ap environmental science terrestrial biodiversity andclimate © brooks/cole publishing company / itp

AP Environmental ScienceAP Environmental Science

Terrestrial Biodiversity Terrestrial Biodiversity

andand

ClimateClimate

© Brooks/Cole Publishing Company / ITP

1. Weather & Climate1. Weather & Climate


What is the difference between weather and climate?

• Weather- short–term properties of troposphere (temperature, pressure, humidity, precipitation, solar radiation, cloud cover, wind direction and speed)

• Troposphere- the lowermost atmospheric layer where weather occurs

• Climate- general, long–term weather of a region.

• Global temperature and precipitation patterns are determined by uneven heating of Earth by Sun and lead to distinct climate zones according to latitude.

Climate

the average weather patterns for an area overa long period of time (30 - 1,000,000 years).

is

It is determined by

Average Precipitation Average Temperatureand

which are influenced by

latitude altitude ocean currents

and affects

where people live how people livewhat they

grow and eat

© 2004 Brooks/Cole – Thomson Learning

Climate: Global PatternsClimate: Global Patterns


Major factors influencing climate:

• Air circulation patterns which are determined by

1. Uneven heating of Earth's surfaceuneven heating of troposphere from beneath.

2. Seasonal changes in temp and precipitation due to Earth's tilt on axis and revolution about the sun

3. Earth's rotation on its axis

4. Special properties of air, water, and land affect global air circulation (land absorbs heat faster than water but water releases the heat slower)

5. Wind Formation

• Ocean currents (water circulation)- Influenced by factors that influence air circulation plus

differences in water density.


Earth's tilted axis (23.5º) causes more direct sunlight at equator and more dispersed sunlight at higher latitudes.

This plays a major role in weather and climate. Fig. 7–3

Climate: Air Circulation PatternsClimate: Air Circulation PatternsUneven Heating of Earth’s SurfaceUneven Heating of Earth’s Surface

Air Circulation Patterns:Air Circulation Patterns:Rotation of Earth on AxisRotation of Earth on Axis

Earth’s surface turns faster under equator than at poles

This deflects the movements of winds moving N or S to the W at the equator and the E closer to the poles.

Air Circulation Patterns:Air Circulation Patterns:Special Properties of Air, Water Special Properties of Air, Water

and Landand Land


Fig. 7–5

Air circulation patterns, such as vertical convection currents, mix air in the troposphere and transport heat and water from one area to another in circular convection cells, called Hadley cells.

Global Air Circulation PatternsGlobal Air Circulation Patterns


Fig. 7–6

Conceptual model of global air circulation and biomes.

Greenhouse EffectGreenhouse Effect


The greenhouse effect- a natural process in which heat–trapping gases (CO2, H2O,

etc.) trap heat in the troposphere. Without the greenhouse effect, Earth would be cold and lifeless.

Fig. 7–9

Climate: Ocean CurrentsClimate: Ocean Currents


Major patterns:

• Ocean current kinetic energy (in form of heat) transferred from air circulation (winds) to water at ocean surface

solar energy –> wind kinetic energy –> ocean kinetic energy

• Deep currents driven by cooling and by increased salinity – both make water denser and cause to sink;

• Currents redistribute heat and moderate coastal climate

Example: Gulf stream brings warm water far north to cause NW Europe to be warm (otherwise Europe would have subarctic climate).

Weather & ClimateWeather & Climate


Fig. 7–2

Currents: UpwellingCurrents: Upwelling


Upwelling- a process that brings deep, cool, nutrient–rich waters up to replace surface water, leading to increased primary productivity, with large populations of phytoplankton, zooplankton, fish, and fish–eating birds.

Fig. 7–7

El Niño–Southern Oscillation (ENSO)El Niño–Southern Oscillation (ENSO)


ENSO- A periodic shift in global climate conditions (every 3–4 yrs)

Western flowing (called “easterly”) winds in the Pacific Ocean weaken or ceaseSurface water along N. and S. America become warmerUpwelling decreasesPrimary productivity along the S.A. coast declines sharply ***Strong ENSO affects over two–thirds of the globe.

Earth System: El Niño

El Niño–Southern Oscillation (ENSO)El Niño–Southern Oscillation (ENSO)


Fig. 7–8

El Niño

Unusually warm periods

Unusually high rainfall

Drought

MicroclimateMicroclimate


Topography, water bodies and other local features create local climate conditions different from the norm known as microclimate.

Mountains commonly result in high rainfall on the windward side and low rainfall in the rain shadow of the leeward side.

Urban areas with lots of brick, asphalt and concrete absorb sunlight and reradiate it as heat to the air.

Fig. 7–10

2. Biomes2. Biomes


Varying climates lead to varying communities of organisms.Biomes- the major types of terrestrial ecosystems

• **Determined primarily by climate (precipitation and temperature)

• Major groupings of biomes (desert, grassland, forest and mountain) found in tropical, temperate and arctic conditions.

• Similar traits of plants and animals for biomes of different parts of world; because of similar climate and evolutionary pressures (convergence)

• Types of plants in a biome

is dictated by precipitation

Biomes: Desert, Grassland, Biomes: Desert, Grassland, Forest and MountainForest and Mountain


Fig. 7–11

Earth's major biomes.

