Monitoring soil organic carbon in forests and grasslands

Soil contains vast amounts of carbon. The amount of carbon stored in the soil in boreal forests is greater than that which is stored in trees and other vegetation. Changes in these vast stores are affected by climate change and also by the management of forested land. However, the measurements of soil organic carbon (SOC) are often subject to high uncertainties, and there are no historic data that describe the development in Norwegian SOC stores over time.

Annen prøve-sidetoppp
Photo: O. Janne Kjønaas

The complexity of measuring actual SOC storage and the lack of data create major challenges in relation to both the calculation and reporting of Norway’s national greenhouse gas emissions to the UN’s Framework Convention on Climate Change (UNFCCC) and for projections of the forests’ emissions and absorption of CO2.

For this reason, a programme for nationwide monitoring of SOC in forests and grasslands is being set up in 2022. Field workers from the Norwegian National Forest Inventory (NFI) will visit a selection of NFI sample plots annually and take soil samples. Two samples will be taken from all of the selected plots over a period of 20 years. The soil samples that are collected will give us information about the levels of, and changes in, the soil carbon stores in Norwegian forests and grasslands.

The Norwegian Ministry of Agriculture and Food is funding the national programme for monitoring SOC in forests and intensive grasslands, and soil sampling is expected to begin in spring 2023.