INFLUENCE OF DIFFERENT LEVELS OF INVASION WITH AMORPHA FRUTICOSA OF THE GRASSLAND VEGETATION ON SOME SOIL FEATURES

Abstract

Amorpha fruticosa L. (false indigo bush) is an invasive shrub species from Fabaceae family originating from North America. Nowadays this species creates great problems because it is invading floodplains along the rivers from Europe, even the Danube River floodplain reaching to the Danube Delta. The floodplain area of the river Mure? is highly affected by this invasion, this species occupying great surfaces of grassland and arable land. The researches were developed on the lowland area alongside the river Mure? (Arad County, western Romania) in the perimeter of the locality Pecica, respectively belonging to Mures Floodplain Natural Park. The purpose of the work was to characterize different relationships between the features of the grassland vegetation with soil features in three different situations, respectively permanent grassland, grassland totally invaded with A. fruticosa, and transitional grassland partially invaded with A. fruticosa. The soil samples were collected from 0 - 25 cm depth. The researches were investigated the influence of the false indigo bush invaded grassland on the soil features as pH, nitrogen index, total nitrogen, humus content, phosphorus, potassium and carbonates. The considered grassland vegetation features related with the soil features were: floristic composition (main functional groups of plants, some biodiversity indexes and pastoral value. The obtained results showed the existence of complex relationships among the analysed vegetation and soil features.