The biomass production and stand structure of Salix 'Aquatica' planted on abandoned farmland and harvested after 3 and 7 year rotations was studied in southern Finland for 10 years. Coppicing doubled the stand density to 3.5 x 10(5) shoots ha(-1). Self-thinning began during the first growing season and shoot mortality amounted to 13%-20% at the end of the first growing season. Cumulative shoot mortality of the initial sprout number at the end of the first rotation (3 years) was 60%; the corresponding figure at the end of the second rotation (7 years) was 87%. The diameter distribution at the beginning of self-thinning resembled a bidomal distribution. The second self-thinning phase began at the age of four years. The mean annual leafless above-ground biomass production was higher during the second (7.7 t ha(-1)) than during the first rotation (5.1 t ha(-1)). The annual increment varied highly depending on the temperature sum and losses caused by pathogens. The leaf area index of 1-3 year old sprouts varied between 4.9 and 6.4 m(2) m(-2).