Effects of reforestation and intensified land use on vascular plant species richness in traditionally managed hay meadows

In this study of 130 sites with different management we investigated whether vascular plant species richness is significantly reduced when traditionally managed hay meadows are abandoned and reforested. We also compared the effects of reforestation with those of intensified land-use to see which have the largest effects on species richness. Finally, we investigated the relative importance of relevant ecological factors for species richness. While the use of artificial fertilizers in traditionally managed hay meadows has resulted in significantly lower species richness, and intensive cultivation in even lower species richness, abandonment with reforestation has not decreased the species richness significantly. Productivity and habitat diversity have determined the species richness of meadows on the scale (0.03-5.1 ha) of this study. Low productivity is a prerequisite for high species richness in meadows. Maximum species richness was observed in unproductive, old, traditionally managed hay meadows with a high soil pH and high habitat diversity. The high species richness of these meadows suggests that they are in urgent need of conservation.