Salix myrtilloides in north central Poland. Distribution, threats and conservation

Present status of a postglacial relict – Salix myrtilloides L. was investigated in north central Poland at 27 localities. Consequently 3 sites were confirmed, 4 were not confirmed, and the remaining 20 were considered to be extinct. In comparison to the historical distribution, ca. 74% of the sites existing 50 years ago do not exist today in the studied region. The confirmed populations were found near Oporówek (ca. 1600 stems), Rakowiec (ca. 100) and Bobrowo (15). At three sites confirmed in this study, the existence of vigorous hybrids between S. myrtilloides and S. aurita L. (S. ×onusta Besser) were observed. The most important threats to Salix myrtilloides L. populations in the studied region were assessed to be hybridization with other commonly occurring willow species, site isolation and habitat destruction. Natural habitat protection with adequate buffer zone and gene pool protection in a form of plantations was suggested as a conservation strategy. As an alternative strategy active protection ‘insitu’ was proposed based on cutting competitive common species of willows.