3. Desert Biomes3. Desert Biomes


Fig. 7–14

Climate graphs showing typical variation in annual temperature and precipitation for tropical, temperate and polar deserts.EVAPORATION EXCEEDS PRECIPITATION

DesertDesert BiomesBiomes


Characteristics:• Low precipitation--< 25 cm (10 in) annually

• Sparse, widely spaced, mostly low vegetation

• 30% of land surface, especially at 30° N and 30° S latitude

• Largest on interiors of continents;

• Plants typically deep rooted shrubs with small leaves, succulents, or short–lived species that flourish after rain

• Animals typically nocturnal and have physical adaptations for conserving water and dealing with heat

• FRAGILE BIOME DUE TO LONG REGENERATION TIME OF VEGETATION WHEN DESTROYED!

• American Field Guide Viewer-Deserts

Natural Capital Degradation

Deserts

Large desert cities

Soil destruction by off-road vehicles and urban development

Soil salinization from irrigation

Depletion of underground water supplies

Land disturbance and pollution from mineral extraction

Storage of toxic and radioactive wastes

Large arrays of solar cells and solar collectors used to produce electricity

4. Grassland, Tundra and Chaparral 4. Grassland, Tundra and Chaparral BiomesBiomes


Fig. 7–17

•Climate graphs showing typical variations in annual temperature and precipitation in tropical (savannas), temperate and polar grasslands (tundras)•THE ARCTIC TUNDRA IS THE MOST FRAGILE BIOME!!—bitter cold, slow rate of plant growth and decomposition, therefore shallow soil.

Grassland BiomesGrassland Biomes


Characteristics:• Sufficient rainfall to support grass, but

often too dry for forests

• Mostly on interiors of continents

• Maintained by seasonal drought, grazing and periodic fires that prevent invasion by shrubs and trees

• High diversity of grasses and herbaceous plants that typically have resistance to drought, grazing and fire

• **Fertile topsoil EXCEPT in arctic tundra

• Animals include large and small herbivores, along with predators adapted to feed on these herbivores.

Grassland Biomes: ChaparralGrassland Biomes: Chaparral

Characteristics: Found in many coastal

regions that border on deserts (i.e. California)

Temperate shrubland Consists of dense

growths of low-growing evergreen shrubs and small trees

Very susceptible to fires, but is also maintained by them


Grasslands

Conversion of savanna and temperate grasslands to cropland

Release of CO2 to atmosphere from burning and conversion of grassland to cropland

Overgrazing of tropical and temperate grasslands by livestock

Damage to fragile arctic tundra by oil production, air and water pollution, and off-road vehicles

5. Forest Biomes5. Forest Biomes


Fig. 7–22

Climate graphs showing typical variations in annual temperature and precipitation in tropical, temperate and polar forests (boreal, or taiga).

Forest BiomesForest Biomes


Characteristics:• Sufficient rainfall to support growth of

trees but soil nutrients are major limiting factor

• 3 types:- Tropical, typically broadleaf evergreen

trees with high diversity (2% of Earth’s surface but are habitats for at least 50% of our Earth’s terrestrial species)

- Temperate, typically deciduous broadleaf tree with moderate diversity and **nutrient rich soil

- Boreal (taiga), typical conifers (needle leaves) with low diversity. American Field Guide Viewer--Taiga

Forest BiomesForest Biomes

• Community of plants and animals typically distributed in various layers and various niches:

- Understory of herbaceous plants and shrubs

- Subcanopy of tree saplings

- Canopy of full grown trees.- Emergent layer gets most

direct sunlight


Forests

Clearing and degradation of tropical forests for agriculture, livestock grazing, and timber harvesting

Clearing of temperate deciduous forests in Europe, Asia, and North America for timber, agriculture, and urban development

Clearing of evergreen coniferous forests in North America, Finland, Sweden, Canada, Siberia, and Russia

Conversion of diverse forests to less biodiverse tree plantations

Damage to soils from off-road vehicles

MountainIce and snow

Altitude

Tundra (herbs,lichens, mosses)

ConiferousForest

Tropical Forest

DeciduousForest

Tropical Forest

DeciduousForest

ConiferousForest

Tundra (herbs,lichens, mosses)

Polar iceand snow

Latitude

6. Mountain Biomes6. Mountain Biomes •Similar changes in vegetation type occur when increasing latitude or increasing altitude•Each 100 m (300 ft) gain in elevation is approximately equal to a 100 km (62 mi) change in latitude

Mountain BiomesMountain Biomes


Characteristics:• Diversity of habitat because of altitude,

slope orientation, corresponding

microclimate and soil over short distances;

• Complex patterning of vegetation

• 20% of Earth's surface

• Majority of world's forests

• Timberline- elevation above which

trees do not grow

• Snowline- elevation above which

there is permanent snow

• Important as watersheds for lowlands.


Mountains

Landless poor migrating uphill to survive

Hydroelectric dams and reservoirs

Increasing tourism (such as hiking and skiing)

Air pollution from industrial and urban centers

Increased ultraviolet radi-ation from ozone depletion

Timber extraction

Mineral resource extraction

Soil damage from off-road vehicles

7. Perspectives on Geographical 7. Perspectives on Geographical EcologyEcology


• Important Lessons- Everything is connected

- Temperature and precipitation result patterns result from interplay of incoming solar radiation and geometry of Earth's rotation and orbit

- Temperature and precipitation are major determinants of the distribution of organisms

- Understanding the range of biodiversity and its distribution provides a global perspective.

- Teachers' Domain: Earth as a System

ap environmental science terrestrial biodiversity andclimate © brooks/cole publishing company / itp

Documents

air circulation winds

precipitation patterns

average weather patterns

special properties of

climate general

water denser

water density

earths rotation