Biomass production and allocation, including fine-root turnover, and annual N uptake in lysimeter-grown basket willows

摘要

Annual net primary production (NPP) and N uptake were estimated for lysimeter-grown basket willows (Salix viminalis L.) during 3 years after planting. The willows were grown in a stand structure and continuously supplied with water and liquid fertilizer through drip tubes. The lysimeters contained either clay from the site or washed quartz sand. Shoot growth and leaf litter were measured and fine-root dynamics observed in minirhizotrons. Destructive samples were taken annually in late autumn and entire root systems were washed out. Dry mass and N content of all plant parts were determined. Fine-root production was estimated by two methods, based on destructive samplings and observations in minirhizotrons.