The document discusses the elements of ecosystems in three types of forests: Mediterranean forests, Atlantic forests, and forests of the Canary Islands. It examines the biotope, biocenosis, and interactions for each forest ecosystem. It also provides information on the ecosphere and biosphere, defining the ecosphere as the area around a star suitable for life and noting Earth and Mars comprise our solar system's ecosphere, and the biosphere as all living things on Earth inhabiting the troposphere, hydrosphere, and upper geosphere.