The Biosphere: A Summary

AP BiologySpring 2011

Climates vary based on wind and ocean currents Climate: is based on the amount of sunlight,

elevation, and proximity of land and seas

Areas nearest to the equator are exposed to the most sunlight Due to the fact that particles and greenhouse

gases reflect some sunlight back to earth Also energy is spread out over a smaller

surface of the area

• These changes in surface temperature causes air current patterns– Warm air rises, collects water and rains north

and south of equator– Dry cool air descends at around 30 degrees

latitude, where deserts are often located – At around 60 degrees latitude, moisture is

again released– At poles, air again lowers and does not contain

much water– When water travels over land, it rises and falls

more quickly than it does over water

Many energy sources utilize the wind or solar energy These energy forms could substitute for non-

renewable energy formsSolar energy can store the energy directly from

the sun Wind turbines can create energy from the

power of winds

Ozone layer: is a protective layer around the earth that protects us from UV rays In 1980’s, scientists

discovered a hole in the ozone layer

Hole was caused by chlorofluorocarbons (CHC’s)

Harmful UV rays cause a higher incidence of skin cancers and cataracts

Smog: is mixture of air pollutants that are caught in an air inversion Factories and emissions from vehicles are

major cause

Acid rain: is when pH of rainwater is too acidic Acidity is caused by sulfur dioxides and

nitrogen oxides primarily from automobiles and factories

Acid rain can harm statues, buildings, plants, and animals

Particles in the air resulting from pollution can cause respiratory ailments

The ocean at the equator is approximately 8cm higher than at the poles This difference in elevation moves the water

towards the poles Other influences on ocean currents are wind,

the rotation of the earth and topography The Gulf Stream is a major current along the

eastern coast of the US

A rain shadow indicates that after air rises and cools over mountains, it rains on one side of the mountain and leaves the side away from the wind fairly dry

A monsoon occurs in areas north or south of seas and creates an intensely windy storm

The earth is divided into 6 biogeographical realms that house specific species of plants and animals These biogeographic realms are subdivided

into smaller divisions called biomesBiomes are usually defined by having similar

climates and distribution of species Some biomes can be remnants of single land

masses on Pangea that separated

Various biomes can have different soil types

Surface litter: first component of soil that is observed, followed by topsoil

Topsoil: most important layer of soil for plant growth Little topsoil in

deserts and rain forests

Topsoil is thickest in grasslands, so they can make an easy conversion to farmland

Deserts: receive less than 10cm of rainfall yearly and are usually around 30 degrees north and south latitudePlant life is adapted to poor rainfall due to waxy

cuticle and active stomata Ex. Cacti, mesquite bushes

Animals include bats, kangaroo rats

Grasslands: receive more rainfall than deserts, but not as much as forests (around 25-100cm)Characterized by periods of drought, winds,

and occasional fires Plants include shortgrass and tallgrass prairieAnimals include bison, zebra, elephants,

wildebeest

Dry shrublands: receive between 25-60cm of annual rainfall and are prone to fires Plants in this biome are adapted to recover

easily from firesDry woodlands: receive between 40-100cm

of annual rainfallTrees may be found, but they do not provide a

solid canopy

Semi-evergreen forests: are found in southeast Asia and IndiaContain both deciduous broadleaf trees and

those that keep their leaves

Tropical deciduous forests: have scarce rainfall and trees that shed their leaves in the dry season

Temperate deciduous forests: have between 50-150cm of annual rainfallIn this biome, trees are deciduous and dormant

in the wintertime

Evergreen broadleaf forests: located between 10 degrees north and south Rainfall here is between 130-200cm per year

and humidity is highA dense canopy is formed of trees, vines and

epiphytes

Rapid deforestation is taking place in the tropical rain forestsThis area of world houses great biodiversity of

plants and animalsSome medicines and food products are from

this region Rain forest contribute lots of oxygen to the

atmosphere

Biome contains many evergreen trees with adaptations to converse waterCommon trees here are firs and pines, and

certainly redwoods on the US West Coast Pine barrens of New Jersey contain pitch pines

and scrub oaks

Arctic tundra: has harsh climate that recieves less than 25cm of rainfall per year mostly in the form of snowThis biome is located between the polar ice cap

and forests of Northern Hemisphere Contains permafrost that is permanently

frozen ground and rich reservoir of carbon

Supports lichens, wolves, voles, caribou

Alpine tundra: found in areas with very high altitudes Winds are strong here so plant life consists of

several species of low-lying plants