Changes in the structure and floristic composition of the limestone grasslands after cutting trees and shrubs and mowing

Abstract

The calcareous grasslands belong to the species-rich plant communities in Poland. Most of them are of anthropogenic origin and they need specific management (i.e. periodical cutting suckers of trees and shrubs, grazing or mowing) in order to protect their floristic diversity. Many of calcareous grasslands have been overgrown by shrubs as a result of cessation of traditional management. The aim of this study was to compare the structure and dynamics of xerothermic hazel shrub patches, which were undergoing secondary succession with patches where different management practices aiming at restoration of species-rich limestone grassland were applied. The managed plots had a significantly higher species richness than the control one. However, they strongly differed in their floristic composition from well-preserved limestone grasslands. There were also significant differences observed between both the managed plots. Too intensive management, particularly frequent mowing of herbs resulted in expansion of grass species such as Brachypodium pinnatum and Calamagrostis arundinacea and caused a sharp decline in species richness.The species composition and turnover rate strongly depended on succesional stage (soil layer thickness) of plots at the start of the experiment. The deeper was the soil, the higher was the rate of species turnover and the smaller was the share of xerothermic and thermophilous species. The last mentioned group was dominated by species with a persistent seed bank in the soil, frequently colonizing anthropogenic habitats.

Plant Diversity-Environment Relationships in Xeric Grasslands of North-Eastern Romania

“…It had a pronounced negative effect in grazed compared to mown and a low positive effect in grazed compared to unused areas (Table 4). However, there was an increase in species richness in either mown or grazed terrains compared to the unused ones, which is consistent with results from other European dry grasslands where diversity was higher in managed areas (Bąba, 2003;Turtureanu et al, 2014). These results suggest that, in almost all xeric grasslands from North-Eastern Romania, species richness is highest in the low intensity mowed and grazed areas, which is consistent with the intermediate disturbance hypothesis (Grime, 1973).…”

Actual State and Changes of Flora and Vegetation in the Broczówka Steppe Reserve

“…In the area of Broczówka reserve, numerous species that were noted here 27 years KAPUŚCIŃSKI 1990;MICHALIK 1990aMICHALIK , 1990bSENDEK, BABCZYŃSKA-SENDEK 1990;ŚWIERCZYŃSKA 1990;DZWONKO, LOSTER 1992;MICHALIK, ZARZYCKI 1995;BĄBA 2003). The major therat for xerothermic plants is vegetation sucession.…”

Changes of species richness with special consideration of threatened species within the overgrowing xerothermic grassland in the forest clearing reserve of "Polana Polichno" in the Nida Basin (Małopolska Upland)

“…The consequence of the changes is not only the total rebuilding of species structure of a community but also strong depletion of species richness. Many papers show that species densities on such areas achieve 10 to 27 species per 0.01 m 2 and even exceed 40 species per 1 m 2 (3,12,22). Our observations confirm very high species densities in xerothermic grassland.…”

“…There are many hypotheses and theories that have been proposed to explain the high species diversity in such ecosystems (17). Ecologists try to find the mechanism of species existence through differentiated fertilization and management regime experiments (2,3,4,7,20,21,22) Another issue is the prevention of disappearance of the communities that exist due to very specific, permanent human impact (16,17). Cessation of the traditional agricultural use of the xerothermic grassland areas is the common phenomenon in the whole of Europe.…”