Rock-plant interactions driving early soil development and landscape evolution

PIs: 

• Katarina Donstova, Environmental Science, UArizona
• Katrina Dlugosch, Ecology and Evolutionary Biology, UArizona
• Scott Saleska, Ecology and Evolutionary Biology, UArizona
• Samuel Abiven, CEREEP-Ecotron Ile De France and Département de Géosciences, Ecole Normale Supérieure (ENS), Université Paris Sciences & Lettres (PSL)

The interaction between abiotic and biological processes is crucial to understand the development of life on Earth and the ecosystem services. Natural highly heterogeneous landscapes that support life develop through biological and abiotic processes at the interface of atmosphere, hydrosphere, and lithosphere. Despite their importance to natural ecosystems and humanity, we still lack good understanding of the mechanisms of landscape formation. Deeper understanding of ecosystem services such as primary production and regulation of nutrient and water cycles can be gained if initial stages of soil and landscape formation are examined when the system is relatively simple. The University of Arizona’s Landscape Evolution Observatory (LEO) at Biosphere 2 and the Ecotron Ile de France developed by the CNRS at ENS-PSL, are unique and complementary tools used in this project for examining interaction of soils and plant communities and their physical/biological processes at landscape scales on LEO, and in precisely controllable environments with high replication at the Ecotron.

This project uses LEO and the Ecotron to investigate the process of plant colonization on a bare landscape and the effects of the newly introduced plants on weathering (increasing CO₂ in soils, exuding organic acids, and modifying fluxes of water and solutes), hydrological dynamics and overall C cycling. To determine how plant establishment and community composition is influenced by position and traits of plants, microbial symbionts, and further feeds back to influence ecosystem and landscape development this project has a two-pronged effort: a) large-scale vegetation experiments on the LEO hillslopes and b) complementary process scale mesocosm experiments to be performed at the Ecotron. 

The project involves two graduate students funded by the IRC program, who work in parallel, one focused on LEO, the other at the Ecotron. The project enhances the synergies between B2 and the Ecotron: together they provide a unique capability for bridging scales in studying soil and landscape formation as influenced by plant traits; continues to build the strategic collaboration between the two institutions; and engages graduate students as critical members of the research collaboration.