In this article we present the spatial distribution of plant communities from the north-eastern slope of the Vlădeasa massif, mapped at a 1: 25000 scale, the most important environmental factors involved in the determination of the structural variability of grassland, as well as the relationship between their structure and socioeconomic activities. The results from the canonical correspondence analysis (CCA) identify the presence of water and nitrogen in the soil as the main factors involved in the determination of the pastures’ eco-coenotic variability. Nitrogen content in the soil is directly influenced by socio-economic activities, respectively by the different use of the fields (pastures or hay meadows). As a result, the phytodiversity of plant communities is influenced by their management. The highest phytodiversity is that of the Poo-Trisetetum flavescentis association, which is maintained artificially by traditional land use (periodical fertilization), depending on the quantity of hay that is needed, while the lowest phytodiversity is that of the Violo declinatae-Nardetum association, used as a pasture.