Biomes Large geographical areas characterized by a certain type of climax community Terrestrial biomes • Temperature and rainfall are the major limiting factors that determine the type of climax community found in a given area – a limiting factor will influence what type of organisms can survive in an environment tundra • Very cold winters and brief growing seasons • Permafrost – permanently frozen subsoil • Flora lichens, mosses grasses • Fauna insects, migratory birds, large migratory animals Taiga • Long, cold winters but longer growing seasons • Flora coniferous forests – Pine trees, spruce trees, fir trees • Fauna large variety of small mammals, moose and black bear Temperate deciduous forest • Mild winters and long growing seasons • Flora angiosperms – Trees lose leaves in the fall – Oak, maple, elm trees • Fauna large diversity of small mammals – Grey squirrel, fox, deer Tropical rain forest • Warm all year – Receives 100-400 inches of rain per year • Flora many varieties of broadleaved plants, bamboo, ferns • Fauna many animal species, monkeys, snakes, leopard Grassland • Less than 20 inches of rain per year • Flora annual plants and grasses • Fauna deer, antelope, small mammals, prairie dogs Desert • Less than 10 inches of rain per year • Flora succulents, cactus and aloe • Fauna birds, reptiles, insects Marine biomes Based on three physical criteria • The marine biome covers 70% of the earth’s surface • Oceans absorb solar heat energy • Oceans have a stabilizing effect on average temperature of land areas • MOST PHOTOSYNTHESIS TAKES PLACE IN THE OCEAN! • There is a great variety of life forms in the ocean • Organisms that live on the ocean floor are called BENTHOS • Photosynthetic organisms are called PHYTOPLANKTON • These are the producers in the marine biome • Small organisms that float near the surface are PLANKTON – these are protists and algae, larvae of various animals, small jellyfish, worms Distance from shore • Intertidal zone – where land meets water • Nertic zone – shallow regions over the continental shelf • Oceanic zone – the sea floor Water depth • Pelagic zone – open water of any depth • Benthic zone – the sea floor Freshwater biome • These can be divided into two types 1) Standing water lakes, ponds, swamps and bogs 2) Running water streams • Lakes are usually larger than ponds • Lakes are so deep that light does not reach the bottom in all parts • Ponds are shallow enough for light to reach the bottom • Cattails and other plants grow around the surface of the lake and in the pond • Streams are fast moving water • The bottom is made of rocks and gravel • Organisms can be found in calmer, shallow areas near stream banks • Swamps are low, wetland areas • Fresh and saltwater swamps are often called wetlands • Wetlands are important nesting sites for water birds