• 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

  • Dr. Alexander Tveit


    Dr. Alexander Tveit (Arctic University of Norway, Tromsø) has been awarded a grant from the Research Council for his project ’Time & Energy: Fundamental microbial mechanisms that control CH4 dynamics ...

  • First Soil Ecology Workshop at DMES


    Students and scientists of the DMES who are working in the field of soil microbial ecology and biogeochemistry met on May 20th for the first DMES Soil Ecology Workshop. This ...

  • Summer Research Experience @ TER


    Three positions are available for Masters students during the summer 2016, that will provide a unique opportunity to participate in one of the research projects and become member of the ...

  • MSc. Judith Braun



    Judith Braun successfully defended her Master thesis entitled „Getting to the bottom of 15N Isotope Pool Dilution technique - Gross N Mineralization revisited".
    Excellent, Judith!

Latest publications

Nitrogen isotope fractionation during N uptake via arbuscular mycorrhizal and ectomycorrhizal fungi into grey alder

Arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi affect plant nitrogen (N) dynamics. Plant
N isotope patterns have been used to characterise the contribution of ECM fungi to plant N uptake. By
quantifying and comparing the effects of an AM and an ECM fungus on growth, N uptake and isotopic
composition of one host plant grown at different relative N supply levels, the aim of this study was to
improve the mechanistic understanding of natural 15N abundance patterns in mycorrhizal plants and
their underlying causes.
Grey alders were inoculated with one ECM fungus or one AM fungus or left non-mycorrhizal. Plants
were grown under semi-hydroponic conditions and were supplied with three rates of relative N supply
ranging from deficient to luxurious.
Neither mycorrhizal fungus increased plant growth or N uptake. AM root colonisation had no effect
on whole plant 15N and decreased foliar 15N only under N deficiency. The roots of these plants were
15N-enriched. ECM root colonisation consistently decreased foliar and whole plant 15N.
It is concluded, that both mycorrhizal fungi contributed to plant N uptake into the shoot. Nitrogen
isotope fractionation during N assimilation and transformations in fungal mycelia is suggested to have
resulted in plants receiving 15N-depleted N via the mycorrhizal uptake pathways. Negative mycorrhizal
growth effects are explained by symbiotic resource trade on carbon and N and decreased direct plant N
© 2016 Elsevier GmbH. All rights reserved.

2016 - Journal of Plant Physiology, 205: 84-92

Little effects on soil organic matter chemistry of density fractions after seven years of forest soil warming

Rising temperatures enhance microbial decomposition of soil organic matter (SOM) and thereby increase the soil CO2 efflux. Elevated decomposition rates might differently affect distinct SOM pools, depending on their stability and accessibility. Soil fractions derived from density fractionation have been suggested to represent SOM pools with different turnover times and stability against microbial decomposition.

To investigate the effect of soil warming on functionally different soil organic matter pools, we here investigated the chemical and isotopic composition of bulk soil and three density fractions (free particulate organic matter, fPOM; occluded particulate organic matter, oPOM; and mineral associated organic matter, MaOM) of a C-rich soil from a long-term warming experiment in a spruce forest in the Austrian Alps. At the time of sampling, the soil in this experiment had been warmed during the snow-free period for seven consecutive years. During that time no thermal adaptation of the microbial community could be identified and CO2 release from the soil continued to be elevated by the warming treatment. Our results, which included organic carbon content, total nitrogen content, δ13C, Δ14C, δ15N and the chemical composition, identified by pyrolysis-GC/MS, showed no significant differences in bulk soil between warming treatment and control. Surprisingly, the differences in the three density fractions were mostly small and the direction of warming induced change was variable with fraction and soil depth. Warming led to reduced N content in topsoil oPOM and subsoil fPOM and to reduced relative abundance of N-bearing compounds in subsoil MaOM. Further, warming increased the δ13C of MaOM at both sampling depths, reduced the relative abundance of carbohydrates while it increased the relative abundance of lignins in subsoil oPOM. As the size of the functionally different SOM pools did not significantly change, we assume that the few and small modifications in SOM chemistry result from an interplay of enhanced microbial decomposition of SOM and increased root litter input in the warmed plots. Overall, stable functional SOM pool sizes indicate that soil warming had similarly affected easily decomposable and stabilized SOM of this C-rich forest soil.

Schnecker J, Borken W, Schindlbacher A, Wanek W
2016 - Soil Biology and Biochemistry, 103: 300-307

Controls on the storage of organic carbon in permafrost soil in northern Siberia


This research examined soil organic carbon (SOC), total nitrogen (TN) and aboveground phytomass carbon (PhC) stocks in two areas of the Taymyr Peninsula, northern Siberia. We combined field sampling, chemical and 14C radiocarbon dating analyses with land cover classifications for landscape-level assessments. The estimated mean for the 0–100-cm depth SOC stocks was 14.8 and 20.8 kg C m−2 in Ary-Mas and Logata, respectively. The corresponding values for TN were 1.0 and 1.3 kg N m−2. On average, about 2% only (range 0–12%) of the total ecosystem C is stored in PhC. In both study areas about 34% of the SOC at 0–100 cm is stored in cryoturbated pockets, which have formed since at least the early Holocene. The larger carbon/nitrogen (C/N) ratio of this cryoturbated material indicates that it consists of relatively undecomposed soil organic matter (SOM). There are substantial differences in SOC stocks and SOM properties within and between the two study areas, which emphasizes the need to consider both geomorphology and soil texture in the assessment of landscape-level and regional SOC stocks.


  • This research addresses landscape-scale and regional variation in SOC stocks.
  • Landform and soil texture are taken into account in the analysis.
  • The contribution of phytomass to total ecosystem C stored is limited.
  • Large SOC stocks are susceptible to decomposition following permafrost thaw.

Palmtag J, Ramage J, Hugelius G, Gentsch N, Lashchinskiy N, Richter A, Kuhry P
2016 - European Journal of Soil Science, 67: 478-491

Lecture series

Arbuscular mycorrhizas and organic nitrogen in soil – and the other microbes involved

Jan Jasna
Institute of Microbiology, Academy of Sciences of the Czech Republic
16:00 h
Friedrich-Becke Seminar Room, UZA 2 (Geozentrum), Althanstr. 14, 1090 Wien

Microbes, nitrogen and plant responses to elevated CO2

César Terrer
Imperial College, London
11:00 h
Conference room “Ökologie” Althanstr. 14, 1090 Wien

Microbial ecology, phylogeny and biochemistry in the soil cabon cycle

Bruce Hungate, Prof.
Center for Ecosystem Science and Society, Northern Arizona University, USA
10:30 h
Lecture Hall 4, UZA 2 (Geozentrum), Althanstraße 14,1090 Vienna