Russia is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world by area, covering over 17,125,191 square kilometres, and encompassing one-eighth of Earth's inhabitable landmass. Russia borders sixteen sovereign nations, the most of any country in the world. It is the ninth-most populous country with a population of 145.5 million.
Russia, owing to its gigantic size, has diverse ecosystems, including polar deserts, tundra, forest tundra, taiga, mixed and broadleaf forest, forest steppe, steppe, semi-desert, and subtropics. About half of Russia's territory is forested, and it has the world's largest forest reserves, which sequester some of the world's highest amounts of carbon dioxide.
Russian biodiversity includes 12,500 species of vascular plants, 2,200 species of bryophytes, about 3,000 species of lichens, 7,000–9,000 species of algae, and 20,000–25,000 species of fungi. Russian fauna is composed of 320 species of mammals, over 732 species of birds, 75 species of reptiles, about 30 species of amphibians, 343 species of freshwater fish, approximately 1,500 species of saltwater fishes, 9 species of cyclostomata, and approximately 100–150,000 invertebrates, Approximately 1,100 of rare and endangered plant and animal species are included in the Russian Red Data Book.
Russia's entirely natural ecosystems are conserved in nearly 15,000 specially protected natural territories of various statuses, occupying more than 10% of the country's total area. They include 45 biosphere reserves, 64 national parks, and 101 nature reserves. Russia still has many ecosystems which are still untouched by man; mainly in the northern taiga areas, and the subarctic tundra of Siberia. Russia had a Forest Landscape Integrity Index mean score of 9.02 in 2019, ranking 10th out of 172 countries; and the first ranked major nation globally.