The textbook examines the entire range of issues of general (biological) ecology: history, ecology of species (autechology - environmental factors, adaptations of organisms, life strategies), population ecology (characteristics of populations, their dynamics and relationships), ecology of ecosystems (functional structure , energy flows, diversity of ecosystems and their dynamics), biosphere (structure and cycles of the main nutrients, noosphere). For students of higher educational institutions studying in the following areas and specialties: “Ecology”, “Biology”, “Medicine”, “Agriculture” . Of interest to scientists in the fields of biology, ecology, forestry and agriculture.