Fine root production and nitrogen content in roots of Pinus sylvestris L. after clear-felling

Effects of clear-felling on fine root production and N content in roots were studied in a Scots pine (Pinus sylvestris L.) stand. A plot was clear-felled and root samples were compared with a control plot. Even if reduced by 50%, a significant fine root (diameter < 2 mm) growth was noticed up to 1 yr after the celar-felling. For live roots (diameters 2-4 and 4-6 mm) nitrogen content in root-wood and root-bark samples from the clear-felling, compared with the reference plot, were 30-50% already higher 2 months after the clear-felling. The difference did not increase in later comparisons. Nitrogen content in buttresses did not differ during the period studied, except for a higher percentage in bark at the clear-felling after two summers. A second study confirmed the results. It is suggested that there exists a continued nitrogen uptake in live roots after a clear-felling.