COMPARATIVE POLLINATION ECOLOGY OF TWO RARE DUTCH GENTIANA SPECIES, IN RELATION TO POPULATION SIZE

Gentiana pneumonanthe and G. cruciata need a pollination vector to secure their reproductive success, although no genetical barrier prevents selfing. Their pollination is mainly carried out by bumblebees (Bombus pascuorum). There is a dramatic reduction in reproductive output for both species when population size (number of flowering individuals) decreases too much.