What is ecology and what it studies. The biosphere. The ecosystem: structure, functions and processes. The flow of energy, primary productivity, decomposition and global production-decomposition balance. Trophic chains and nets, trophic levels and structure. Auxiliary natural and human energy and related environmental problems. The biogeochemical cycle of materials, alteration of the cycles in the local and larger scale, with possible remedies and management processes. Elements of the biotic community: diversity of species and habitats, ecological succession with relative problems and possible management approaches. Biogeography of Islands and environmental fragmentation with elements of its definition and management. Population dynamic. Relationships among living organisms.