Exploring Slow-Moving Landslides and Greenhouse Gas Emissions in Pre-Alpine Grassland: from Observations to Modelling

Precise estimations of greenhouse gas budgets for countries contribute to sharpened policies on the national and international level to tackle climate change. Soils pool a considerable amount of carbon and nitrogen within terrestrial ecosystems and a quarter of the Austrian terrestrial surface is dedicated to grassland. In the clay-rich Flysch zone thousands of landslides have been observed. We argue that a better understanding of mechanisms that lead to both phenomena — greenhouse gas fluxes and landslide dynamics — could provide insights into untangling the complexity of the soil carbon and nitrogen cycles and improve greenhouse gas models on active landslides.

 

To achieve this, we enrich long-term observation of the two landslides in Gresten and Hofermühle, Lower Austria with monitoring of greenhouse gas in different soils, vegetation and land use and of landslide dynamics. Employment of non-steady-state chambers with combination of comprehensive physico-chemical soil analyses, vegetation and land use surveys reveal interconnections between greenhouse gas fluxes and landslide activity. Inclusion of land displacement data gained by inclinometer measurements link our geoecological findings with in-depth landslide movements. Hydrological soil properties, such as moisture content and water-filled pore space (WFSP), impact both greenhouse gas fluxes and landslide activity the most. Additionally, slow-moving landslides alter microrelief, which consequently affects the land use management in grasslands.

 

We conclude that greenhouse gas fluxes and landslide activities not only share the common preconditionary factors, but also slow-moving landslides influence greenhouse gas fluxes indirectly. Hereby, land-use management is of crucial importance. These findings could ultimately improve current computational greenhouse gas models for territories prone to landslides and support climate policy development.