Analysis of floodplain forest sensitivity to drought

Area of Science:

• Ecology
• Forest Science
• Climate Change Impacts

Background:

• Floodplain forests are vital carbon sinks and productive ecosystems.
• Extreme weather events increasingly threaten these valuable ecosystems.
• Understanding their resilience to drought is crucial for conservation.

Purpose of the Study:

• Assess the productivity of a Czech floodplain forest using carbon uptake and stem variation data.
• Identify conditions promoting high ecosystem production and the impact of drought.
• Determine the soil water content threshold for drought stress onset.

Main Methods:

• Eddy covariance method for carbon uptake measurement.
• Dendrometers for monitoring stem radius variations.
• Analysis of data from 2015-2018, including the 2018 drought event.

Main Results:

• Contrary to hypothesis, a warm spring in 2018 led to record gross primary production (GPP) and evapotranspiration (ET).
• Ring-porous tree species demonstrated the highest resistance to drought conditions.
• A relative soil water content threshold of approximately 0.45 indicated the onset of drought stress.

Conclusions:

• Floodplain forest productivity can be high even with drought, influenced by seasonal conditions like warm springs.
• Specific species traits, like those in ring-porous trees, enhance drought resilience.
• Identifying drought thresholds is key for predicting ecosystem responses to climate change.