Abstract
Distribution of the two taxonomic groups in Vaccinium oxycoccus sensu lato, V. oxycoccus sensu stricto and V. microcarpum, overlaps geographically, forming a sympatric field. Habitat segregation of the two types along micro-scale environmental gradients was studied in Bekanbeushi peatland, northern Japan. V. oxycoccus s.s., which has pubescent pedicels and larger leaves, occupies wetter zones with shallower groundwater tables, higher groundwater pH, and higher groundwater conductivity along the environmental gradients. V. microcarpum, which has glabrous pedicels and smaller leaves, occupies drier zones with deeper groundwater tables, lower pH, and lower conductivity. Distribution ranges of V. oxycoccus s.s. along groundwater chemistry gradients are much broader than V. microcarpum. Distribution of the two types is neighboringly sympatric rather than biotically sympatric in terms of micro-scale environmental gradients.
