Periodic Reporting for period 1 - PRIMETIME (Rhizosphere priming: Quantifying plant impacts on carbon dioxide emissions from a warming Arctic)
Berichtszeitraum: 2022-09-01 bis 2025-02-28
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?
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?
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.
- 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.
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.