Humans also influence the carbon cycle indirectly by changing the terrestrial and oceanic biosphere. It exists at the interface of the lithosphere, atmosphere, hydrosphere and biosphere. Vernadsky defined ecology as the science of the biosphere. There is a large natural flux of into and out of the biosphere and oceans. "The biosphere" (1926), and described the fundamental principles of the biogeochemical cycles. The Escarpment is a UNESCO World Biosphere Reserve. Sea ice is part of the Earth's biosphere. Of the 175 species of orchids found in the Nilgiri Biosphere Reserve, eight are endemic. Bacterial life survives in the stratosphere, making it a part of the biosphere. Phosphorus forms parts of important life-sustaining molecules that are very common in the biosphere. The island is designated a UNESCO Biosphere Reserve. The period marked a steep change in the diversity and composition of Earth's biosphere. Agasthyamala Biosphere Reserve is listed in UNESCO's World Network of Biosphere Reserves. Velebit Nature Park is a part of the UNESCO Man and the Biosphere Programme. Moreover, Mount Vesuvius is part of the UNESCO World Network of Biosphere Reserves.