Ecology and the BiosphereEcology and the Biosphere

Chapter 52

Earth from the moonEarth from the moon

Ecology Ecology

Ecology is the study of Distribution and Abundance of organisms over time.

Distribution is where we naturally find / found an organism

Abundance is how many individuals are / were counted at the study sites

Fig. 52-2Fig. 52-2

Organismalecology

Populationecology

Communityecology

Ecosystemecology

Landscapeecology

Globalecology

Ecological levelsEcological levels Populations include all the members of one

species in a given area and time. Species include all of the potentially interbreeding

populations. Community includes all of the different species

(plants, animals, fungi, etc.) living in the area Ecosystem includes the Biotic and Physical

components of the environment Landscape- Interactions between connected

ecosystems Biosphere is world –wide issues, like Global

warming, and pollution

ClimateClimate

Determines what plants can grow thereTwo major factors of climate:

– Temperature (warm to cold)– Precipitation (moisture – wet to dry)

Position on globe determines climate

TemperatureTemperature

Simple gradient from warm to cold by increasing latitude

Solar intensity greatest and warmer at equator (0o)

Less intense and cooler at poles (90o).

Solar radiationSolar radiation

Solar radiation around the Globe

Solar radiation around the Globe

PrecipitationPrecipitation

Alternating bands of wet and dry areas along a latitudinal gradient

Wet at equator 00, and 600 N / SDry at 300, and 900 poles

– Poles are frozen desertsCaused by formation of Hadley Cells

Hadley CellsHadley Cells

Air rises (00, 600) due to warming of surface.

– as the air rises it becomes less dense and cooler, dropping water as rain.

Air falls (300, 900 poles) – air becomes compressed, and heats. It

absorbs moisture and falls as dry air.

Global air circulation, precipitation, and winds: Hadley cellsGlobal air circulation, precipitation, and winds: Hadley cells

Convection CurrentsConvection Currents

Global air circulation is affected by the properties of air water, and land.

Figure 5-5Figure 5-5

Global Air CirculationGlobal Air Circulation

Hadley cell

West Coast LatitudesWest Coast Latitudes

Dry : nearer 300

– San Diego=32.5; LA= 34; Sta. Barbara= 34.5

– Santa Cruz =37, SF 37.75; – Eureka= 40.75

Wetter nearing 600:

– Portland= 45.5; Seattle= 47.5 – Juneau= 58; Anchorage = 61

Hadley - Ferrel cellsHadley - Ferrel cells

Coriolis EffectCoriolis EffectGlobal air

circulation is affected by the rotation of the earth on its axis.

Figure 5-4Figure 5-4

Prevailing windsPrevailing winds

These Hadley cell wind currents move North or South

The spinning of the earth makes it seem like they come at an angle.– In CA our winds, storms usually come from

the south west.– Our Rains often bring warmer weather

Global Trade Wind PatternsGlobal Trade Wind Patterns

Ocean currentsOcean currents Prevailing winds cause ocean waters to

move in the prevailing direction. Northern Pacific flows clockwise

– Sea level 4 feet higher in Asia Water flows from Alaska southwards along

our coast Near shore upwelling brings cold, nutrient

rich water up along our shore – Very high productivity of tidal areas

Ocean CurrentsOcean Currents

Wind from the north starts surface ocean water moving

Earth's rotational force deflects moving water westward

c. Deep, cold watermoves up to replacewater moving west

Upwelling

SeasonsSeasons

Caused by tilting of earth on its rotational axis.– Intensity of sunlight varies.– Most extreme at poles– Little change at equator.

Seasons- Seasons-

Tilting of earth moves solar equator. Effectively moves solar 300 dry zone

north in summer The wet belt moves farther south

giving us wet winters

Causes of SeasonsCauses of Seasons

BiomesBiomes

Major vegetation types that also determine the animal community present.

Determined mostly by climate – Soil also important factor

Common California Biomes Common California Biomes Dry to WetDry to Wet

Desert - driestChaparral – shrubs with fire cycleGrasslands – no trees, all grassSavanna – widely spaced trees in grassWoodland – open canopyForest – closed canopy, wettest

A climograph for some major kinds of ecosystems (biomes) in North AmericaA climograph for some major kinds of ecosystems (biomes) in North America

BiomesBiomes

Major BiomesMajor Biomes

Patterns of distribution in the biospherePatterns of distribution in the biosphere

Coniferous forest, Lady Bird Grove (top left), Sequoias (right), rain Coniferous forest, Lady Bird Grove (top left), Sequoias (right), rain forest (bottom left)forest (bottom left)

Temperate deciduous forest, Great Smokey Mountains National ParkTemperate deciduous forest, Great Smokey Mountains National Park

Tropical forestsTropical forests

SavannaSavanna

Desert. Organ Pipe State Park (top), Joshua Tree National Park (bottom left), Desert. Organ Pipe State Park (top), Joshua Tree National Park (bottom left), Death Valley (bottom right)Death Valley (bottom right)

Temperate grassland- PrairieTemperate grassland- Prairie

Tundra. Denali National Park (left), reindeer (right)Tundra. Denali National Park (left), reindeer (right)

Rain shadow Rain shadow Precipitation increases as storms are

pushed up over mountains.– accordingly rain becomes snow

– As air moves up slope in the Sierras it cools 3-5 degrees per 1,000 ft.

This is the same effect as moving 300 miles farther north !

Causes deserts in Nevada

Most islands with mountains have wet and dry sides

RainshadowRainshadow

RainshadowRainshadow

Biotic Zonation of SierrasBiotic Zonation of Sierras

Summer FogSummer Fog

Summer Fog Summer Fog

– Inland air warms quickly. This rising air, pulls in coastal air.

– Marine air is pulled inland by this draw in the Central valley – causing summer winds over the low passes (Altamont)

– Cold water off CA. coast cools incoming warm, moist ocean air- causing condensation.

Essential for ranges of Coast Redwoods, relic pines and cypress species .

Can add up to 10 inches of summer precipitation in some areas.

FOG HEAVEN / The sun will come out tomorrow. Or maybe not. It's summer in the city, and that means gray skies.

What causes fog. Chronicle Graphic

Central Valley SmogCentral Valley Smog

: weblog.rudayday.com/archives/2005_08.html

Smog moves up into SierrasSmog moves up into Sierras

Temperature Inversion layersTemperature Inversion layers

dense air flows downhill and collects in low spots, valleys. Great Central valley is an example.

– This dense air may be blocked by hills etc. from warmer winds which blow over the top of dense air, leaving it alone.

– Dense tule fog may form for days. Inversion layer (cold air higher up) also traps

pollutants. Mexico City problems Reno, Tahoe now ban fireplaces.

Often “burn off” in summer but leave the haze of phytochemical smog behind.

Ocean ZonesOcean Zones

Intertidal – species rich zone on rocks between high and low tides levels.

Photic – upper sunlit layers where phytoplankton (producers) live

Neritic – productive zone over Continental Shelf

Oceanic - Open Ocean, nutrient poor low productivity