Eglinton Timothy

The molecular footprint of conifers - A new approach to unveil past vegetation

Project Number: CH-4936
Project Type: Research_Project
Project Duration: 08/01/2013 - 07/31/2015
Funding Source: other ,
Project Leader: Prof. Timothy Eglinton
Geologisches Institut
ETH Zürich
ETH Zentrum NO
Sonneggstrasse 5, ETH Zentrum NO G 59
8092 Zürich
Phone: ; +41 (0) 44 632 36 65
FAX:
e-Mail: timothy.eglinton(at)erdw.ethz.ch
http://www.erdw.ethz.ch

related to this project.
for which the project has a relevance.


Research Areas:
Landscape

Disciplines:
environmental sciences

Keywords:
  • Earth Sciences

  • Soil Sciences

  • Biogeosciences

  • Mountain forest ecosystems

  • Plant biomarkers

  • Molecular composition of plant materials, litter and soil

  • incorporation and turnover of plant biomarkers in soil

  • organic matter degradation

  • compound-specific radiocarbon analysis


    Abstract:
    Molecular markers (biomarker) are widely applied to fingerprint the origin of fossil organic material. Especially compounds derived from the resin of conifers are highly specific for individual taxa up to species level. However, this approach rarely has been applied to fossil organic matter preserved in (fossil) soils and terrestrial sediments sensu stricto, mainly due to the limited knowledge on a) the fate of these compounds including changes of the characteristic molecular fingerprint from plant to soil and with time, and on b) ecosystem specific biomarker fingerprints of soils. Alpine conifer forest ecosystems such as those preserved in the Swiss Nationalpark represent potential modern analogues for last glacial forest environments in Central and SE-Europe, however, the biomarker fingerprint of these ecosystems is unknown. The goals of this project are to understand incorporation pathways of conifer biomarkers in soils and changes of the biomarker fingerprint involved with this process. Moreover, for the first time characteristic biomarker fingerprints for potential glacial analogs forest ecosystems will be derived. These goals will be achieved by analysing the biomarker inventory of plant tissues, litter and topsoils from alpine conifer forests (e. g. Pinus mugo and Larix forest ecosystems in the Swiss National Park). Additionally, a method for 14C dating of the individual conifer biomarker will be established. Using 14C dating of conifer biomarkers in topsoils, mean residence times of these compounds in soils will be assessed. The sampling of the forest ecosystems has been conducted in 2013 and fingerprint analysis as well as method development for compound-specific radiocarbon analysis are currently performed. The field program for 2014 focus on grasland sites within the mountain forest altitudinal belt. Using sites with known dates of forest to grassland conversion, ranging from the medieval to the modern times, it will be investigated if biomarkers of conifer origin still can be identified in the grassland topsoils, decades and centuries after the land use change. The goal is to test if a combination of resin-derived biomarkers and compound-specific 14C dating provides an innovative tool to reconstruct land use changes in the alpine realm, using topsoils as environmental archives. The outcome of this project will furthermore significantly help to improve the interpretation of fossil biomarker fingerprints from paleosols and sediments for reconstructing past forest vegetation such as the forest history during the last glacial or the historical deforestation of the Alps.

    Leading questions:
    What is the molecular footprint of various mountain conifer ecosystems in soils and sediments?
    What characteristics in the molecular composition of the soil organic matter allows an identification and distinction of various forest ecosystems?
    Is the molecular footprint of the conifer ecosystems distinctive and stable enough to allow identifying past vegetation changes from (modern) soils
    What is the source of various plant biomarkers and how are they incorporated in soils?
    What is the turnover and degradation rates of the molecular markers in the soils?


    Last update: 12/29/16
    Source of data: ProClim- Research InfoSystem (1993-2020)
    Update the data of project: CH-4936

    Go Back