Earth’s Biomes Content Standard 15: Identify biomes based on environmental factors & native organisms.

Earth’s Biomes All organisms interact with living & nonliving things in their environment. Because the environment is so complex, scientists divide it into different regions. These regions are determined largely by their abiotic factors. Soil composition Amount of light, water & inorganic nutrients Altitude (height above sea level) Latitude (distance from the equator) Climate (long-term weather pattern in an area, including average high & low temperatures & amounts & types of precipitation)

Biomes The major ecosystems of Earth are called biomes. A biome covers a wide area & is characterized by specific physical conditions & types of organisms. The 6 major biomes on land are characterized by their climate, latitude, altitude, & proximity to water, including oceans, lakes & rivers.

Regardless of their actual location, similar biomes around the globe have similar groups of organisms that possess similar adaptations to the environment.

Biomes The major terrestrial biomes are tundra, deserts, tropical rain forests, grasslands, taiga (coniferous forests), & temperate deciduous forests. Each of these terrestrial biomes is characterized by a set of abiotic factors & a unique community of organisms. 2 key abiotic factors that define each biome are its average annual amount of precipitation & its temperature range over the course of the year.

Average Yearly Precipitation (in) Yearly Temperature Range (°F) Biome Average Yearly Precipitation (in) Yearly Temperature Range (°F) Tundra 6 - 10 -29 – 54 Desert <10 28 – 120 Tropical Rain Forest >80 68 – 95 Grassland 20 - 35 -40 – 100 Taiga (Coniferous Forest) 16 – 40 -22 – 86 Temperate Deciduous Forest 30 – 60

Terrestrial Biomes: Tundra The tundra is a cold, dry biome that receives an average of 15 to 25 cm (6 to 10 in) of precipitation (mostly snow or ice) each year. The tundra is located in the Arctic & Antarctic regions & at the tops of high mountains in temperate zones. A defining feature of the tundra is permafrost, a layer of permanently frozen subsoil.

The Tundra Biome

Tundra Vegetation

Terrestrial Biomes: Tundra Summers are short & cool; winters are long, cold, & usually dark. Tundra plants display stunted growth due to the freezing of the topsoil, harsh winds, cold, & a short growing season. Tundra animals include migratory birds, musk oxen, Arctic foxes, & caribou. Many of these animals have fur that changes from brown in summer to white in winter to help them blend with their surroundings & avoid predators.

Arctic Hare in Summer & Winter

Terrestrial Biome: Desert The desert is characterized by very dry conditions and less than 25 cm (10 in) of precipitation each year. Desert soils are mineral rich but contain little organic matter. Deserts can be hot, cold, or very variable in their temperatures. Desert organisms are adapted to temperature extremes & to temperatures that may vary by more than 19°C (66°F) on a daily basis.

Deserts are located in Africa, Asia, the Middle East, North & South America, & Antarctica.

Terrestrial Biome: Desert Most desert plants are adapted for storing water. Snakes, lizards, jackrabbits, & rodents are common animals in hot deserts. Many of these are active only at night when temperatures are cooler. Some burrow into the ground during daylight hours to escape the hot sun.

Terrestrial Biome: Tropical Rain Forest The tropical rain forest has greater biodiversity than all other terrestrial biomes combined. A tropical rain forest is characterized by nutrient-poor soils, warm year-round temperatures, & average yearly precipitation of 200 to 400 cm (80 to 160 inches) in the form of rain or mist.

Terrestrial Biome: Tropical Rain Forest Trees in the tropical rain forest are very tall & form a dense covering called the canopy that shades the lower layers.

Tropical rain forests are located near the equator in South & Central America, southeastern Asia, Africa, southern India, & northern Australia.

Terrestrial Biomes: Grasslands Grasslands have warm to hot summers & cool to cold winters & receive 50 to 90 cm (20 to 35 in) of precipitation each year. Precipitation in this biome is seasonal, occurring mostly in the spring & fall. Soils are rich in nutrients & organic matter. Much of this organic matter is found in a thick layer of topsoil located at the soil surface.

Grasslands are located in central Asia, N Grasslands are located in central Asia, N. America, Australia, central Europe, Africa, & S. America.

Terrestrial Biomes: Grasslands Plants include numerous grasses & herbs. Animals include coyotes, badgers, mule deer, rabbits, prairie dogs, bison, & many birds & insects.

Terrestrial Biomes: Temperate Deciduous Forests Temperate deciduous forests are characterized by broad-leafed trees that shed their leaves in the fall & sprout them in the spring. Rainfall & temperatures are moderate. This causes rapid decomposition of organic matter. This results in soil that is rich in both nutrients & organic matter.

Deciduous forests are located in N. America, Europe & Asia.

Typical animals of these regions include foxes, squirrels, raccoons, deer, turtles, a wide variety of birds, and insects. Fungi are also common in this biome.

