Short- and long-term feedback between vegetation and morphodynamic processes and climate warming

• Applicant: Privatdozent Dr. Erich Tasser
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 394200609

Extensive research has already been carried out within the framework of the 1st period of SEHAG to demonstrate how cryospheric changes influence colonisation in the glacier foreland, which interaction exists between vegetation, soil and geomorphological/hydrological disturbances, and how climate change is affecting these processes. The results achieved so far are promising: We demonstrated that vegetation establishment is significantly slower on disturbed sites than on stable sites. The plant trait composition and species diversity are mainly driven by time since deglaciation, elevation, inclination and length of growing season, but there are also some interaction effects between vegetation and soil. Soil organic matter content, total dissolved nitrogen and carbon are significantly correlated with vegetation cover and species number. Further important findings will follow by the end of 2021. Based on these results, the 2nd phase will be to analyse the underlying processes in detail and to forecast the developments into the future (time steps of 10 years starting with 2030 and ending with 2050). We will test in the 2nd phase: a) if a specific succession and specific functional plant responses exist along chronosequences or whether they differ between different sites and if so, why; b) if disturbances facilitate habitat shifts as a result of migrating species from the surrounding area especially of species with low seed weight; and c) if climate change is the only driver of historical vegetation changes or whether land use plays a significant role in lower belts. To answer the first objective, we will use our data basis from the three study areas to determine the significant drivers and the underlying functions. Then we will validate and generalise these relationships by integrating time series of vegetation development from further glacier foreland areas in Tyrol and South Tyrol. The modelling results will be used for forecasting in the future. The second objective we will answer by focusing on the feedback of single species/families, plant traits and functional groups to disturbance events. The main question here is whether there is a standardised succession with pioneer-, early- and late successional species or whether the succession process is influenced by seed bank and/or by vegetative or generative sprouting of species from the surrounding area. We will also investigate what level of species and functional diversity matters for stability. For the third objective we will develop temporally and spatially explicit models of species dynamics depending on environmental factors and disturbances. We will disentangle potential developments that will be triggered due to climate change and land use change by concentrating on the development of process-oriented indicator species/functional traits. By means of multivariate analyses, changes will be parameterised for the spatially explicit forecasting of the vegetation distribution.

• DFG Programme: Research Units
• Subproject of: FOR 2793: Sensitivity of High Alpine Geosystems to Climate Change Since 1850 (SEHAG)
• International Connection: Italy
• Partner Organisation: Autonome Provinz Bozen - Südtirol