Thomas C. Wagner

My research focuses primarily on how plant species or plant communities can establish themselves and thrive in a dynamic environment characterized by frequent disturbances or environmental uncertainties.

Originally, my focus was on the establishment and spread herbaceous plants in arid african savannas, with sporadic and highly variable rainfall, fire, and varying degrees of grazing. But recently, I have concentrated on an ecosystem that is archetypal for dynamic environments: Alpine rivers.

Alpine rivers are highly dynamic ecosystems characterized by continuous disturbances. Regular flooding and the associated transport of sediments and bedload turnover create an everchanging mosaic of aquatic and terrestrial habitats, each with very different characteristics, abiotic conditions, or in different stages of succession, supporting a highly divers fauna and flora.

Frequent flooding and hydrodynamics, bedload turnover but also the nutrient poor, largely open and exposed gravel bars with substrates of varying coarseness, different water capacity and strongly fluctuating moisture level pose a number of major challenges especially for immobile plants, even under natural conditions.

Here, I am investigating how individual plant species and typical plant communities can establish themselves and survive in this unstable environment of Alpine river corridors. To this end, I am examining the underlying ecosystem processes such as hydrodynamics, bedload transport or plant dispersal, and I am modeling the spatiotemporal configuration of the habitat situation. In addition, I am also investigating the relationship between sediment and vegetation dynamics in alpine alluvial fans in the upper catchment area of these rivers and their role as primary habitats for many Alpine river species.

My study sites include the Upper Isar River, the Tyrolean Lech, the Linder-Ammer-System in the Northern Alps and the Tagliamento, Piave, Celina, Meduna and Isonzo catchments in the South-Eastern Alps.

Follow me on BlueSky: https://bsky.app/profile/tcwagner.org