EcoDrive: Unravel the changing contributions of abiotic vs. biotic drivers of ecosystem gas exchange under weather extremes

Context

Extreme weather events (e.g. droughts, heat waves, very mild winters) and long-term climatic change will substantially affect carbon dioxide (CO₂) and water (H₂O) exchange of terrestrial ecosystems. Altered interactions and feedbacks at the land-atmosphere interface are the consequence. Process-based models provide coarse insights in ecosystem functioning based on our understanding of its abiotic and biotic drivers. This understanding relies on two complementary techniques: (1) the eddy covariance method which is the only available technique to actually measure CO₂ and H₂O exchange dynamics at high temporal resolution along with abiotic drivers in situ at ecosystem level; and (2) remote sensing, providing complementary temporal snapshot information on biotic drivers at larger spatial scales.

Our project will contribute to the external pageCOST Action SENSECOcall_made.

Project aims

We hypothesize that analysing extreme events with a multi-data approach will gain mechanistic understanding on spatio-temporal contributions of abiotic vs. biotic drivers for ecosystem gas exchange under changing weather and climate. The evaluation of this hypothesis is based on three questions:

1. How does the impact of abiotic vs. biotic drivers on ecosystem gas exchange change under extreme compared to current conditions?
2. Does an integrated multi-data approach allow scaling in situ gas exchange measurements and reliably representing ecosystem gas exchange under extreme conditions?
3. What are observational requirements and resulting uncertainties of such a multi-data approach?

We address these questions with multi-sensor data at three well-instrumented Swiss ecosystems (i.e. mixed forest (Lägeren), coniferous forest (Davos), arable system (Oensingen)).