The Impact of Different Grazing Periods in Dry Grasslands on the Expansive Grass <Emphasis Type="Italic">Arrhenatherum elatius</Emphasis> L. and on Woody Species

Dry grasslands are one of the most species rich and endangered types of vegetation in Europe. In the Czech Republic, dry grasslands are mainly of anthropogenic origin and were formed as a result of grazing after the clear-cutting of thermophilous oak woods. Gradual changes in the farming landscape throughout the 20th century, particularly in the 1960s, resulted in the abandonment of the relatively infertile habitats of dry grasslands. After abandonment, dry grasslands decline and degrade due to the gradual overgrowth of woody species and expansion of perennial tall grasses. In the year 2000, a grazing management program was introduced in the protected areas within the territory of Prague City to maintain the species diversity of dry grasslands. The responses of the expansive grass species, Arrhenatherum elatius L. and multiple woody species (especially, Prunus spinosa L.) to differences in grazing periods were monitored for over a decade. Grazing in spring through the end of June had the greatest impact on the reduction of A. elatius and woody species. Grazing in the height of summer through autumn did not reduce the cover of these plants, and may support the prosperity of both A. elatius and the woody species due to higher levels of nutrients.