Crucial for tackling climate change, but limited by its own effects – how to help forests break the vicious circle

Forests are crucial in sequestrating carbon and achieving the targets of the Paris Agreement. Yet, their "mitigation effect" is increasingly limited by the effects of climate change itself. See how researchers and EU projects are working to unleash
their potential and break this vicious circle.

Jadav was only 16 when he made a resolution that would turn him into a global symbol of environmentalist fights against deforestation. Walking along the banks of the Brahmaputra River in India, he was shocked by the devastation of his cherished native Assam state. Likely exacerbated by climate change, the violence of the monsoons had turned what used to be a natural paradise into a cemetery of trunks and debris. Having grown up in a poor farmers' family from a marginalized tribal community, this son of a buffalo trader decided then that he would plant one tree per day for the rest of his life. Over 40 years later, his untiring commitment has transformed the river island of Majuli into a green stretch, twice as big as New York's Central Park. Such a stunning achievement gave him international renown as "The Forest Man of India" and one of his country's most prestigious awards. If he's been recognized since as an inspirational model, it's mainly because he embodies a key message that resonates far beyond the Indian borders: especially in times of climate change, forest preservation is key for our entire planet.

According to a recent report by the European Forest Institute (EFI), European forests alone can remove approximately 10% of the EU's total greenhouse emissions. "They are crucial to achieving climate change mitigation because they are the only proven land-based system that removes CO₂ from the atmosphere," explains Hans Verkerk, EFI's principal scientist in the Bioeconomy programme. "Through photosynthesis, they store it in the biomass, which means in the trunks, the foliage, and the roots, and when the trees die, the carbon is transferred to the soil or into the wood products that are made with the trees once they are harvested." If by sequestering carbon, forests can therefore play a pivotal role in achieving climate neutrality by 2050, the European Commission has issued a stark warning: the sequestration rate must significantly increase by 170 metric tons of carbon dioxide equivalent per year by 2050. Yet, the available literature suggests an opposite trend, which scientists and researchers mainly blame on climate change itself.

In other words, we are basically trapped in a vicious circle: crucial for mitigating climate change, our forests are limited in unleashing such potential, as they are its victims in their turn. "Several impacts are already before our eyes, and more are expected for the next decades," explains Verkerk. "We see an increase in wildfire risk, especially in southern Europe, but also in strong winds and outbreaks of bark beetles, often combined with drought. And then we also expect changes in species distribution and productivity, which means in forests' growth pace." According to satellite-based analysis, from 1987 to 2016 drought alone caused approximately 500,000 ha of excess forest mortality. Yet, recent studies show that in the past 40 years, almost one-fifth of European forests was also affected by many other natural and so-called "anthropogenic factors". "Climate change is already significantly affecting the European forests and will keep doing so in the future," adds Verkerk. "We already have some information available, but to understand how these impacts actually take place, we need to regularly collect new, more updated, and comparable data, also by integrating field measurements, with satellite and drone information."

Monitoring the health conditions and future developments of European forests is among the aims of the ForestWard Observatory, which is currently under development within the EU-funded project Forwards. Professor of Remote sensing of Forests at the Swedish University of Agricultural Science, Ruben Valbuena is its coordinator. "We will conduct an extensive investigation on a network of areas throughout Europe," he explains. "Trees will for instance be equipped with sensors to measuring their growth rate, water availability, and so on. These data will then be crossed with satellite information on local landscape and micro-climate and thus provide precious elements to both understand the current state of our forests and predict future scenarios." Aligned with scientific research that recently suggested "forest managers and policymakers should place new adaptation strategies at the heart of practice", its final goal will be to issue appropriate recommendations to optimize forests' carbon sequestration potential.

Technically known as "mitigation activities", these actions range from reforestation to shifts in wood use and can intervene at different stages of forests' life. "Their effectiveness largely depends on the local conditions. In areas that are not subject to major disturbances, a good strategy could be to reduce the management intensity and focus on carbon storage in the trees and the soil," explains Verkerk, whose EFI is among Forwards' project partners. "On the contrary, if the effects of climate change are stronger, it's better to opt for more active management, like adapting the tree species, modifying the intensity and frequency of the forest thinning, etc." Closely followed by restoration and protection, "improved forest management" is what the report "Forest-based climate change mitigation and adaptation in Europe" identifies as the strategy providing the greatest mitigation potential. "If you're planting from scratch you can select the provenance of trees and do proper soil preparation, but at a later stage you can for instance adapt your thinning strategy and concentrate the growth on the trees that more fit your needs," adds Verkerk.

This approach involves what insiders call "Climate smart-forestry", a targeted strategy aimed at increasing climate benefits, by fostering both forests' resiliency and productivity. "First of all, sustainable forest management tries to maximize the contribution of forests to climate change mitigation," he points out. "Secondly, it aims at integrating it with adaptation measures, because adaptation measures wouldn't be effective alone. And then it also focuses on how to best use the wood of these forests in order to optimize its mitigation potential." As Valbuena explains, his project will provide a real-life experimentation ground for this strategy by setting up several "Smart forestry management pilots". "They will consist of areas, where we will for instance test new techniques of forest management, and investigate both the effects of diversification on forest resiliency, and the impact of climate change." As the project is in its early stages, the test areas have not been selected yet, but several calls for grants will soon be launched to set up forest management trials, test new measurement techniques, and many other purposes. Waiting for the ForestWard Observatory to become a reality, researchers stress the urgency of a "pan-European monitoring and reporting system of forest disturbances". Such a tool, they write in a 2022 EU-funded study, is highly needed "to develop our understanding of, and ability to respond to, disturbance dynamics."

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