About the Action

About the Action

Action Summary

The ability of forests to continue mitigating climate change depends on their ability to cope and adapt to global change drivers, such as more frequent climate extreme events and changes in atmospheric pollutants (namely carbon dioxide, reactive nitrogen and sulphur compounds). Different global change drivers could play a synergistic, antagonistic or predisposing role in affecting forest ecosystem functioning and health. All these drivers, however, are generally considered in isolation, and their effects on key processes (at tree, soil and ecosystem levels) are investigated separately in natural, periurban and urban (NPU) forests, thus leading to uneven, un-coordinated and scattered information among different research communities. Without taking a holistic view on forest’s responses to global change, the future trajectory of Europe’s forests and their climate change mitigation potential can be fundamentally mis-assessed.

CLEANFOREST will establish an inclusive and multidisciplinary pan-European network, which capitalizes on existing expertise and infrastructures (monitoring networks, manipulation experiments) to i) coordinate research efforts (e.g. data collection), ii) compare approaches and define common protocols to standardize measurements and methods used in global change studies, and iii) foster collaboration among different research groups to exchange and synthesize data, thus contributing to advancing scientific knowledge, identifying research gaps and providing suggestions for the next generation manipulation experiments and monitoring networks. Finally, CLEANFORST will benefit from the participation of key stakeholders (policymakers, small companies developing low-cost and effective instruments for environmental monitoring, citizen associations), by promoting mutual synergies to fulfil the urgent need of evidence-based solutions to policy, societal and technological challenges.

Specific Objectives

Action Challenges

CLEANFOREST will address 3 scientific challenges, which call for a holistic perspective (both in terms of mechanistic processes, and expertise to study them) of the atmosphere-biosphere interactions along the continuum natural-periruban-urban (NPU) forests in Europe.

Spatio-temporal changes in global change drivers

Key questions:

(Q1.1) Where are the hotspots in the European forests that show the largest increase of the frequency of hot extremes and droughts in the last decades?

(Q1.2) Which are the main hotspots for atmospheric deposition?

(Q1.3) To what extent do these hotspots coincide, creating multi-factor hotspots of change?

(Q1.4) Is it possible to identify data gaps in the NPU forest continuum where intensive monitoring is necessary to mirror and/or complement existing networks?

(Q1.5) Are there cost-effective and easy to deploy methodological approaches that can extend monitoring of atmospheric deposition in less represented regions and/or in urban areas?

Interactions between global change drivers and forest ecosystems health and functioning.

Key questions:

(Q2.1) How do climate extremes and atmospheric N-S deposition interact and affect the response of European forests to increasing atmospheric CO2?

(Q2.2) Where does N and S deposition most strongly influence forest functioning, and how strong is their influence compared to other drivers such as forest management?

(Q2.3) To what extent is atmospheric deposition mediating sensitivity to drought events and why?

(Q2.4) Can we identify species and species assemblages that are more (or less) vulnerable to global change factors, in both natural and UF?

(Q2.5) Are trees growing near the species’ climatic tolerance more sensitive to global change components?

(Q2.6) Are there management practices that can improve forest resistance and resilience to hot extremes, drought and air pollution?

Interactions between global change drivers and tree and soil biogeochemical processes.

Key questions:

(Q3.1) Do forests become progressively N saturated, when moving across NPU forest gradients?

(Q3.2) How does N deposition affect soil organic matter turnover and N availability, but also N loss through nitrate leaching and N2O emissions?

(Q3.3) How do soil microbes respond to N deposition and what are the consequences for biogeochemical processes?

(Q3.4) Does high N availability result in deficiency of other essential nutrients, particularly P and K?

(Q3.5) How does the interaction between climate extremes and N-S deposition affect soil biogeochemical processes and rhizosphere dynamics?

Addressing these challenges calls for a synergy among different disciplines (climate science, plant physiology, atmospheric dynamics, atmospheric chemistry, land-atmosphere exchange, soil science, forest ecology, forest management, urban ecology) and methodological approaches (estimates of ecosystem CO2, water and N2O fluxes, dendro-isotope analyses, quantification of atmospheric N and S deposition, characterization of soil nutrients and soil microbial communities) and experimental set-up (e.g. monitoring networks; nutrients and moisture manipulation experiments).

Extensive work has been done within each discipline and topic listed in the Challenges, generating a tremendous amount of data. What is missing, however, is an international platform for interaction that ensures a FAIR and effective sharing of data and expertise across disciplines, and that allows a critical discussion on the most effective ways the different datasets can be integrated and used to answer the key questions we identified within each Challenge.

CLEANFOREST will build such a platform that integrates researchers from different disciplines, and foster exchange between researchers and stakeholders, with particular reference to policymakers defining current and future forest monitoring, management, conservation and restoration strategies.