The influence of agricultural land-use intensity on bryophyte species richness

This study is a quantitative approach to the estimation of bryophyte specie s richness in relation to land-use intensity at three spatial scales in hig hly cultivated areas. A total of 460 randomly selected habitats and their v arious substrates within 29 study sites were investigated with regard to th eir land-use intensity and their bryophyte species richness in an agricultu ral region of eastern Austria. On bare soils (substrate-scale), low but reg ular disturbance increases bryophyte diversity in comparison to lower land- use intensity. However, more frequent disturbance (e.g. ploughing more than two times a year) dramatically reduces species richness at these sites, wi th more than 50% of these sites showing no bryophytes. The production of re productive units (sporophytes and vegetative units) is highest at an interm ediate disturbance regime. On the habitat, as well as on the landscape-scal e, there is a significant increase in total bryophyte species number as wel l as in the number of threatened species with decreasing land-use intensity . This is mainly due to habitat and structural diversity, which increases w ith decreasing land-use intensity. There are significant correlations betwe en landuse intensity, structural diversity and species richness at the habi tat as well as on the landscape scale.