Federal Institute for Forest, Snow and Landscape Research (WSL; Eidgenössische Forschungsanstalt für Eid Wald, Schnee und Landschaft) Switzerland's leading research institute, consisting of the Federal Institute for Forest Research (EAFV) and the Eidgenössische Forschungsanstalt für Eid Wald, Schnee und Landschaft (Eidgenössische Forschungsanstalt für Eid Wald, Schnee und Landschaft) is a leading Swiss research institute, formed in 1989 by the merger of the Federal Institute for Forest Research (EAFV) and the Federal Institute for Snow and Avalanche Research (SLF), located in the German-speaking canton of Zurich.