Biomes (APES)

Climate

The average weather conditions in an area over a long period of time.

Climate is the main factor in determining which plants can grow in a certain area, which in turn defines the biome.

Temperature and precipitation are the two most important factors that determine a region's climate.

Temperature and Precipitation

As precipitation decreases in an area the diversity of the species in the area decreases.

Latitude

The distance north or south from the equator

Altitude

The height of an object above a reference point, such as sea level or the Earth's surface.

Temperate Rain Forests

Where : They occur in North America, Australia, and New Zealand

Precipitation : Large amounts of rain

Temperature : Cool

Plants : Dominated by evergreen trees such as firs and spruces

Tree branches are draped with mosses, tree trunks are covered with lichens, and the forest floor is covered with ferns

Soil : Rich, wet soils

Windward

The front side of a mountain that receives wind and moisture

Leeward

The backside of a mountain where the rain shadow occurs

Rain Shadow

The dry area on the leeward of a mountain. Rain shadow occurs because the mountain blocks rain-producing weather systems from passing over the mountain

Temperate Deciduous Forest

Where : Located between 30 degrees and 50 degrees north latitude

Precipitation : They receive 75 cm to 125 cm of precipitation annually

Temperature : The range of temperatures can be extreme, with very hot summers and winters temperatures below freezing.

Plants : Forests characterized by trees that shed their leaves in the fall

Tall trees, dominate the canopy

Shrubs cover the understory

More light reaches deciduous forest floors than rain forest floors

Adaptations to survive seasonal changes

Trees shed their leaves and seeds go dormant under the insulation of the soil

Soil : The precipitation helps to decompose dead organic matter contributing to rich soil of the forest. Good for agriculture.

Tropical Rain Forests

Where : Forests or jungles near the equator

Precipitation : Large amounts of rain

Temperature : Strong sunlight allows the rain forest to stay warm with little variation in temperature

Biodiversity : Greatest known diversity of organisms on Earth. Ideal for a wide variety of plants and animals

Tropical Rain forests help to regulate world climate

Plays vital roles in nitrogen, oxygen, and carbon cycles

Have the greatest biodiversity than any other land biome

Soil : Nutrient poor

Most nutrients are within the plants

Decomposers on the rain forest floor break down dead organisms and return the nutrients to the soil, but plants quickly absorb the nutrients

Nutrients are removed do efficiently that runoff from rain forests is often as pure as distilled water

Soil cannot support agricultural crops for more than a few years

Many trees have ground roots called buttresses that grow sideways from the tree to provide it with extra support in the thin soil

Layers of the Rain Forest

The canopy is the layer s of treetops that shade the forest floor

Epiphytes are plants that use another plant for support but not for nourishment, and are located on high trees in the canopy

Growing on tall trees allows them to reach the sunlight needed for photosynthesis, and to absorb the water and nutrients that run down the trees when it rains

The understory is shaded by the main canopy of the forest

Only trees and shrubs adapted for shade can grow there

Herbs have flat leaves to capture the small amount of light available

Risks :

Every minute of every day, nearly 150 acres of tropical rain forest are cleared for logging operations, agriculture, and oil exploration

Exotic-pet trading robs the rain forests of rare and valuable animal species only found there

Habitat destruction increases risk of extinction in species

Taiga

Where : Region of evergreen, coniferous forest below arctic and subarctic tundra regions

Precipitation : Precipitation varies, with larger amounts during the summer

Temperature : Long winters and little precipitation. Nearly constant daylight during the summer

The growing season can be as short as 50 days. Most plant growth occurs during the summer.

Plants : Evergreen coniferous forest

A conifer is a tree that has seeds that develop cones

Their leaves have an arrow shape and waxy coating that helps them to retain water in the winter

The conifer's shape helps the tree sheds snow to the ground and not get weighed down.

Biodiversity : The taiga has many lakes and swamps in the summer. This :

Attracts birds that feed on insects during the summer

Year round residents such as shrews, burrow underground for better insulation

Soil : Forms slowly in the taiga because the climate and acidity slow decomposition of organic matter

Conifer needles make the soil acidic when they fall to the ground

Preventing plants to grow on the forest floor

Risks : Agriculture, building, housing

Temperate Grasslands

Where : Temperate grasslands are located on the interiors of continents where too little rain falls for trees to grow and include the prairies of North America

Precipitation : Rainfall is intermediate between that of a forest and desert

Mountains block rain clouds from the west maintaining grasslands

Rainfall increases eastward, allowing grasses to grow taller

Temperature : Hot summers and cold winters

Hot temperatures in the summer make the grasslands susceptible to fires

Biodiversity : Grazing animals, such as the bison and pronghorn antelope, have large, flat teeth for chewing the coarse prairie grasses

