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 page COST Action SENSECO.

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)).