CHANGES IN THE MOSS FLORA OF THE NETHERLANDS

From 1900 onwards, changes in abundance of Dutch moss species have been recorded. Some species have declined (23%, of which 4% have become extinct), while others have increased (28%, of which 9% were species unrecorded earlier). The declining species show a preference for oligotrophic habitats, mainly marshes, which have become threatened during recent decades. The increasing species mostly occur on bare soil, riverbanks and walls. They are rather tolerant to disturbance and are predominantly more or less associated with eutrophic habitats. Apart from extinction and changes in species abundance, species-fitness also appears to be affected, such as a decline in sexual reproduction and in the size of the gametophyte. Such changes can be observed in various species, and may lead to a decline in the near future-although some of these species are still fairly abundant.