Biomes

Biome a large group of ecosystems that share the same type of climax community

2 Types of Biomes Terrestrial (land) Biomes Aquatic (water) Biomes marine (salt water) freshwater biomes

6 Major Terrestrial (Land) Biomes terrestrial biomes are defined by their latitude, altitude, and precipitation

Terrestrial Biomes tundra taiga dessert grasslands temperate forest tropical rain forest

Tundra treeless area around the poles temperatures rise above freezing only for very short periods of time, about 12 cm precipitation annually

Tundra soil is lacking in nutrients; topsoil is thin -little decay occurs soil supports only shallow-rooted grasses and small plants short growing season-limiting factor for life contains permafrost - layer of permanently frozen ground

Taiga called northern conifer forest climate is harsh - long, severe winters, short, mild summers, 35-40 cm precipitation annually permafrost is usually absent found in Canada, Northern Europe, Asia

Taiga Flora/Fauna: lichens, mosses, grasses, dwarf shrubs, cushion plants, mosquitoes, other biting insects, lemming, weasels, arctic foxes, snowshoe hares, snowy owls, hawks, musk-oxen, caribou, reindeer

Taiga topsoil is acidic and poor in minerals Example Organisms: mixed pine, fir, hemlock, & spruce trees, more large species of animals- caribou, moose, lynx

Desert Driest of the biomes, less than 25 cm of precipitation annually Located south of the taiga Atacama Desert in Chile – world’s driest place

Desert an arid region with sparse to almost nonexistent plant life desert plants sometimes have spines, thorns, or poisons that act to discourage herbivores example organisms - shrub, mesquite trees, cacti, kangaroo rat, pronghorn antelopes, foxes, coyotes, hawks, owls, roadrunners, snakes, lizards, scorpions

Grassland receives between 25 and 75 cm of precipitation annually soils have considerable humus content usually experience a dry season where insufficient water exists to support forests example organisms - more than 100 different species per acre, large herds of grazing animals, bison, buffalo, wolves, coyotes, prairie dogs, foxes, ferrets, birds, insects, reptiles, tortoises, lizards, snakes

large communities covered with grasses and similar small plants known as prairies (U.S., Canada, & Australia), steppes (Russia), savanna (Africa), pampas (Argentina) called the breadbaskets of the world-ideal for growing grains (oats, rye, wheat) occupies more area than any other terrestrial biome Grassland

Temperate Forest soil consists of top layer rich in humus and a deeper layer of clay example organisms - squirrels, mice, rabbits, birds, black bears, deer, salamanders, opossums

Temperate Forest precipitation ranges from 70-150 cm annually deciduous forests - dominated by broad-leaved hardwood trees that lose their foliage annually (deciduous)

Tropical Rain Forest most biologically diverse of the terrestrial biomes, located in the equatorial regions around the world uniformly warm (25oC) , wet weather dominated by lush plant growth, annual rainfall is at least 200cm up to 400 cm, which much of is retained and recycled by the heavy canopy of leaves

Tropical Rain Forest most organisms live in the trees more species of reptiles, amphibians, and birds are found here than any other terrestrial biome 3 million species of insects in the tropical rain forest, butterflies, gorillas, cougars Nutrients from decay must be absorbed quickly. Why? Due the large amount of rain

Precipitation Amounts 1 cm = 0.4 inches

Marine Biomes oceans contain the largest amount of biomass (living material) of any biome on Earth most of this biomass is plankton - microscopic organisms that float in the layers of the photic zone

Water Zones photic zone - more shallow, sunlit zone aphotic zone - deeper water that never receives sunlight

Mixed Waters all waters flow to a sea/ocean estuary – coastal body of water partially surrounded by land where saltwater and freshwater mix

Tides caused by the gravitational pull of the sun and moon – twice a day intertidal zone – area between the high and low tide lines

Photic Zone rainfall washes nutrients from land into the waters high in nutrients and abundant in life plankton – small organisms that live in waters of the photic zone – base of all aquatic food chains

Aphotic Zone intense pressure no light animals are adapted for darkness and scarcity of food

Freshwater Biome ponds, rivers, and lakes temperature varies with depth – abiotic factor that limits the kind of organisms that can survive in a deep lake light also is a limiting abiotic factor