Vegetation changes after cessation of grazing management in the Jizerske Mountains (Czech Republic)

Vegetation changes following the cessation of grazing of highly productive pasture in the Jizerske Mountains in 1997 were studied. The experiment included three replicate pairs of plots and data were collected before and after grazing was ended. Cover was estimated in 1-m(2) permanent plots. Abandonment of the pasture resulted in a significant decrease in plant species diversity. Annuals and perennials such as Trifolium repens and Poa trivialis disappeared within three years of the end of grazing. Species scores on the first ordination axis of RDA analyses, where time was the only explanatory variable were highly positively correlated with species heights obtained from the local flora and species height was the single parameter that best explained the reaction of species to the cessation of grazing. Within five years of abandonment, differences among swards caused by continuous stocking and rotational grazing had disappeared and tall grasses and shade-tolerant forbs dominated all swards. No new species were recorded after the abandonment of the pasture. If the abandoned grasslands will not reforest, alternative management regimes must be practiced in order to prevent their degradation and spread of tall dominants.