Fine roots in a dry Calluna heathland

The fine roots in a dry Calluna vulgaris heathland are concentrated in the top soil. Over a 21-month period their dry mass varied from 303 to 612 g m~2, or from 15-7 to 55-2% of the total root mass in the top 5 cm of soil. In early summer and in late autumn to early winter there appeared to be peaks in fine root mass. Data suggest that fine root mass is correlated with moisture availability in the top soil. Nitrogen concentration of the fine roots averaged 17-3 mg g“1 and showed seasonal variation; Phosphorus concentration averaged 0-56 mg g"1 and did not show such variation.