This investigation is based on analyses in 1992 and 1993 of the above- and below-ground biomass on permanent plots in a herb- and grass-rich birch woodland community (Lactucion alpinae alliance). The biomass (both above- and below-ground) decreases with increasing frequency in scything of the plots in a series: not scythed since 1950, scythed biennially, scythed annually. The number of individuals increases through this series. The plant cover also changes, as regards dominant species, from tall herbs (Crepis paludosa, Geranium sylvaticum, Geum rivale) to grasses (Agrostis capillaris). The differences in the moss layer are very distinct, from the scattered occurrence of bryophytes to a dense cover of Rhytidiadelphus squarrosus/subpinnatus in the intensively-scythed plots. Through the series referred to, the above-ground biomass changes from more than 2000 kg/ha to about 1000 kg/ha. The below-ground biomass changes from 4-5000 kg/ha to about 2000 kg/ha. There are considerable differences in both the number of shoots and the biomass between the compared years, perhaps partly due to a methodological bias and partly because of fluctuations in climatic conditions.