V. Vateva, K. Stoeva
Abstract. The natural pasture grass associations are plant groups, whose composition, state and growth are result of complete showing native-climatic conditions. They are those grass associations, who ensure a valuable biomass for stock-breeding in the regions, where hi is basic occupation. Such regions in South-East Bulgaria are the Sakar and Strandzha. At least, soil-climatic conditions in the two regions are nearly and similar, the available pasture grass associations are diferent. During the three years period on the special selected and marked natural pasture grass associations of Sakar and Strandzha regions were carried out observations. The chosen pasture grass associations are with different locations and they are representative of the most typical and in a mass using pastures of two regions. The aim of the observations is to be done an comparative ecological analysis of the native pasture compositions in the Sakar and Strandzha regions. There composition and type belonging to be analyses, the changes in the pasture compositions to be study and the tendencyes for a future together development of two regions to be determine. As a result of the organize observations was established, that by the native-climatic conditions of the two regions, the pasture associations are differ on a type belonging. In the Sakar mountain are more pastures of type: Agrostis vulgaris – Festuca fallax; Cynodon dactylon – Lolium perenne; Andropogon schaemum and Festuca myuros – Bromus sp., and in the Strandzha the basic pasture associations are of the type: Hordeum crinitum – Trifolium nigrescens; Cynusurus cristatus – Lolium perenne – Trifolium subteraneum; Agrostis vulgaris – Cynusurus cristatus- Lolium perenne; Cynodon dactilon- Lolium perenne and Avena flavescens – Cynusurus cristatus – Lolium perenne. The changes who has come of the pasture compositions in the Sakar and Strandzha as a result of the climatic factors and the methods of use are in negative direction.