Flakaliden Research Study:
Long-term field experiment to test the impact of climate change on forest growth
Project info
Status: Beginning equipment procurement
Span: 2025-2031
Location: Flakaliden Experimental Forest, Vindeln, Sweden
Contact:
Project direction: Hyungwoo Lim, Jose Gutierrez Lopez, Hjalmar Laudon, (Jose.Lopez@slu.se, Hyungwoo.Lim@slu.se, Hjalmar.Laudon@slu.se)
The beginning of a new flagship research project
This field experiment is funded by the Kempe Foundations with SEK 7 million. It is co-funded by the Knut and Alice Wallenberg Foundation with an equal amount, as part of a major investment in research infrastructures within the Wallenberg Initiatives in Forest Research (WIFORCE). In this project we will:
Manipulate earlier snowmelt, to see whether increased runoff in spring leads to water shortages in summer.
Manipulate summer drought, by excluding rainfall to the ground. Some plots are also fertilized, to study how fertilization affects tree drought tolerance.
Increase air temperature, using special climate chambers where researchers also monitor the trees’ water transport systems.
As the air becomes warmer and drier, trees lose more water to the atmosphere. In the worst case, this can damage the trees’ water transport system – a phenomenon known as cavitation – and lead to long-term growth declines, even if weather conditions later improve.
A world-class experimental design
The Flakaliden project has reached a major milestone: Procurement is officially complete. With all hardware secured, the project is now shifting gears from the acquisition phase to active programming, assembly, and field deployment.
This expansion transforms our monitoring capabilities, moving us toward a fully integrated, high-resolution view of the ecosystem's "pulse."
Phase 2: From Hardware to Insights
Now that the equipment is on-site, our technical focus turns to ensuring these diverse sensors speak the same language. The upcoming weeks will involve:
Programming: Configuring data loggers to sync multiple sampling rates and ensuring robust data transmission protocols.
Assembly: Integrating sensors into durable, weather-shielded housing units tailored for the Flakaiden environment.
Deployment: Strategic installation across the site to capture the full Soil-Plant-Atmosphere Continuum (SPAC).
Key Additions & Their Strategic Value
The new sensor suite allows us to bridge the gap between environmental "supply" and plant "demand."
1. Below-Ground & Hydrological Dynamics
Soil Temperature, Water Content and Potential: These allow us to move beyond simple moisture levels to understand exactly how hard a plant must "work" to extract water from the soil.
Groundwater Depth & Temperature: Essential for tracking the water table's influence on root zones and the thermal stability of the subsurface environment.
2. Atmospheric Drivers
Air Temperature & Relative Humidity: Combined, these define the Vapor Pressure Deficit (VPD), the primary atmospheric "tug" that pulls water through the trees. Our goal is to track VPD at various heights in the forest.
Photosynthetically Active Radiation (PAR): Directly measures the light energy driving photosynthesis, allowing us to correlate growth with available solar energy.
Snow Depth: Provides critical data on winter insulation for roots and the timing of the spring "recharge" for the water table.
3. Plant-Level Physiology (The Tree "Heartbeat")
Sap Flow & Point Dendrometers: These measure the actual movement of water through the xylem and the microscopic growth/shrinkage of the trunk, giving us real-time feedback on tree health.
Stem Water Content & Potential: These sensors provide a rare look into the tree's internal plumbing—revealing how much water is stored in the wood and how much "stress" the hydraulic system is under during dry spells.
Deployment Summary Table
Hydrology: Soil/GW Temp, GW Depth, Soil PotentialMaps water availability and thermal stress.
Atmosphere: Air Temp, RH, PAR, Snow DepthQuantifies the environmental "demand" on the system.
Physiology: Sap Flow, Dendrometers, Stem PotentialTracks the actual biological response to the environment.
Next Steps
Now that we are entering the build phase, things are going to get much more hands-on. I am sure I will be posting progress on my IG account. I promise I won’t post so many dog videos.
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