Azerbaijan is a country in the South Caucasus region, situated at the crossroads of Southwest Asia and Southeastern Europe. It is bound by the Caspian Sea to the east, Russia to the north, Georgia to the northwest, Armenia to the west and Iran to the south. Three physical features dominate Azerbaijan: the Caspian Sea, whose shoreline forms a natural boundary to the east; the Greater Caucasus mountain range to the north; and the extensive flatlands at the country's center. There are also three mountain ranges, the Greater and Lesser Caucasus, and the Talysh Mountains, which together cover approximately 40% of the country. Nine out of 11 existing climate zones are present in Azerbaijan. Nearly half of all the mud volcanoes on Earth are concentrated in Azerbaijan. Azerbaijan's flora consists of more than 4,500 species of higher plants. Due to the unique climate in Azerbaijan, about 67 percent of the species growing in the whole Caucasus can be found in Azerbaijan. Since the independence of Azerbaijan in 1991, the Azerbaijani government has taken drastic measures to preserve the environment of Azerbaijan. But national protection of the environment started to truly improve after 2001 when the state budget increased due to new revenues provided by the Baku-Tbilisi-Ceyhan pipeline. Within four years, protected areas doubled and now make up eight percent of the country's territory. Since 2001, the government has set up seven large reserves and almost doubled the sector of the budget earmarked for environmental protection.