Postdoctoral Research Associate for the Project ”Impacts of mosses and lichens on permafrost soil carbon dynamics since the last glacial (MoLiCarb)”
Universität Hamburg
Climate: Past, Present & Future (CL)
Stratigraphy, Sedimentology and Palaeontology (SSP)
The MoLiCarb project aims to assess the role of vegetation, in particular mosses and lichens, for carbon content of permafrost soils at high latitudes and associated climate impacts. Effects of mosses and lichens on the soil carbon balance and their consequences for climate are currently poorly represented in Earth System Models (ESMs), although they maybe highly relevant, particularly at high latitudes (carbon input, soil cooling). Permafrost soil carbon in these regions is of great importance for future climate, since thawing of the soil will likely lead to strong emissions of CO2 and a positive feedback on global warming. More advanced models of moss and lichen effects on high-latitude ecosystem carbon fluxes that can inform ESMs are therefore urgently needed. While observational data for current climatic conditions are usually not sufficient to constrain model projections on coupled vegetation-soil carbon dynamics at high-latitudes for the next decades, sedimentary ancient DNA (sedaDNA) may help to quantify the long-term relationships between vegetation, climate, and soil carbon and thus reduce this uncertainty substantially.
In MoLiCarb, we will address the following questions: 1) How strong is the effect of mosses and lichens on today’s dynamics of soil carbon in permafrost regions? 2) To what extent did mosses and lichens contribute to build-up of soil carbon since the last glacial maximum? 3) How will mosses and lichens affect permafrost carbon release in the next decades?
The postdoc will further develop and apply a process-based numerical model that is able to predict physiological properties and functional diversity of moss and lichen communities and their effects on the C balance of ecosystems on the basis of climate and other environmental data. The model will be extended by the most relevant soil processes of permafrost regions and updated vascular vegetation, and validated using sedaDNA data collected in a cooperating project, complemented by other data sources. With the new model version, it will be possible to reconstruct the dynamics of permafrost soil carbon at high latitudes since the last glacial maximum. Subsequently, the model will be used to predict carbon emissions from soil for the next decades, taking into account the effects of mosses and lichens. This we will make a substantial contribution to the improvement of future Earth system models, which estimate the role of permafrost soil carbon for global warming.
The work will be conducted in close collaboration with the partner institution Alfred Wegener Institute at the Helmholtz Center for Polar and Marine Research in Potsdam, Germany.