Swiss Federal Institute for Forest, Snow and Landscape Research WSL

TreeNet

The biological drought and growth indicator network

Point dendrometers continuously measure the stem radius of a tree. Trunks shrink during the day and expand again during the night. These diurnal stem radius fluctutaions are a consequence of the current water saturation of the tree.

TreeNet is an international monitoring and research network in which automated tree stem radius fluctuations measured with point dendrometers are analyzed in terms of forest ecosystem responses to climate change. A continuous stream of microclimate and tree physiology data provides real-time information on tree water relations and tree growth. 

Imbalances in tree water relations - quantified as tree water deficits - are interpreted as biological drought indicator for entire forest ecosystems.

Current stem growth rates are related to the ones of past years and interpreted as indicator for forest growth. Combinations of indicators are used as early predictors for the expected annual carbon sink of forest ecosystems.

TreeNet produces a set of data and elaborates methods which allows for resolving variables of tree water relations and stem growth in an hourly resolution. Such a high temporal resolution in combination with the large geographical area covered, particularly for tree growth, may be unique worldwide.

TreeNet closely collaborates with research groups at the eddy flux supersites Seehornwald Davos (LWF/ETHZ/SwissFluxNet/ICOS) and Lägeren (LWF/ETHZ/SwissFluxNet), the Long-term Forest Ecosystem Research Programme (LWF/WSL), the ETHZ, and the Institute for Applied Plant Biology (IAP).

TreeNet Switzerland Sites

TreeNet-Flächen 2016
TreeNet sites (2016)

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