Terrestrial Biomes: Taiga The taiga is a cold to cool, moderately wet biome that is located in the northern parts of N. America, Europe, & Asia.

Terrestrial Biomes: Taiga The taiga is sometimes called the coniferous forest biome because of the cone-bearing (coniferous) trees that cover its landscape. Soils in the taiga tend to be acidic. In addition to coniferous trees, mosses thrive in the acidic soil of this biome.

Typical animals of this biome include black bears, moose, elk, deer, wolves, squirrels, and a variety of insects.

Terrestrial Biomes: Wetlands A wetland is a land ecosystem in which water covers the soil or is present near the soil surface for at least part of the year. Wetlands are a cross between a terrestrial ecosystem & an aquatic ecosystem & can have either moving or standing water. Wetlands serve as breeding grounds for many species of birds, fish, amphibians, insects, & other animals.

Terrestrial Biomes: Wetlands Freshwater wetlands include bogs, swamps, & marshes. In addition to providing habitat for many species, wetlands serve an important role in helping to cleanse & purify water that moves through the environment.

Aquatic Biomes Aquatic ecosystems are defined by their salinity, chemistry, depth, flow, & water temperature. Salinity is used to divide aquatic biomes into 2 large groups: freshwater biomes & marine biomes. As its name implies, a freshwater biome is an aquatic ecosystem whose primary feature is freshwater. The marine biome is an aquatic biome whose main feature is salt water.

Aquatic Biomes: Freshwater Two main types of freshwater biomes are flowing-water ecosystems & standing-water ecosystems. Flowing-water ecosystems include rivers, streams, creeks, & brooks. Organisms that live in these ecosystems are adapted to seasonal changes in water level & rate of flow. Standing-water ecosystems include lakes & ponds. Water generally flows into & out of these ecosystems & circulates within them. The standing water of these ecosystem provides habitat for many different organisms.

Aquatic Biomes: Marine Marine biomes are defined by water that is high in salt content. They vary in their distance from the shore & in the depth of the water. Unique communities of organisms, such as the intertidal organisms found on beaches, live at the edges of marine ecosystems. Water depth affects pressure & the amount of light that penetrates the water.

Moving from the shore toward the open ocean, marine ecosystems include the intertidal zone, the coastal (neritic ocean), and the open ocean.

Aquatic Biomes: Marine Organisms that live in the intertidal zone are directly affected by the twice-daily rise & fall of the tide. Sometimes they are completely submerged in water; at other times they are exposed to the air & sunlight.

Aquatic Biomes: Marine Organisms in the coastal ocean live on the shallow shelf that extends from the low-tide line to the deep ocean. This region is known as the neritic zone. The neritic zone is shallow enough to allow sunlight to penetrate its water & reach the ocean bottom. The region is also shallow enough to keep the water pressure moderate.

Aquatic Biomes: Marine Coral reefs & kelp forests thrive in the neritic zone. These areas provide abundant resources such as food & shelter for other ocean-dwelling organisms. Most aquatic life lives in this ocean region.

Aquatic Biomes: Marine The deep ocean lies beyond the coastal shelves of the continents. The deep ocean covers about 60% of Earth’s surface. Although it covers the largest area, the deep ocean actually serves as home to the fewest ocean species. Organisms that live in the deepest parts of this region need to be adapted to a cold, dark, & extremely high-pressure environment.

Estuaries Estuaries are areas where freshwater meets the salty water of the sea. Estuaries contain brackish water—a mixture of freshwater & salt water. The concentration of salt in water can change frequently because of variations in rainfall, changes in ocean conditions such as waves, tides, & currents, & wind. Estuaries also have constantly changing water levels that are affected by the rise & fall of the ocean tides. 2 ecosystems that form in estuaries are salt marshes & mangrove swamps.

Salt Marsh

Mangrove Swamp

Which terrestrial biome is characterized by permafrost? River Desert Tundra Tropical Rain Forest

Which biome receives very little rainfall throughout the year & includes snakes, lizards, & jackrabbits as its characteristic animal species? Desert Temperate Deciduous Forest Taiga Tundra

What is the correct arrangement of ocean zones moving away from the shoreline? Benthic Zone → Neritic Zone → Intertidal Zone → Open Ocean Intertidal Zone → Open Ocean → Coastal Zone Intertidal Zone → Neritic Zone → Open Ocean Neritic Zone → Open Ocean → Intertidal Zone

Which of these is a freshwater biome? Tundra Estuary Ocean River

What land biome has the greatest variety of life? Tropical Rain Forest Desert Tundra Grassland

Alabama AHSGE Coach, Biology Triumph Learning, 2009 PowerPoint adapted from the Standard 15 (Lesson 20) lesson in the Coach book. Alabama AHSGE Coach, Biology Triumph Learning, 2009