The impact of intensive sheep grazing in the spring on the vegetation of xerothermic grasslands in Stawska Góra nature reserve

Abstract

The aim of study was to assess the impact of intensive sheep grazing in the spring on the vegetation of xerothermic grasslands in Stawska Gora nature reserve, particularly the Carlina onopordifolia seedling development and preferences concerning the ingestion of specific plant species, including shrubs and tree-understory. In May 2015, 40 specimens of the Świniarka Sheep and Polish Lowland Sheep were grazed in an area of 1.85 ha. Phytosociological releves were taken using the Braun-Blanquet method. Changes in the plant cover were assessed in July 2015 under grazing and non-grazing conditions. The flowery grassland plants were assigned to the Cirsio-Brachypodion pinnati alliance and thicket communities - to the Rhamno-Prunetea class. There was confirmed that community under study is distinguished by a large share of Carlina onopordifolia . The number of Carlina onopordifolia seedlings in the grazed areas was significantly greater than in the non-grazed areas. The sheep ingested all herbaceous plants appearing in the grasslands in May, except for the poisonous Adonis vernalis and most of shrubs. Preliminary research results indicate that grazing in the spring led to a decreased cover-abundance of Brachypodium pinnatum and some shrubs, and also - to smaller share of dead organic matter in the plant cover. It can create favourable conditions for the generative reproduction of xerothermic plants such as Carlina onopordifolia .