How does edaphic context affect soil organic matter persistence?

European and Flemish climate-change policies aim to enhance carbon (C) storage in soils of conservation areas, including natural areas such as forests, grasslands and wetlands. Soil capability and condition however may impact C persistence and material cycles in soils, and therefore the sustainability of this policy effort, by making soil C stocks more vulnerable to climatic anomalies, shocks and disturbances. Edaphic limitations in terms of nutrients, acidity, temperature or moisture availability have been shown to affect soil C persistence, but processes behind this effect remain elusive and poorly quantified.

In this contribution, we therefore present several case studies in western European forests and wetlands, where we assess how the molecular composition of several soil organic matter fractions varies along gradients of soil cover, edaphic conditions and perturbation intensity. Furthermore, by comparing different fractions and markers, we evaluate the suitability of different methods to evaluate changes in soil carbon dynamics, as a tool to predict the potential impact of anthropogenic stresses and management interventions on soil carbon persistence.