Monitoring of Vegetation Changes in Selected Sinkholes in the Moravian Karst, Czech Republic

Abstract

Sinkholes are very important phenomenon increasing the diversity in karst landscape. Twenty sinkholes in the area of Moravian karst have been monitored since 2000. Plant recording and phytosociological releves have been performed twice a year. The sinkholes are located at karst plateau, with intensive agriculture, resulting in very intensive erosion and underground water eutrophisation and pollution. That is why grassland belts were established along most sinkholes to decrease the level of erosion and eutrophisation. It was partly successful, but especially in the central part of the sinkholes ruderal plant species prevailed. The most predominant ruderal species are Urtica dioica, Agropyron repens and Cirsium arvense. After spraying total herbicide and sowing a special seed mixture in the year 2010 the situation significantly improved. Total number of plant species before the treatment varied from 19 to 86, while the actual numbers are from 30 to 78 per sinkhole. Basing on the results of the monitoring, managements were proposed and applied. The most important management practices are 2–3 cuts per year, removing the biomass, keeping the grassland belt around the sinkhole and planting groups of native small trees and shrubs in order to form natural formations for animals.