In this contribution arc presented results of the long-term production-ecological research of the forest ecosystems in the Malé Karpaty Mts. The aims of the research and characteristics of the complex ecological research of this region are discussed. The basic data about the herb, shrub and tree layer biomass and the organic litter fall biomass in mostly beech forests of the Malé Karpaty Mts as also the data about the total plant biomass and energetic values of the beech ecosystems are presented. Obtained results are the base for a real estimate of the potential productivity of beech ecosystems in the hill-land regions of Slovakia.