Czech scientists: forests store carbon in the soil — but only if the forests themselves survive

Czech researchers from the Forestry and Game Management Research Institute, working together with colleagues from the Czech University of Life Sciences and the Institute for Forest Ecosystem Research, have studied how forest soils accumulate carbon — and why this function of the forest depends directly on its ability to survive in a changing climate.

According to the scientists, only about half of all CO₂ released into the atmosphere actually stays there — the other half is absorbed by natural "reservoirs" on land and in the ocean. On land, forests play a major role in this process, absorbing carbon dioxide through photosynthesis.

Experts stress that forest soil is not simply a storage tank for CO₂. The organic content of soil boosts its ability to retain water, particularly on sandy ground, which makes forests more resilient to drought, reduces flood risk and helps stabilise the local microclimate. Organic matter also strengthens soil structure, making it more resistant to erosion.

As the researchers note, the presence of a healthy topsoil layer turns out to matter even more than canopy closure: removing the topsoil can increase erosion by a factor of 10 to 100, whereas felling trees without disturbing the soil raises erosion by only a few tens of percent.

Carbon in the soil also serves as a source of energy and nutrients for soil organisms, and its reserves can be used as an indicator of biodiversity. According to the study's authors, the greatest threat to soil carbon stocks comes not so much from forestry practices themselves as from large-scale disasters — fires, windthrow and pest outbreaks — which can wipe out the tree canopy on a massive scale.

The forest's ability to absorb carbon is now regarded in Czechia as one of the key ecosystem services, though a financing mechanism for this function has yet to be developed. One proposed solution is so-called offset (compensation) projects, which are currently applied only to above-ground forest biomass, as it is easier to measure precisely. Bringing forest soils into the carbon offset system will require further research and monitoring, including as part of the forthcoming EU directive on soil monitoring and resilience.

One of the first voluntary offset projects in Czechia has already been carried out by Lesy Colloredo-Mannsfeld. According to the scientists, projects focused on improved forest management (IFM) hold the greatest potential in the country, having already proven effective at increasing carbon stocks. Such initiatives could reduce state spending on adapting forestry to climate change, if funding is partly taken on by industrial companies, developers or the banking sector.

The researchers name natural forest regeneration — provided wild game pressure is significantly reduced — along with gentler management methods and a gradual shift toward mixed, multi-aged stands resilient to climate extremes, as key conditions for adapting Czech forests to climate change. The scientists' central conclusion is simple: a forest that fails to survive climate change will not preserve its stored carbon either — the resilience and vitality of forest stands take priority over all of the forest's other functions.

Around Prague, based on reporting by ekolist.cz