Forest Cover Loss in Upper Valais 2020-2024
Satellite-derived analysis showing 340 hectares of protective forest loss in Upper Valais due to bark beetle outbreaks exacerbated by drought, with implications for avalanche and rockfall protection.
Provenance
Legal Citation
WSL. (2025). Protective Forest Decline in Upper Valais: Satellite Analysis 2020-2024 (Research Paper 2025-11). Retrieved from https://opengovclimate.ch/en/evidence/forest-cover-loss-valais/
Location
Measurement Period
A WSL satellite analysis reveals that 340 hectares of designated protective forest in Upper Valais were lost between 2020 and 2024, representing a 4.2% decline. The primary driver was European spruce bark beetle (Ips typographus) outbreaks, whose severity was exacerbated by consecutive drought years.
Key Findings
- Total protective forest loss: 340 hectares (4.2% of designated area)
- Primary cause: Bark beetle (Ips typographus) — 78% of loss area
- Secondary causes: Drought stress (15%), windthrow (7%)
- Most affected elevation band: 1,200-1,600m
- Affected municipalities: Visp, Stalden, Saas-Grund, Zermatt
Legal Significance
Under WaG Art. 20, cantons must ensure the preservation of protective forests. WaG Art. 35 requires replacement when protective forest is lost. The 4.2% decline may constitute a failure to maintain protective forest functions for avalanche and rockfall mitigation, creating grounds for liability claims from affected communities.