Chapter 6 Biomes

Section 1 What is a Biome?

Biome A biome is a large region characterized by a specific type of climate and certain types of plants and animal communities.

Biomes and Vegetation Biomes described by vegetation because they are the most noticeable characteristics. Plants determine organisms that can live there. Plants have adaptations to allow them to survive. Cacti conserve and retain water.

Biomes and Climate Climate refers to the weather conditions, such as temperature, precipitation, humidity, and winds, in an area over a long period of time. Temperature and Precipitation Biomes where rainfall is not frequent – cacti and desert shrubs Biomes with rainfall – large trees Latitude and Altitude Latitude – the distance north or south of the equator Altitude – height of an object above sea level As both increase, biomes and vegetation change Rainforests – close to equator

Section 2 Forest Biomes

Tropical Rain Forests Located in a belt around the Earth near the equator. Help regulate world climate and play vital roles in the nitrogen, oxygen, and carbon cycles. Always humid and warm

Tropical Rain Forests Nutrients Most nutrients in the plants, not in the soil. Organic matter decays quickly in hot, wet conditions. Plants quickly take up nutrients. Removed so efficiently that water running out of the soil may be as clear as distilled water.

Tropical Rain Forests Layers Emergent Layer – tallest trees. Trees emerge into direct sunlight. Canopy – Primary layer of rain forest. Trees can grow to more than 90 feet. Lower canopy – receives less light. Epiphytes, organisms that grow on tall trees, live here. Orchid Understory – very little light Many of our house plant are native to tropical rain forests. Because they adapted to low levels of light, they are able to grow indoors.

Wreathed Hornbill Collared Anteater Orchid Costa Rican Mantis

Threats to the Rain Forests Habitat Destruction – occurs when land inhabited by an organism is destroyed or altered. Every minute – 100 acres of rain forest cleared Exotic Pet Trading Illegally trapping animals and selling at high prices Planet in Peril

Temperate Forests Temperate rain forests - occur in North America, Australia, and New Zealand. Olympic National Park – Washington state Large amount of precipitation, high humidity, and moderate temperatures.

Temperate Deciduous Forests Trees drop their broad, flat leaves each fall. Located between 30 degrees and 50 degrees north latitudes. Temperature and vegetation changes Plants Maple, Oak, small shrubs, ferns, mosses Animals Squirrels, bears, grasshoppers, deer Many birds are migratory – fly south to warmer weather and more food.

Taiga Northern coniferous forest that stretches in a broad band across the Northern Hemisphere just below the Arctic Circle Plants Conifer – tree with needle-shaped leaves and seeds that develop in cones Animals Snowshoe hares, lynx, wolves

Section 3 Grasslands, Desert, and Tundra Biomes

Savannas A tropical biome dominated by grasses, shrubs, and small trees Rain falls mainly during wet season (summer) & dry season (winter), which last for only a few months of the year. Animals Elephants, giraffe, cheetah, lion, hyena

Temperate Grasslands Cover large areas of the interior continents, where there is moderate rainfall, but still too little for trees to grow. Plants Grasses and wildflowers – roots form dense layers to survive drought and fire Animals Pronghorn antelope, bison, prairie dogs Threats – farming and overgrazing

Chaparral A temperate shrubland biome that is found in all five parts of the world with a Mediterranean climate. Moderately dry, coastal climate, with little or no rain in summer Plants Low-lying, evergreen shrubs and small trees So well adapted to fire that they can resprout from small bits of surviving plant tissue. Animals Quail, lizards, chipmunk, mule deer – brownish-gray to blend in with brush Threats Human development (for commercial and residential use)

Desert Areas that have widely scattered vegetation and receive very little rain. Plants Succulents – cacti– thick, fleshy stems and leaves that store water. Spines on cacti keep thirsty animals from devouring plant Animals Gila monsters, rattlesnakes

Tundra Located in northern arctic regions Winter too cold and dry to permit growth of trees. Permafrost – deeper layers of soil that are permanently frozen throughout the year. Vegetation Mosses and lichens – plants that grow close to the ground Animals Caribou, wolves, moose, arctic foxes Threats Oil exploration disrupts habitats of plants and animals