most widespread broadleaf tree in Europe covering over 15 million hectares. Beech produces valuable wood with very diverse uses and it is known to be at high risk from drought-linked die-back and mortality.

Our research is highly novel because it will link together satellite observations and process-based models calibrated from the European Beech Tree Ring Network, a data network that provides a detailed picture of tree growth from about ten thousand individual trees across 25 countries. These data will enable us to model the processes of tree growth suppression and to map and monitor drought-stress vulnerability across the entire range of beech in near real-time.

We will advance knowledge of the response of beech to environmental variation and produce models that predict tree growth based on local climate and soil moisture across Europe. The models and tree ring data will provide a detailed picture of growth suppression and dieback risk. Furthermore, we will combine the site-specific models with satellite data to establish an open-source web-based monitoring platform that will form the basis for decision support for forest managers and policy makers. This project is highly timely, since cloud-based computer processing of satellite imagery now avoids the need to download and pre-process large volumes of satellite data. Such cloud processing makes data analysis at this scale efficient and cost effective, with outputs available to all via a simple web-based interface.

We will contribute major new scientific insights into forest growth reduction and die-off in response to drought, with substantial benefits for improving our understanding of impacts on our ecoststems and atmosphere. Furthermore, we will apply our research to provide operational guidance on species suitability and growth predictions for forest management. In the UK this will be achieved by working with Forest Research to improve their Ecological Site Classification Decision Support System for beech. The system is open to all and is widely used by foresters and policy advisers. Once adapted using our results for beech, these changes to decision support tools can be extended to other forest-forming tree species and will also underpin future planning of semi-natural woodland in the UK.

Our project outputs will give broad benefit from cutting edge research to forest decision support. We will map early-warning signals of growth decline and mortality and impacts of drought on growth across the entire range of European beech. We will predict future impacts of climate change on forest growth and mortality, improve estimates of forest carbon uptake and provide the tools to monitor these effects using satellite data. Overall, our research will substantially advance our understanding of past, present and future drought impacts on beech forest across Europe and provide the capability to monitor and manage our forests for the future.

Legal obligations exist for UK Government in preserving and reporting on the state of the natural forest environment across the national forest estate by the Forestry Commissions (UKFC), and across the whole UK through delivery of the National Forest Inventory. This proposal will deliver a step change in our predictive capacity for forest growth, climate suitability and future climate impacts. Through integration of process-based modelling of plot-level tree growth data, future climate scenarios, and monitoring capability we will deliver a revised model for forest management, species suitability and growth assessment (Ecological Site Classification Decision Support Service, ESC-DSS) for the most widespread broadleaf forestry type in Europe: beech dominated forests. ESC-DSS underpins future planning for the UK woodland resource, especially ecological resilience of semi-natural woodland.

Project outputs will have very broad benefit since the new methods developed here can be rapidly adapted to other forest types. At the UK level, the proposed pre-emptive assessment of the response of an iconic forest keystone species is increasingly relevant as climate change impacts lead to changes in ecological suitability, habitat loss and/or displacement of the species range. Recent work showing that there is no convincing evidence to restrict the native status of beech to southern UK1 highlights the high value of this species for climate change adaptation at the national scale. At the European scale, requirements for maintaining beech forest habitat condition exist under the Habitats Directive, yet there is considerable uncertainty as to how these can be delivered as climate changes across the continent2.

Given the great local, national and international interest in forests and forest health, predictive knowledge and tool development from this project will benefit a wide range of stakeholders and interest groups:

Over the project lifetime:
Public interest and education via a forest health outreach event
Landscape ecology students and junior researchers
Forest Research (Civil Service Agency)

Mid-project - 3 yr+:
Funding agencies and donor governments, including UKFC and devolved administrations through evidence on future climate suitability, forest adaptation and conservation strategies for iconic British forests.
UKFC, DEFRA, forest enterprise and natural heritage agencies through evidence on likely changes in forest ecosystem structure and function.
Public and private sector forestry practitioners (via UK Royal Forestry Societies, Confederation of Forest Industries) and standards providers (UKWAS and FSC) through ESC-DSS and outcomes informing policy and practice on forest resilience and sustainability.
Organisations with a broader remit on climate change adaptation and mitigation including the devolved administrations and their associated centers such as the Committee on Climate Change (ClimateXChange) through outcomes on climate change impacts.
European groups seeking evidence for policy-making and national and EU long-term forest management planning such as Forest Research, European Forest Institute, International Union of Forest Research Organisations, European State Forest Association and national Forest Owners Associations through the Confederation of European Forest Owners.

Long term:
Lasting benefits will be gained by the above groups post-project.
Civil society: Landscape change is of great public interest throughout Europe. The management of landscape is a key concern especially regarding iconic UK forest types (Oak, Pine, Beech).
1Sjölund MJ, et al. (2017) Understanding the legacy of widespread population translocations on the post-glacial genetic structure of the European beech, Fagus sylvatica L. J. Biogeography, 44, 2475-2487
2Greenwood S. et al. (2017) In: Natura 2000 and Forests - Assessing the State of Implementation and Effectiveness. M Sotirov (Ed). European Forest Institute. Joensuu.