NEEDLE SIZE AND NITROGEN CONCENTRATION OF PINUS-SYLVESTRIS AND PINUS-CONTORTA

Needle mass, length, and nitrogen concentration, and their relation to site index were studied for lodgepole pine (Pinus contorta Dougl.) an d Scots pine (Pinus sylvestris L.). Needles were collected at 53 locat ions throughout Sweden where the two species, of the same age, were gr owing on adjacent, comparable sites. Sampling was done throughout the growing season, with a pause during the period of most active growth. Needles of lodgepole pine had a higher mass, were longer, and had a lo wer nitrogen concentration than those of Scots pine. Site index was po sitively correlated to needle length and weight for both species, and to nitrogen concentration for lodgepole pine. For the characteristics studied, the relative differences between needles of the two species d ecreased with increasing site index.