Chapter 7 - Climate and Terrestrial Biodiversity

Weather

Short-term properties of the troposphere at a given place and time

Climate

the average long-term weather of an area

Important factors in climate

average temperature and average precipitation of an area

1st factor of a climate factor

uneven heating of the earth’s surface (air is heated at the equator and cooled at the poles)

2nd factor of a climate factor

seasonal changes (the earth’s axis is tilted to create opposite seasons in the northern and southern hemispheres

3rd factor of a climate factor

Coriolis effect (deflection of winds to the right in the northern hemisphere and to the left in the southern hemisphere due to the rotation of the earth)

4th factor of a climate factor

long-term variations in the amount of solar energy striking the earth (due to orbital changes)

5th factor of a climate factor

properties of air and water (evaporation of heated water creates low pressure systems at the surface)

Greenhouse effect

natural trapping of heat in the troposphere

greenhouse gasses

allow light, infrared radiation and some ultraviolet radiation fro the sun to pass through the troposphere. The Earth’s surface absorbs this energy and radiates it back out as heat. The heat is then absorbed by the ______ or radiated back toward earth, heating the atmosphere.

composition of greenhouse gasses

water vapor, carbon dioxide, ozone, methane, nitrous oxide, and chlorofluorocarbons

El Nino-Southern Oscillation (ENSO)

a periodic climate change that can trigger extreme weather changes over two-thirds of the globe. The prevailing westerly winds weaken or cease in the Pacific Ocean which makes the surface water warmer along the North and South American coasts.

Biomes

terrestrial regions with characteristic types of natural, undisturbed ecological communities adapted to the climate of the region

desert

a biome where evaporation exceeds precipitation; precipitation is typically less than 25 cm per year

desert coverage

30% of the earth’s surface, mainly between 30 degrees north and 30 degrees south lattitude

Desert Plant Adaptations

include small or no leaves, wax-coated leave, tap roots, and spines

Desert Animal Adaptations

include nocturnal lifestyle, thick outer coverings, and dry/concentrated waste

Desert Habitat Destruction

particularly harmful because of slow plant growth, low species diversity, slow nutrient cycling and water shortage

Salinization

buildup of salt in soil due to evaporation of water for irrigation

Aquifer depletion

causes some deserts to subside (sink)

Desert extraction of natural resources

oil, iron ore, copper, gold, silver, diamonds, and sand

Grassland

Biome with enough average precipitation to allow grass to prosper, but with precipitation so erratic that drought and fire prevent large stands of tree from growing

Human impact of mining

drilling for oil, natural gas and other natural resources

Human impact of grazing

of domesticated animals on grasslands support 50 million people, mostly in Africa and Asia

Human impact of conversion of grassland

into cropland due to fertile soils

Tropical Grassland

found in areas with high average temperature, low to moderate precipitation, and prolonged dry season

savannas

tropical and subtropical grasslands that are warm all year with alternating wet and dry seasons

temperate grasslands

have large temperature differences from season to season and little rain that is unevenly distributed through the year

types of temperate grasslands

tall-grass prairies, short-grass prairies, pampas, veldt, and steppes

polar grasslands/arctic tundra/alpine tundra

very cold with the small amount of precipitation falling as snow

permafrost

perennially frozen layer of the soil

chaparral (temperate shrubland)

occurs along coastal areas where the winters are mild and moderately rainy and summers are long, hot, and dry

dominators of chaparral

dense growth of spiny evergreen shrubs

three main types of forests

tropical, temperate, and boreal

tropical rainforests

broadleaf evergreen forests with a warm annual mean temperature, high humidity, and heavy rainfall almost daily

tropical deciduous forests/tropical monsoon forests/tropical seasonal forests

warm year-round with most rainfall occurring during a monsoon season

layers of a tropical rainforest from top to bottom

emergent layer

canopy layer

understory layer

immature layer

herb layer

temperate rain forests/coastal coniferous forests

have moderate temperature with frequent rains

temperate deciduous forests

gave moderate temperatures that change significantly from season to season with abundant precipitation spread throughout the year

boreal forests/evergreen coniferous forests/taigas

have a dry and cold climate with long winters and short summers

logging of forests

dramatically decreases biodiversity of these areas (particularly tropical rain forests)

clear-cutting of forests

for use as cropland or grazing areas (particularly temperate deciduous forests)

hunting

of large predators

mining

of boreal forests for peat, iron ore, diamonds and other mineral

destruction

by air pollution and acid deposition

mountain regions

make up about 20% of the earth’s land surface and are important because of their dramatic changes in altitude, climate, soil and vegetation within short distances

mountains contain

majority of the world’s forests

100-meter gain in elevation

is equivalent to 100-meter kilometer change in latitude

extraction of

timber and mineral resources

growing number of

hydroelectric dams and reservoirs altering local ecosystems

recreational disturbances

skiing, trekking, tourism

increased air polution

primarily from automobile use

change in climate and UV radiation

due to global warming and ozone depletion

increased _____

warfare