WSL Drought Initiative 2018

The 2018 summer half-year brought Switzerland (but especially Central and Northern Europe) one of the most pronounced droughts of recent decades. This has resulted in record-low runoff, extreme soil dehydration, severely limited water uptake by vegetation and exceptionally early leaf discoloration. The WSL with its core business in the field of forest, hydrology and biodiversity was particularly in the focus of this drought situation and is now required to investigate the events and impacts of this summer and to derive new insights into how to deal with similar situations in the future.

The aim of this extraordinary WSL initiative is to quickly answer specific questions arising from the extreme drought of summer 2018. In particular, the aim is to ensure that the WSL is equipped at the beginning of summer 2019 to assess and predict the situation even better in the event of a renewed drought.

Schweizerische Zeitschrift für Forstwesen, Volume 171, Issue 5, September 2020 (With English and French abstracts, articles chargeable):

Perspektiven · Perspectives

Erkenntnisse aus der Trockenheit 2018 für die zukünftige Waldentwicklung (Andreas Rigling; Manfred Stähli)

Wissen · Connaissances

Waldschäden wegen Dürre von 1864 bis 2018 in der Schweiz und insbesondere im Kanton Zürich (Ursina Rathgeb; Matthias Bürgi; Thomas Wohlgemuth)

Früher Laubfall der Buche während der Sommertrockenheit 2018: Resistenz oder Schwächesymptom? (Thomas Wohlgemuth; Martin Kistler; Celine Aymon; Frank Hagedorn; Arthur Gessler; Martin M. Gossner; Valentin Queloz; Irina Vögtli; Ulrich Wasem; Yann Vitasse; Andreas Rigling)

Auswirkungen des Trockensommers 2018 auf Flächen der Interkantonalen Walddauerbeobachtung (Sabine Braun; Lucienne C. de Witte; Sven E. Hopf)

Blitzschlagbrände und Sommertrockenheit: Gibt es einen Zusammenhang? (Jose Vazquez Moris; Marco Conedera; Luca Nisi; Gianni Boris Pezzatti)

Akzeptanz von Massnahmen bei Trockenheit: Bevölkerungsbefragung zum Extremsommer 2018 (Marius Fankhauser; Matthias Buchecker)

NOTIZEN · BlOC-NOTES

Notizen · Bloc-Notes

Themes

Drought classification

• A1-Historical contextualization of tree damage caused by the 2018 drought

• A2-How extreme? Overall assessment of the 2018 drought

Early detection of drought

• B1-The 2018 drought - how predictable was it?
• B2-Assessing forest vulnerability to drought by intersecting modeled soil water availability (SWA) with remote-sensing derived spectral anomalies

Early leaf discoloration (leaf fall)

• C1-Identification of drought risk zones in current beech stands
• C2-Effects of the drought of summer 2018 and heat on forest canopy greenness
• C3-Analysis of beech litterfall in the drought year 2018
• C4-Droughtindicators: TreeNet meets Sentinel 2

Lightning-induced fires

• D1-The influence of a summer drought on lightning-induced fires

Medium- and long-term effects

• E1-Rapid survey of the short-term effects of the 2018 drought on beech forests in Switzerland
• E2-Response of European beech and silver fir trees on dry sites to the drought in 2018
• E3Medium-term effects of the drought of summer 2018 on beech individuals with early leaf senescence

Public perception

• F1-Media perception of the 2018 drought