• Our new home,

    from summer 2021

  • Global Warming:

    the threat of a permafrost Carbon – climate feedback

  • We develop and improve

    stable isotopes techniques for ecological applications

  • Plants, fungi and bacteria interact

    at the root-soil interface

  • Probing the future:

    Climate Change experiments

  • Soil is fundamental to human life

  • Tropical rainforests

    hold the key to global net primary productivity

TER News

Latest publications

Long-term warming-induced trophic downgrading in the soil microbial food web

Climatic warming has been hypothesized to accelerate organic matter decomposition by soil microorganisms and thereby enhance carbon (C) release to the atmosphere. However, the long-term consequences of soil warming on belowground biota interactions are poorly understood. Here we investigate how geothermal warming by 6 °C for more than 50 years affects soil microbiota. Using metatranscriptomics we obtained comprehensive profiles of the prokaryotic, eukaryotic and viral players of the soil microbial food web. When compared to ambient soil temperature conditions, we found pronounced differences in taxa abundances within and between trophic modules of the soil food web. Specifically, we observed a ‘trophic downgrading’ at elevated temperature, with soil fauna decreasing in abundance, while predatory bacteria and viruses became relatively more abundant. We propose that the drivers for this shift are previously observed decreases in microbial biomass and soil organic carbon, and the increase in soil bulk density (decrease in soil porosity) at elevated temperature. We conclude that a trophic downgrading may have important implications for soil carbon sequestration and nutrient dynamics in a warming world.

Borg Dahl M, Söllinger A, Sigurðsson P, Janssens I, Peñuelas J, Sigurdsson BD, Richter A, Tveit AT, Urich T
2023 - Soil Biology and Biochemistry, 181: Article 109044

Phosphorus scarcity contributes to nitrogen limitation in lowland tropical rainforests

There is increasing evidence to suggest that soil nutrient availability can limit the carbon sink capacity of forests, a particularly relevant issue considering today's changing climate. This question is especially important in the tropics, where most part of the Earth's plant biomass is stored. To assess whether tropical forest growth is limited by soil nutrients and to explore N and P limitations, we analyzed stem growth and foliar elemental composition of the 5 stem widest trees per plot at two sites in French Guiana after three years of nitrogen (N), phosphorus (P), and N+P addition. We also compared the results between potential N-fixer and non-N-fixer species. We found a positive effect of N fertilization on stem growth and foliar N, as well as a positive effect of P fertilization on stem growth, foliar N, and foliar P. Potential N-fixing species had greater stem growth, greater foliar N and greater foliar P concentrations than non-N-fixers. In terms of growth, there was a negative interaction between N-fixer status, N+P, and P fertilization, but no interaction with N fertilization. Since N-fixing plants does not show to be completely N saturated, we do not anticipate N providing from N-fixing plants would supply non-N-fixers. Although the soil age hypothesis only anticipates P limitation in highly weathered systems, our results for stem growth and foliar elemental composition indicate the existence of considerable N and P co-limitation, which is alleviated in N-fixing plants. The evidence suggests that certain mechanisms invest in N to obtain the scarce P through soil phosphatases, which potentially contributes to the N limitation detected by this study.

Vallicrosa H, Lugli LF, Fuchslueger L, Sardans J, Ramírez-Rojas I, Verbruggen E, Grau O, Bréchet L, Peguero G, Van Langenhove L, Verryckt LT, Terrer C, Llusià J, Ogaya R, Márquez L, Roc-Fernández P, Janssens I, Peñuelas J
2023 - Ecology, Article e4049

Close coupling of plant functional types with soil microbial community composition drives soil carbon and nutrient cycling in tundra heath

Aims

This study aimed at elucidating divergent effects of two dominant plant functional types (PFTs) in tundra heath, dwarf shrubs and mosses, on soil microbial processes and soil carbon (C) and nutrient availability, and thereby to enhance our understanding of the complex interactions between PFTs, soil microbes and soil functioning.

Methods

Samples of organic soil were collected under three dwarf shrub species (of distinct mycorrhizal association and life form) and three moss species in early and late growing season. We analysed soil C and nutrient pools, extracellular enzyme activities and phospholipid fatty acid profiles, together with a range of plant traits, soil and abiotic site characteristics.

Results

Shrub soils were characterised by high microbial biomass C and phosphorus and phosphatase activity, which was linked with a fungal-dominated microbial community, while moss soils were characterised by high soil nitrogen availability, peptidase and peroxidase activity associated with a bacterial-dominated microbial community. The variation in soil microbial community structure was explained by mycorrhizal association, root morphology, litter and soil organic matter quality and soil pH-value. Furthermore, we found that the seasonal variation in microbial biomass and enzyme activities over the growing season, likely driven by plant belowground C allocation, was most pronounced under the tallest shrub Betula nana.

Conclusion

Our study demonstrates a close coupling of PFTs with soil microbial communities, microbial decomposition processes and soil nutrient availability in tundra heath, which suggests potential strong impacts of global change-induced shifts in plant community composition on carbon and nutrient cycling in high-latitude ecosystems.

Koranda M, Rinnan R, Michelsen A
2023 - Plant and soil, in press

Lecture series

Microbial ecology of nitrogen cycling in paddy soils

Yong-Guan Zhu
Research Centre for Eco-Environmental Sciences & Institute of Urban Environment, Chinese Academy of Sciences
27.06.2019
09:00 h
Lecture Hall HS 5, UZA2 (Geocentre), Althanstrasse 14, 1090 Vienna

How to meet the Paris 2°C target: Which are the main constraints that will need to be overcome?

Ivan Janssens
Centre of Excellence of Global Change Ecology, University of Antwerp, Belgium
15.11.2018
12:00 h
Lecture Hall HS2 (UZA 1), Althanstraße 14, 1090 Vienna

Soil C dynamics –when are microbial communities in control?

Naoise Nunan
Institute of Ecology and Environmental Sciences IEES Paris, France
25.10.2018
12:00 h
Lecture Hall HS2 (UZA 1), Althanstraße 14, 1090 Vienna