GEF

Unit 5  |  The Importance of Biodiversity 107 Essential Concept Biodiversity is an important feature of healthy, vibrant ecosystems. 5.1  Where Does Life Exist? Defining Earth’s Biosphere A biosphere is the parts of the land, sea, and atmosphere in which organisms are able to live. On Earth, that is mostly a thin layer on and above the planet’s surface and in water. The enormous diversity of habitats on Earth has given rise to an incredible range of species . While the total number of species remains controversial, scientists estimate that there are around 8.7 million species on Earth. Some researchers maintain that the total number of species may even be closer to 100 million. At present, only about 1.3 million species have been named and cataloged. What is certain, is that Earth supports an incredible amount of biodiversity, the total variation of life forms on the planet. Biodiversity is a key component of a sustainable planet, economy, and human society. Forest ecosystems are full of biodiversity. BIOSPHERE The parts of the land, sea, and atmosphere in which organisms are able to live. SPECIES A group of organisms that is able to reproduce, producing fertile offspring. BIODIVERSITY The range of species and habitats that make up life on planet Earth.