At the University of Arizona, we are building a program to bridge the gap between laboratory- and field-scale studies by utilizing the unique infrastructure of Biosphere 2. Biosphere 2 offers unique opportunities for the exploration of complex questions in Earth sciences because of its ability to combine varying scales, precise manipulation and fine monitoring in controlled experiments. By building upon the large external scientific network at the University of Arizona in hydrology, geology, geochemistry, ecology, biology, physics, engineering and atmospheric sciences, we are developing a strong multidisciplinary team of researchers who are undertaking the design and deployment of top-notch science to address complex questions in environmental sciences. Projects for 2020 REU students include:
Ecosystem Science, Renewable Energy Production, Food, and Water Sustainability
Greg Barron-Gafford, Department of Geography and Development, and Biosphere 2. External forces (like environmental and human factors) and internal characteristics (like plant ecophysiology) determine where species can live and thrive. This nexus is critical for tackling one of the greatest challenges facing our future - how to simultaneously maximize renewable energy production and food production without degrading the environment. The "Agrivoltaics" installation at B2 blends renewable energy production from solar photovoltaics with agriculture to study the impacts of this novel approach on plant function, water use, and biomass production.
Mineral Weathering, Soil Formation and Carbon Sequestration as Influenced by Water Flow and Biota
Katerina Dontsova, Biosphere 2. Projects at B2 would focus on soil formation processes and development of subsurface heterogeneity through hydrologic-geochemical coupling using direct measurement and geochemical modelling: what happens in the basalt covering LEO slopes as a result of water flow and biological activity; what is the role of slope position, water residence time, and microbial activity on total weathering, chemical denudation, formation of high surface-area secondary solids, and accumulation of organic and inorganic carbon.
Microbes as the engineers of the soil, plants, and atmosphere of Biosphere 2
Laura Meredith, School of Natural Resources and Environment. How do microbes survive and thrive in diverse biomes and different ecosystem compartments including water, soils, the surface and interior of leaves, and air? How do differences in the microbiomes of different ecosystem compartments highlight their ability to affect the biosphere, and specifically, its atmosphere? Our research explores how microbial communities in the Tropical Rainforest and the Landscape Evolution Observatory affect atmospheric composition by their production and consumption of trace gases that affect climate and air quality. The student(s) involved in this project will have the opportunity to learn methods in microbial genomics, bioinformatics, and analytical atmospheric chemistry and contribute to key preparations for an international research campaign in the Tropical Rainforest.
Developing, Improving, and Testing a Computer-based, Terrestrial Integrated Modeling System (TIMS)
Guo-Yue Niu, Department of Hydrology & Atmospheric Sciences, and Biosphere 2. TIMS focuses specifically on the interaction between hydrological, microbial, geochemical, geomorphological and ecological processes at the Earth’s land surface. TIMS takes advantage of existing state-of-the-art community models (e.g., CATHY and Noah-MP) and couples states and fluxes between the models to study interaction and feedback. TIMS is being developed using an experimentation-model learning cycle, so that new data derived from B2 physical models, e.g., LEO and the rainforest, can help us improve our understanding and parameterizing of fundamental processes.
Water Transit Time at Catchment Scales
Peter Troch, Department of Hydrology & Atmospheric Sciences, and Biosphere 2 (Science Director). Troch studies catchment scale hydrological processes via advanced measurement, modeling and synthesis to 1) Develop, test, and apply advanced observation methods for hydrological fluxes and states at a range of spatial and temporal scales; 2) Develop hillslope-to-catchment scale hydrological models for water and solute transport; 3) Understand hydrological synthesis at the catchment scale with special attention to extremes; 4) Determine effect of scale on co-evolution of hydrological and geochemical processes. Findings contribute to improved water resources management in light of climate change and other human influences. Students can work on water transit time estimation using stable isotope data from rain and streamflow samples combined with field and lab work including running the laser spec, and mathematical modeling of flow and transport processes at catchment scales using both LEO and CZO watersheds.
Tropical Forest Dynamics and Trace Gas Fluxes
Joost van Haren, Biosphere 2. Tropical forests are among the most dynamic ecosystems in the world, but their responses to climate change are uncertain. B2 provides an opportunity to study tropical ecosystems under future conditions (increased temperature, decreased precipitation); the large enclosure and artificial rainfall allows precise determination of water and carbon movement through the biome. Students use the B2 tropical forest to assess plant, hydrological, and carbon cycling responses to altered temperature and precipitation.
Hydrologic Flow and Transport at Hillslope Scales
Minseok Kim and Peter Troch, Biosphere 2. Tracing (isotopically or chemically) ‘tagged’ water particles help us understand flow pathways inside a hydrologic system. The Landscape Evolution Observatory (LEO) hillslopes at Biosphere 2 provide us unique opportunities to conduct experiments with tagged water particles and to monitor those movements inside the hillslope at the unprecedented spatio-temporal resolution. We use the experimental data to develop and to test hypotheses, theories, and models. Students involved in this project will have opportunities to learn how we conduct experiments and monitor the hillslopes; to analyze isotopic composition and chemistry of water samples that collected at the LEO hillslopes; to learn hydrologic flow and transport theories and models.