The biogenic silica extracted from samples of 28 alpine plant species belonging to 23 genera and nine families collected in the Swiss Alps (Valais) accounted for between 0.01 and 5.9% of the dry biomass of leaves and wood. Silica content, and plant contribution to the soil biogenic silica pool, varied widely among taxa. Plant net productivity and biogenic silica production From this study and from the literature have been used to predict the input made by different subalpine and alpine plant communities to soil-borne phytolith assemblages, and their contribution to the silicon biocycle. (C) 2001 Annals of Botany Company.