The service is based on the berry crop observations made within the national network of observation forests according to the instructions provided on the website.
Five permanent observation areas are established in each forest. During the growing season, the number of flowers, unripe berries, and ripe berries is counted for each berry plant (bilberry, lingonberry, and cloudberry). Anyone can establish their own observation areas and register as an observer through the website. Observations are recorded on the site.
Natural Resources Institute Finland (Luke) and its predecessor Finnish Forest Research Institute have been collecting berry and mushroom crop observations since the 1990s. The observations are part of a forest plant phenology project, which monitored the rhythm of various biological phenomena and the impact of various factors on it: http://www.metla.fi/metinfo/fenologia/. The results have been made available to everyone and can be utilized by interested parties.
After the completion of the phenology project, Luke began cooperating with the Finnish 4H Federation to continue the collection of berry crop observations, which resulted in the creation of the open access website marjahavainnot.fi. Luke processes the observation data to produce maps and berry crop forecasts covering the entire country.
The website can be explored at marjahavainnot.fi