FORM DIVERSITY OF <i>PINUS SYLVESTRIS (PINACEAE) </i>IN NORTHERN DVINA BASIN
The study of <i>Pinus sylvestris</i> L. form diversity in pine plantations in the northern taiga subzone of the Northern Dvina basin. The frequency of forms with red anthers, yellow anthers, narrow crown, wide crown, «paludous», short needles, long needles and with tree needles in bundle was estimated in 107 plots. The diagnostic characters of defined forms were given. The large portion of red anther form was found in sparse pine forests of sphagnum group and in raised bogs. Form with a narrow crown dominated in all studied forests. The morphometric parameters of crown, stem and assimilation apparatus of different trees form were established in the case of sphagnum pine forests. It was found that the most promising in economic terms are forms with long needles, yellow anthers, narrow crown and pine with three needles in the beam.