Grassland animals, such as prairie dogs, owls, and badgers, live in burrows that protect them from predators on the open grasslands

Soil : Most fertile soil of any biome

Few natural temperate grasslands remain because many have been replaced by :

Grazing areas

Farms growing corn, soybeans, and wheat

Plants : Dominated by grasses, with few trees

The roots system form dense layers that survive drought and fire

Few trees survive on the grasslands because of the lack of rainfall, frequent fires, and the constant winds

Risks : Agriculture ; soil erosion

Savannahs and Tropical Seasonal Forests

Where : Savannas are plains full of grasses found in tropical and subtropical habitats, such as East Africa and Western India

Precipitation : Dry climate with wet season and dry season. Dry season can be very dry

Temperature : Warm/Hot

Plants : Grasses and scattered trees and shrubs

Special Adaptations

Grasses

Have coarse vertical leaves that expose less surface are to decrease evaporation

Trees

Some shed their leaves (save water)

Plants

Some plants have large horizontal root systems to help them survive the dry season

These roots also enable the plant to grow quickly after a fire

Almost all have thorns to protect themselves from herbivores

Biodiversity : Many animals are only active during the wet season

Special Adaptations

Grazing herbivores, like the elephant, have migratory ways of life

They follow the rains to areas of new grass and fresh watering holes

Predators often stalk these animals for food

Many animals only give birth during the wet season

Food is abundant

Young are more likely to survive

To reduce competition, herbivores eat vegetation of different heights than other species

Soil : Fire helps to restore nutrients to the soil during the dry season. Soil is fertile

Risks : Poaching

Chaparral

Where : Chaparrals are temperate woodland biomes located in the middle latitudes, about 30 degrees north and south of the equator

Chaparrals are located primarily in coastal areas that have Mediterranean climates

Precipitation : Dry summers and wet winters

Temperature : Hot summers, and mild winters

Biodiversity : A common adaptation is camouflage

Plants : Most chaparral plants are low-lying, evergreen shrubs and small trees that tend to grow in dense patches

Examples : manzanita, scrub oak, and herbs like sage and bay

Plants have small, leathery leaves containing oils that promote burning

Allowing natural fires to destroy competing trees

Chaparral plants are well adapted to fire

Soil : Not very fertile ; sandy doesn't hold water very well

Risks : Human development

Humans develop here because chaparrals get a lot of sun, are near the oceans, and have a mild year round climate

Desert

Where : Many are located near mountain ranges because mountains can block the passage of moisture-filled clouds, limiting precipitation

Precipitation : Long periods without rain, forming the driest places on Earth

Temperature : Extreme temperatures, there are hot and cold deserts

Plants : Little or no vegetation in many areas

Must contain adaptations for obtaining and conserving water

Many plant roots spread out just under the surface to absorb as much rain as possible

Succulents, such as cacti, have :

Thick, fleshy stems and leaves that conserve water

Animals : Have adaptations to prevent water loss

Reptiles have thick, scaly skin that prevents water loss

Amphibians survive by estivating burying themselves in the ground and sleeping through the dry season

Insects are covered with waterproof body armor that helps them retain water

Mammals have very efficient kidneys to reabsorb water

Most desert animals are nocturnal, because it is cooler

Tundra

Where : The tundra is a treeless plain that is located in the Arctic or Antarctic

Precipitation : High in summer

Temperatures : Very low winter temperatures, with short, cool summers

Soil : Only the top few centimeters will thaw

Permafrost is the permanently frozen layer of soil or subsoil

Plants : Lichens, mosses, and perennial herbs

Mosses and lichens can grow without soil

Many plants have wide roots to help anchor them against the icy winds

Most flowering plants are short

Keeps them out of the wind and helps them absorb heat from the sunlit soil

Woody plants and perennials have evolved dwarf forms

Animals : Millions of migratory birds fly to the tundra to breed in the summer when food is abundant

Caribou migrate throughout the tundra in search of food and water

Predators such as wolves prey on migratory caribou, deer, and moose

Rodents stay active, but burrow underground to avoid cold

Year-round residents, such as arctic foxes, lose their brown summer coat for white fur that camouflages them with the snow

Risks : Tundra is the most fragile biome of all biomes on the planet

The food webs are relatively simple

They are easily disrupted

One extinction can be catastrophic for many other species

Oil was located in parts of the tundra, and oil exploration, and transport has disrupted many tundra habitats

Pollution caused by spills or leaks of oil and other toxic materials may poison the food and water sources of organisms of the tundra