Last changed: 02 June 2023
Forest. Photo.

The Integrated Monitoring area Gammtratten is situated 100 km  west of Umeå and roughly 50 kilometres southeast of Åsele near the little village of Norrtjärn. The site is part of a 754 ha nature reserve. Forest fires more than 100 years ago on dry slopes.



  • International code: SE16 
  • Latitude/longitude: N63°51´ E18°07´ 
  • National Grid: 708571/161410 
  • County : Västernorrlands (Y) 
  • Municipality: Örnsköldsvik 
  • Land owner: State
  • Size of catchment: c:a 45 ha 
  • Long-term average precipitation (not corrected): about 750 mm 
  • Long-term average temperature: about +1,2 °C 
  • Snow cover: about 175 days
  • Length of vegetation period (mean temp. > +5°C)/: about 145 days
  • Biome: middle boreal
  • Dominant vegetation type: Norway spruce - Vaccinium myrtillus forest
  • Dominant soil type: Podzol
  • Bedrock: young granite and pegmatite
  • Air pollutant deposition: very small, deposition of N c:a 4 and S c:a 8 kg/ha/year 
  • Land-use history: Biggest trees felled around 1900. Light grazing by cattle up to the 1950´s.