Biodiversity and Soil Stability
How does plant diversity affect soil aggregate stability and surface erosion in disturbed alpine ecosystems?
Machine-graded ski pistes are often subject to erosion in steep terrain above treeline, and a species-rich vegetation may play a key role in preventing erosion. A research project of the WSL and the University of Basel investigates therefore the relationship between plant diversity and soil stability parameters (aggregate stability and surface erosion) at disturbed high alpine sites.
Research questions
- Is soil aggregate stability positively correlated with plant species richness?
- Is surface erosion decreased with higher plant functional diversity?
- What are potential root properties that could explain mechanisms for the positive effect of plant diversity on soil properties?
Methods
- aggregate stability tests of soil from ski slopes and analyses of relationships between aggregate stability, root traits and plant diversity,
- rainfall experiments on a machine-graded ski piste and analyses of the influence of vegetation cover and plant functional diversity on surface erosion and
- analyses of root traits of 13 alpine pioneer species from a ski piste.
Results
- Soil aggregate stability was positively correlated with plant species richness.
- Surface erosion was decreased with higher plant functional diversity. Graminoids were the most efficient group.
- A high diversity of belowground growth forms is the most likely mechanism for the positive effect of plant diversity on soil properties.
- Diese Untersuchungen unterstreichen, wie wichtig eine hohe Pflanzendiversität für den Erosionsschutz von gestörten alpinen Flächen ist.
Project details
Project duration
2008 - 2011