Summer is very short; it has about 45 to 100 days at most, and in a lot of places, the temperatures can go below freezing (32 °F or 0 °C) at any time of the year, even in the summer. Vegetation (plants) in a subarctic climate usually has low diversity (only a few different types of plants grow), because only "hardy" (very tough) species can survive the long winters and make use of the short summers. Trees are mostly evergreen conifers, because few "broadleaved" (big leaves) trees can survive the very low temperatures in winter. This type of forest is also known as taiga. The word "taiga" can also be a name for the climate itself. A lot of plants grow in the taiga (even if there are only a few different kinds of plants), so the taiga (boreal) forest is the largest forest biome on the planet, with most of the forests in Russia and Canada.