Revegetation measures improve soil aggregate stability: a case study of a landslide area in Central Switzerland

Bern

2009

S. 45-60

6 Abb., 5 Tab., zahlr. Lit. Ang.

Unselbständiges Werk

200159823

In soil bioengineering, revegetation measures are applied to improve soil structure and to protect the soil against erosion and shallow landslides. Soil aggregation processes play a crucial role in re-establishing soil structure and function. The objective of this study was to determine whether soil aggregate stability increased along with soil and vegetation development in a landslide area that was stabilised with soil bioengineering measures. Three adjacent sites were compared with regard to soil aggregate stability: i) a gully with combined technical and biological stabilisation measures dating back 25 years (revegetated site), ii) a gully with only technical stabilisation measures of the same age (control site), and iii) a climax forest stand (climax forest site). On the revegetated site, the soil aggregate stability was significantly higher than on the control site, approaching the values of the climax forest. The revegetated site was characterized by a dense stand of bushes, whereas on the control site, only sparse pioneer vegetation had established spontaneously. Data suggest that revegetation measures increased soil aggregate stability by substantially accelerating vegetation development and by promoting soil formation processes such as accumulation of fine soil particles, organic matter and mycorrhizal propagules.