Rhizosphere priming: Quantifying plant impacts on carbon dioxide emissions from a warming Arctic

Project Information

PRIMETIME

Grant agreement ID: 101039588

DOI

10.3030/101039588

EC signature date 7 June 2022

Start date 1 September 2022

End date 31 August 2027

Funded under

• European Research Council (ERC)

Total cost

€ 1 499 230,00

EU contribution

€ 1 499 230,00

Coordinated by

STOCKHOLMS UNIVERSITET
Sweden

Periodic Reporting for period 1 - PRIMETIME (Rhizosphere priming: Quantifying plant impacts on carbon dioxide emissions from a warming Arctic)

Reporting period: 2022-09-01 to 2025-02-28

Summary of the context and overall objectives of the project

The Arctic is warming four-times faster than the global average. This causes increased CO2 emissions from thawing permafrost soils that add to anthropogenic emissions, but also increased plant CO2 uptake under conditions more favorable for plant growth. The balance between these processes determines the future Arctic CO2 budget. In addition, plants can stimulate CO2 emissions from soils near their roots, via the rhizosphere priming effect. The intensity of priming is likely influenced by increasing plant productivity, deeper plant rooting favored by permafrost thaw, as well as changes in vegetation distribution such as northward-movement of the tree line, which can all already be observed across the Arctic.
PRIMETIME aims to provide the first observation-based estimate of total plant effects on circum-Arctic soil and ecosystem carbon stocks in a changing climate. Central questions include:
(1) How do different vegetation types affect soil and ecosystem carbon stocks and CO2 balance?
(2) How do changes in rooting depth interact with depth gradients of soil properties to affect carbon stocks and CO2 fluxes?
(3) What is the net effect of expected changes in plant productivity, vegetation distribution and rooting on ecosystem carbon storage across the circum-Arctic?

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Activities so far included
- a field campaign to the Canadian Arctic. Samples have been taken and transported to Stockholm;
- a field experiment on plant-soil carbon transfer. Samples have been taken and transported to Stockholm. Sample and data analyses are ongoing and manuscripts are in preparation.
- a laboratory experiment on how plants influence the surrounding soil. Sample and data analyses are ongoing and manuscripts are in preparation.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The first part of the project focused on experimental work, and sample and data analyses are ongoing. We are now shifting our focus towards data interpretation, manuscript writing, and dissemination of experimental results, as well as model integration.