Harmonised dataset of organic carbon stock estimates in European forest soils over three decades

This dataset provides harmonised estimates of organic carbon (OC) stocks in European forest soils at the plot and survey-year level, calculated to depths of 100 cm and 30 cm, with associated uncertainties. The estimates are based on soil data from the ICP Forests programme, collected at roughly 10-year intervals since the late 1980s within both the systematic Level I ("s1" survey; approximately 6000 plots on a 16 x 16 km grid) and intensive Level II ("so" survey; approximately 600 plots) networks. Calculations were performed by ICP Forests' Forest Soil Coordinating Centre (FSCC) within the Horizon Europe PathFinder project, using an enhanced version of the data* reported by individual countries and stored in the centralised database of the Programme Coordinating Centre of ICP Forests. The methodology for stock calculations largely follows De Vos et al. (2015), while the methodology for soil sampling and analysis follows different versions of ICP Forests manual "Part X Sampling and analysis of soil".

The dataset also includes harmonised metadata (stratifiers) such as the WRB Reference Soil Group, highest-tier humus form, European Forest Type Category and biogeographical region. Stock data derived from both fixed-depth layers ("som") and pedogenic horizons ("pfh") are available. Plausibility filters, indicating which stock estimates are considered plausible by FSCC, are included and their use is highly recommended.

* ICP Forests soil data - Upon request, all underlying soil data, as well as data from other forest ecosystem surveys, are available through the Programme Coordinating Centre of ICP Forests. Data can be requested by submitting a data request form, as outlined on the ICP Forests website.

Files
Organic carbon stock data in this deposit are organised per survey level (.csv file), plot (column plot_id), survey year (column survey_year) and sampling approach (column survey_form).

attribute_catalogue_stocks.txt - Description of field names used in the .csv files
level_one_s1_soil_oc_stocks.csv - Forest soil organic carbon stocks and metadata for the systematic Level I network
level_two_so_soil_oc_stocks.csv - Forest soil organic carbon stocks and metadata for the intensive Level II network
Acknowledgements
The research leading to these results has received funding from the European Union Horizon Europe (HORIZON) Research & Innovation programme under the Grant Agreement no. 101056907. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Climate, Infrastructure and Environment Executive Agency (CINEA). Neither the European Union nor the granting authority can be held responsible for them.

The evaluation was based on data that was collected by partners of the official UNECE ICP Forests Network. Data collection was mainly funded by national bodies and part of the data was co-financed by the European Commission.

Institutions involved in the soil data collection: Austrian Research Centre for Forests (BFW) (Austria), SPW ARNE – Départment de l’Etude du milieu Naturel et Agricole (Belgium), Université catholique de Louvain (Belgium), Research Institute for Nature and Forest (INBO) (Belgium), Executive Environment Agency at the Ministry of Environment and Water (Bulgaria), Croatian Forest Research Institute (Croatia), Ministry of Agriculture, Rural Development and Environment (Cyprus), Forestry and Game Management Research Institute (FGMRI) (Czechia), University of Copenhagen (Denmark), Estonian Environment Agency (EEIC) (Estonia), Natural Resources Institute Finland (LUKE) (Finland), Ministère de l‘Agriculture, de l’Agroalimentaire et de la Forêt (France), Office National des Forêts (France), Bundesministerium für Ernährung und Landwirtschaft (BMEL) (Germany), Institute of Mediterranean Forest Ecosystems (Greece), National Land Centre (Hungary), University of Sopron (Hungary), University College Dublin (UCD) (Ireland), Comando Unità Tutela Forestale, Ambientale e Agroalimentare Carabinieri (Italy), Latvian State Forest Research Institute „Silava” (Latvia), Lithuania State Forest Service (Lithuania), Ministère de l’Environnement, du Climat et du Développement durable (Luxembourg), National Institute for Public Health and Environment RIVM (Netherlands), Norwegian Institute of Bioeconomy Research (NIBIO) (Norway), Forest Research Institute (Poland), Instituto da Conservação de Natureza e das Florestas (ICNF) (Portugal), National Institute for Research and Development in Forestry “Marin Drăcea” (INCDS) (Romania), Institute of Forestry (Serbia), National Forest Centre - Forest Research Institute (Slovakia), Slovenian Forestry Institute (SFI) (Slovenia), Ministry for the Ecological Transition and the Demographic Challenge (Spain), Swedish University of Agricultural Sciences (Sweden), Swiss Federal Research Institute WSL (Switzerland), Centre for Forest Management – Forest Research (United Kingdom)

ersion v2_20250807_20241213