The EU is currently working on a soil monitoring law with the objectives of safeguarding soil health, establishing sufficiently extensive and frequent soil monitoring and promoting sustainable farming and forest management practices for soil health.

It is important to ensure that the new law takes into account the specific characteristics of forest soils and national monitoring frameworks incl. National Forest Inventories.

Forest soils differ significantly from agricultural soils in terms of their physical, chemical, and biogeochemical properties. Therefore, indicators and threshold values that take into account the specific characteristics of forest soils are needed in the implementation of soil monitoring law. The indicators and tresholds should be defined on the basis of existing forest soil monitoring data, such as ICP Forest data.

Soil monitoring of forests should be carried out in conjunction with tree surveys and the national forest inventory, so that information on both vegetation and soil conditions can be combined.

In addition to the soil monitoring law, the EU is promoting cooperation between different actors and the use of research knowledge by setting up 100 research areas (Living Labs) to develop farming and forestry practices that promote soil health.

The research site in Asikkala, used by the EU-funded and Luke coordinated HoliSoils project, is one of the research areas proposed for the EU programme. Among other things, greenhouse gas exchange, energy balances, water balance, soil properties and microbiota, tree growth, understory vegetation and other species of the soil and the ecosystem as a whole are measured there.

HoliSoils researchers have supported the preparation of the soil monitoring law by providing information on monitoring methods and assessing the suitability of the proposed law for forest soil monitoring. Previous European-wide forest soil monitoring programmes have developed well-established and harmonised sampling methods that can be applied to the new monitoring.

In addition, the HoliSoils project has developed sampling guidelines and analytical methods to help harmonise soil monitoring.

The HoliSoils and another EU-funded project, Benchmarks, have analysed the suitability of the soil carbon loss indicator mentioned in the proposed law for monitoring soil health. The proposed indicator is not suitable as such for all European forest and arable lands and its use could lead to inconsistent results with measured or modelled carbon stock changes that are reported by the national greenhouse gas inventories and used under the LULUCF regulation. Based on a single measurement and a simple indicator, it is not possible to draw conclusions on soil carbon loss.

A method based on repeated soil sampling is needed to monitor changes in carbon stocks, as is already in use e.g. in Sweden and feasible in Finland.

Of the current forest management practices in Finland, the drainage and clear-cutting of peatland forests are particularly challenging for the soil, as they result in the water nutrient loading and high greenhouse gas emissions from rapidly decomposing peat layer.

The HoliSoils project is looking for more sustainable solutions for timber production in peatland forests by testing the soil effects of selection cutting as part of continuous cover forestry and clear-cutting. The studies have shown that silviculture with selection cutting avoids the high climate emissions and water nutrient loading caused by clear-cutting. Maintaining tree cover on peatland forests avoids the need for drainage and allows the water balance of the peatland to return closer to its original condition.