Soil microorganisms and plants are key players in the production and breakdown of organic matter, and together control global biogeochemical cycles of carbon, nitrogen and phosphorus. TER, the Division of Terrestrial Ecosystem Research, aims to advance our fundamental understanding of how plants and soil microorganisms respond to, and in turn shape, their abiotic and biotic environment, and to determine the consequences for the functioning of Earth’s ecosystems.
Research Mission
Primarily dedicated to basic research, TER addresses pressing environmental issues, such as the impact of climate and land-use change on ecosystem functioning and the role of soils in the global carbon cycle and in food security. In doing so, we work on scales from µm (i.e. the scale at which microbes operate) to the biosphere (i.e. where plant and microbial processes become evident), and in ecosystems spanning the Arctic tundra to tropical rainforests. We integrate this scale of thinking with state-of-the-art methods, including stable isotope tracing and biomarker fingerprinting, and are developing novel approaches to estimate gross environmental processes with isotope pool dilution techniques.
We are strongly committed to conduct world-leading research in a motivating and intellectually stimulating environment, and to train our students to become independent and internationally competitive scientists who enjoy research and contribute to society as conscientious citizens.
Research Projects
SEACUE - Seasonal dynamics of soil microbial carbon sequestration
Rising air temperatures caused by increasing CO2 concentrations in the atmosphere call for efficient counteractive strategies. One strategy is the transfer of carbon (C) into soil where it can be stabilized.
The majority of C in soils is remains of dead microbial biomass. A first step to transfer C into stabile soil pool is thus the efficient uptake of C into soil microorganisms. Carbon-use-efficiency describes how much of the C that microbes take up is used for microbial growth and how much is respired. After cell death microbial compounds can get attached to clay minerals in the soil and become stabilized. Up to now, there is little direct evidence for a connection of carbon-use-efficiency, sorption on minerals, and persistence of C in soils. Furthermore, little is known about how temperature, nutrient availability, substrate chemistry, and adaptations of the active microbial community influence carbon-use-efficiency. Since these factors vary seasonally in temperate systems, the interactions of controls could result in seasonal variations of carbon-use-efficiency. Well timed amendments to soils at times of high carbon-use-efficiency, might lead to accumulation of stabile soil C and could counteract climate change.
In this project we will, for the first time, measure carbon-use-efficiency in a temperate forest and an agricultural field, both with or without litter incorporation in fall, 18 times over the course of two years. We will use this data of carbon-use-efficiency, nutrient availability, substrate chemistry, temperature and microbial community composition to statistically determine the importance of direct and indirect controls on carbon-use-efficiency. We will further set up short term laboratory experiments addressing microbial adjustments to temperature, nutrient availability, and substrate chemistry. To investigate the connection of carbon-use-efficiency and stabilization of C on clay minerals we will set up another laboratory incubation experiment. In this experiment we will add labelled substances to soils taken at times of high and low carbon-use-efficiency and we will trace the uptake of the label by the soil microbes and the transfer into the different soil C pools over time. To assess the long term persistence of C in dependence of timing and nature of substrate amendments we will use a mathematical soil C model.
To our knowledge this is the first project to investigate the seasonality carbon-use-efficiency and the importance and interactions of environmental factors and the microbial community. The combination of field and laboratory experiments as well as modeling approaches will clarify the role of carbon-use-efficiency in the formation of stabile soil C. Our findings will eventually help to develop temporally accurate management practices to counteract climate change.
Cooperation partners:
- Andreas Richter, University of Vienna (18O CUE method)
- Bruce Hungate, Northern Arizona University, USA (q-SIP analysis)
- Stuart Grandy and Emily Kyker-Snowman, University of New Hampshire, USA (microbial modelling)
- Sophie Zechmeister-Boltenstern, University of Natural Resources and Life Science, Vienna (forest site and litter removal experiment)
- Heide Spiegel and Taru Sandén, Austrian Agency for Health and Food Safety (field site and crop residual removal experiment)
Investigated by:
- Jörg Schnecker