Menichetti, Lorenzo
- Department of Ecology, Swedish University of Agricultural Sciences
- Natural Resources Institute Finland (LUKE)
The utilisation of forest resources is frequently criticised for its adverse environmental impacts. In particular, the widespread use of rotation forestry practices, including clear-cutting, is viewed as a threat to ecosystems. Clear-cutting has short-term impacts that turn the forest into a net carbon (C) source, but such modifications to the ecosystem also have long-term effects. Any analyses of alternative management approaches should include at least one full rotation, which requires model extrapolations. In this study, we used data from a well-documented series of long-term forest monitoring sites in Finland (ICP Forests Level II), focusing on two recent clear-cut sites-one dominated by Scots pine and the other by Norway spruce. These data were utilised to constrain a soil C model and to extrapolate two future scenarios: rotation forestry and set-aside (unmanaged). We simulated these scenarios over a period exceeding one full rotation and compared the outcomes. Although the stand thinning events did not heavily affect the C balance of the studied sites, clear-cutting did. Each clear-cut event caused a negative soil organic carbon (SOC) balance for many decades. It took between 37 and 69 years (for Norway spruce and Scots pine, respectively) to reach a break-even point in which soil C losses compensated for C uptake. Emissions from coarse harvest residuals represented the greatest C source after clear-cutting, followed by fine roots and then foliage. When comparing such a scenario with a set-aside scenario, the soil C budget of the managed stand after clear-cut was negative until the first thinning or even until the following clear-cut, while the set-aside was always a C sink in soil. Thus, scenario analyses of forest C sequestration that disregard long-term soil C dynamics following management interventions may lead to biased conclusions. As a management regime, rotation forestry was relatively ineffective when evaluated considering C sequestration as an important ecosystem service.
C fluxes; C sequestration; clear-cutting; forest management; long-term modelling; rotation forestry
European Journal of Soil Science
2025, volume: 76, number: 4, article number: e70154
Publisher: WILEY
Soil Science
Forest Science
https://res.slu.se/id/publ/142982