• 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

  • First Soil Ecology Workshop at DMES

    14.06.16
    Event

    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

    19.05.16
    News

    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

    26.04.16
    People

    Congratulations!

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

  • Field course in Costa Rica February 2016

    07.03.16
    News

    Wolfgang Wanek, Andreas Richter and Christina Kaiser just returned from a field course in Costa Rica, where they studied soils, plants and ants together with Veronika ...

Latest publications

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

Summary


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.


Highlights

  • 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

Drought history affects grassland plant and microbial carbon turnover during and after a subsequent drought event

Summary

  1. Drought periods are projected to become more severe and more frequent in many European regions. While effects of single strong droughts on plant and microbial carbon (C) dynamics have been studied in some detail, impacts of recurrent drought events are still little understood.
  2. We tested whether the legacy of extreme experimental drought affects responses of plant and microbial C and nitrogen (N) turnover to further drought and rewetting. In a mountain grassland, we conducted a 13C pulse-chase experiment during a naturally occurring drought and rewetting event in plots previously exposed to experimental droughts and in ambient controls (AC). After labelling, we traced 13C below-ground allocation and incorporation into soil microbes using phospholipid fatty acid biomarkers.
  3. Drought history (DH) had no effects on the standing shoot and fine root plant biomass. However, plants with experimental DH displayed decreased shoot N concentrations and increased fine root N concentrations relative to those in AC. During the natural drought, plants with DH assimilated and allocated less 13C below-ground; moreover, fine root respiration was reduced and not fuelled by fresh C compared to plants in AC.
  4. Regardless of DH, microbial biomass remained stable during natural drought and rewetting. Although microbial communities initially differed in their composition between soils with and without DH, they responded to the natural drought and rewetting in a similar way: gram-positive bacteria increased, while fungal and gram-negative bacteria remained stable. In soils with DH, a strongly reduced uptake of recent plant-derived 13C in microbial biomarkers was observed during the natural drought, pointing to a smaller fraction of active microbes or to a microbial community that is less dependent on plant C.
  5. Synthesis. Drought history can induce changes in above- vs. below-ground plant N concentrations and affect the response of plant C turnover to further droughts and rewetting by decreasing plant C uptake and below-ground allocation. DH does not affect the responses of the microbial community to further droughts and rewetting, but alters microbial functioning, particularly the turnover of recent plant-derived carbon, during and after further drought periods.
Fuchslueger L, Bahn M, Hasibeder R, Kienzl S, Fritz K, Schmitt M, Watzka M, Richter A
2016 - Journal of Ecology, 104: 1453-1465

Carbon isotope composition of carbohydrates and polyols in leaf and phloem sap of Phaseolus vulgaris L. influences predictions of plant water use efficiency

The use of carbon isotope abundance (δ13C) to assess plant carbon acquisition and water use has significant potential for use in crop management and plant improvement programs. Utilising Phaseolus vulgaris L. as a model system, this study demonstrates the occurrence and sensitivity of carbon isotope fractionation during the onset of abiotic stresses between leaf and phloem carbon pools. In addition to gas exchange data; compound-specific measures of carbon isotope abundance and concentrations of soluble components of phloem sap were compared to major carbohydrate and sugar alcohol pools in leaf tissue. Differences in both δ13C and concentration of metabolites were found in leaf and phloem tissues, the magnitude of which responded to changing environmental conditions. These changes have inplications for the modelling of leaf level gas exchange based upon δ13C natural abundance. While estimates of δ13C of low molecular weight carbohydrates and polyols increased the precision of predictions of water use efficiency compared to those based on bulk soluble carbon. The use of this technique requires consideration of the dynamics of the δ13C pool under investigation. Understanding the dynamics of changes in δ13C during movement and incorporation into heterotrophic tissues is vital for the continued development of tools that provide information on plant physiological performance relating to water use.

Smith M, Wild B, Richter A, Simonin K, Merchant A
2016 - Plant and Cell Physiology, 57: 1756-1766

Lecture series

Microbes, nitrogen and plant responses to elevated CO2

César Terrer
Imperial College, London
19.07.2016
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
22.01.2016
10:30 h
Lecture Hall 4, UZA 2 (Geozentrum), Althanstraße 14,1090 Vienna