PRINCIPLES OF ECOLOGY BIOMES Each biome is defined by a unique set of abiotic factors — particularly climate — and a diverse group of plants and animals. Biome — large group of ecosystems that shares the same type of climax community. Biomes located on land are terrestrial biomes. Biomes located in bodies of water are known as aquatic biomes. Aquatic Biomes Water makes up the largest part of the biosphere covering approximately 75 percent of Earth’s surface. The aquatic biome can be broken down into two basic regions — freshwater and marine. Freshwater Has low salt concentration — usually less than 1 percent (ponds & lakes, streams & rivers, wetlands) Marine Cover about ¾ of Earth’s surface and includes oceans, coral reefs, and estuaries. Terrestrial Biomes Terrestrial biomes vary greatly. Climate is a group of abiotic factors that influence the type of climax community that develops in area. The most common terrestrial biomes that result from climate differences are tundra, taigas, deserts, savannahs, temperate forests and tropical rainforests. Tundra In physical geography, tundra is a type of biome where the tree growth is hindered by low temperatures and short growing seasons. Taigas Taiga, generally referred to in North America as boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches. The taiga or boreal forest is the world's largest land biome. Savanna A savanna or savannah is a mixed woodland-grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Temperate forest is a forest found between the tropical and boreal regions, located in the temperate zone. It is within the second largest biome on the planet, covering 25% of the world's forest area, only behind the boreal forest, which covers about 33%. Tropical rainforests Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as lowland equatorial evergreen rainforest.
