Central scientific challenge of my research
I aim to uncover how processes of terrestrial carbon (C) cycling are controlled by interactions between soil microorganisms and plant communities along natural and human-induced gradients of environmental stresses. Better understanding of the terrestrial carbon cycling processes, is of ultimate importance for humanity, because soil-atmosphere carbon dynamics directly affects Earth climate. Regulation of soil-atmospheric carbon circulation, and enhancement of accumulation of carbon in soil are among the most promising pathways to fulfill the United Nations sustainable development goal of climate change mitigation. Both applied and fundamental aspects of this research are prominent topics within ecological and environmental sciences, because of their theoretical importance for understanding fundamentals of ecosystem functioning, and because of the direct relevance of the obtained findings for modern society, as highlighted by the European Green Deal agenda and Post-2020 Global Biodiversity Framework adapted by the United Nations.
Our current understanding of the mechanisms controlling the balance between amount of C in the atmosphere and soil is poor. This balance is known to be an interplay of two major processes, both strongly affected by plant-microbial interactions. The first process comprises assimilation of atmospheric carbon by plants though the photosynthesis process, followed by plant death that allows carbon stored in the plant biomass to be released into soil as plant litter. Soil microorganisms, especially those living in symbiotic relation with plants, control plant community composition, productivity, and plant litter chemical composition, therewith indirectly affecting transfer of carbon from atmosphere to plants and further to the soil. The second process comprises transformation of the plant-assimilated carbon into soil organic matter, directly enabled by soil microorganisms that receive carbon from living plants in exchange for nutrients within symbiotic associations, and decompose plant litter, aiding accumulation of soil organic matter and release of carbon into the atmosphere.
Despite the recognized importance of soil microorganisms in both direct and indirect pathways of atmosphere-plant-soil carbon transfer, the complex interplay of the eco-physiological mechanisms enabling these pathways is understood very poorly, especially so in quantitative terms. This lack of mechanistic and quantitative understanding of belowground processes is recognized as a principal source of uncertainty in our quantifications of global terrestrial biogeochemical cycles. Acquiring this knowledge is of critical importance for humankind, as it enables the development of conscious land management strategies aimed to store more carbon in soil and to mitigate climate change.
Research program
I aim to enable the paradigm shift from vegetation-centered understanding of soil-atmosphere carbon balance to a comprehensive and quantitative view of the interplay of plants and soil microorganisms being the ultimate driver of terrestrial carbon balance. In order to enable this shift I combine thorough experimental-based research on interactions between functioning of soil biota, plant communities, and terrestrial carbon cycling, and development of quantitative mathematical models of large scale and long-term impacts of these interactions on functioning of ecosystems and on terrestrial carbon cycling.
My research comprises three themes:
Experimental-based understanding of the mechanisms of microbial impacts on the carbon dynamics along the atmosphere-vegetation-soil pathway.
Hereto my research group conducts field and laboratory-based experimental research on the microbially-enabled mechanisms of soil C sequestration, and on the relation between microbial abundance, community composition, and plant community composition and functioning.
Global patterns in above-belowground interactions, and environmental drivers of these patterns.
In order to be able to upscale the knowledge about plant-soil interactions and their impacts on biogeochemical cycles and provisioning of ecosystem services, my research group conducts quantitative assessments of spatial distribution of soil biota in terms of both species richness and functional diversity.
Quantifications and modelling of the role of plant-microorganism interactions in terrestrial carbon cycling.
As many aspects of soil-atmosphere carbon cycling operate at time scales longer than decennia, many questions related to links between ecosystem functioning and soil-atmosphere carbon balance can be answered only through computer modelling. Efficient parametrization of these models, and understanding and evaluating their results requires development and use of quantitative ecological methods, and among those – the novel methods for quantitative assessments of microbial impacts on soil processes. Both, novel model development, and quantitative assessments of plant and soil biodiversity impacts on carbon cycles, constitute an important part of my research program.
The outcomes of the three research lines provide important theoretical and practical insights, aiding scientific understanding of environmental drivers of terrestrial carbon cycling, as well as development of policy and land-management tools for controlling the carbon balance and climate on Earth.