Biology 205Biology 205Ecology and AdaptationEcology and Adaptation

Exam 1: Exam 1: ReviewReview

Fall 2015Fall 2015Dr. Erik D. DavenportDr. Erik D. Davenport

Ecology is…Ecology is…

the study of the study of interactionsinteractions among among living living thingsthings and their and their environmentsenvironments

… interactions between organisms and between organisms and their environment.… the distribution and abundance of organisms in the natural world.…how interactions between organisms and their environment shape the natural world.

Ecology is the study of…Ecology is the study of…

…the study of how to save the environment

but ecological concepts can be applied to environmental issues.

…a set of values, a political agenda, or a belief system

but your understanding of ecological concepts may affect your values.

Ecology is not…

Why is ecology required?

Sub-discipline of Biology Expose you to ecological and environmental

knowledge so that you can understand (or critically think about) some important environmental issues.

Levels of biological organizationLevels of biological organization

MoleculesMoleculesCellsCellsTissuesTissuesOrgansOrgansSystemsSystemsIndividualsIndividualsPopulationsPopulationsCommunitiesCommunitiesEcosystemsEcosystems

the scope of ecology

BiomesBiomes

– The areas on the earth that are distinguished primarily The areas on the earth that are distinguished primarily by their predominated plant and are associated with by their predominated plant and are associated with particular climates.particular climates.

– Such as Such as tropical rain forest biometropical rain forest biome, or , or desert biomedesert biome..

Why are there many different biomes on the Why are there many different biomes on the Earth?Earth?

--- Climate (environmental conditions) on the --- Climate (environmental conditions) on the Earth is not the same everywhere.Earth is not the same everywhere.

Each biome --- specific climateEach biome --- specific climate

Climate factors on LandClimate factors on Land

TemperatureTemperature

Rainfall (water)Rainfall (water)

SeasonSeason

Sun!!!!! – energy sourceSun!!!!! – energy source

Solar radiation is the sole energy source for Solar radiation is the sole energy source for all the organisms on the earth.all the organisms on the earth.

However, the radiation from sun is not However, the radiation from sun is not equally distributed on the earth. Why?equally distributed on the earth. Why?

Spherical shape of The earthSpherical shape of The earth

--- spherical shape of the earth causes --Different area on the Earth receives different amount of solar energy--- uneven heating –

-- temperature difference

Temperature, AtmosphericTemperature, Atmospheric Circulation, and Precipitation Circulation, and Precipitation

Temperature then drives air circulation Temperature then drives air circulation patterns and consequently precipitation patterns and consequently precipitation patterns.patterns.– Warm, moist air rises, Cools, condenses, and falls Warm, moist air rises, Cools, condenses, and falls

as rain.as rain.– Cooler, dry air falls back to surface.Cooler, dry air falls back to surface.

Rainforests found near equator.Rainforests found near equator. Major deserts found near 30Major deserts found near 30oo N / S. N / S.

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Solar-driven, latitude and atmospheric circulationFigure 2.5

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Why tilted axis is also important?-- seasons!!!

Earth tilted rotation axis

Earth rotation plainAround the sun.

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Seasons in Northern and Southern hemispheres

What factors contribute to the variation in What factors contribute to the variation in climate on the earth?climate on the earth?

Uneven heating of the earthUneven heating of the earth’’s spherical s spherical surface by the sunsurface by the sun and and the tilt of the earth on the tilt of the earth on its axisits axis combine to produce the predictive combine to produce the predictive latitudinal variation in climate.latitudinal variation in climate.

The geographic distribution of terrestrial The geographic distribution of terrestrial biomes corresponds closely to variation in biomes corresponds closely to variation in climate, especially the prevailing temperature climate, especially the prevailing temperature and precipitation.and precipitation.

Tropical Rain forest Tropical Rain forest

Tropical dry forestTropical dry forest

Tropical SavannaTropical Savanna

Temperate Woodland and shrublandTemperate Woodland and shrubland

Temperate GrasslandTemperate Grassland

Temperate Forest (Old Growth)Temperate Forest (Old Growth)

Boreal Forest (Taiga)Boreal Forest (Taiga)

TundraTundra

Water on EarthWater on Earth

-Water covers 71% of the earth.-Water covers 71% of the earth.– The ocean contains over 97% The ocean contains over 97%

of total water.of total water.– The polar ice caps and The polar ice caps and

glaciers contain additional 2%.glaciers contain additional 2%.– Only 1% of the water is Only 1% of the water is

freshwater that is in lakes, freshwater that is in lakes, rivers, and actively rivers, and actively exchanged groundwater.exchanged groundwater.

““Distribution of water is not static.Distribution of water is not static.””

– HeatHeat– EvaporationEvaporation– CloudsClouds– PrecipitationPrecipitation

EvaporationEvaporation Consumed by Consumed by

organismsorganisms GroundwaterGroundwater Surface waterSurface water

LargestLargestOcean Basins:Ocean Basins:

PacificPacific : ~180 million km : ~180 million km22

AtlanticAtlantic: ~: ~106 million km106 million km22

IndianIndian: ~75 million km: ~75 million km22

Ocean Structure:Ocean Structure:

Oceanic ZoneOceanic Zone::– EpipelagicEpipelagic 0 - 200 m0 - 200 m– MesopelagicMesopelagic 200 - 1,000 m 200 - 1,000 m– BathypelagicBathypelagic 1,000 - 4,000 m 1,000 - 4,000 m– AbyssalAbyssal 4,000 - 6,000 m 4,000 - 6,000 m– HadalHadal 6,000 6,000 ++ m m

BenthicBenthic: Habitat on bottom.: Habitat on bottom. PelagicPelagic: Habitat off the bottom.: Habitat off the bottom.

Light Penetration in the Light Penetration in the OceanOcean – Approximately 80% of Approximately 80% of

solar energy striking solar energy striking the ocean is absorbed the ocean is absorbed in first 10 m.in first 10 m.

– Very little, if any Very little, if any penetrates past 600 m.penetrates past 600 m.

– Leaves approximately Leaves approximately 3,400 m of deep black 3,400 m of deep black water with only light water with only light produced by produced by bioluminescence.bioluminescence.

Temperature in the OceanTemperature in the Ocean – Warm water will Warm water will decreases density, thus decreases density, thus warm water floats on warm water floats on top of cooler water.top of cooler water.

– Ocean water Ocean water temperature is more temperature is more stable than terrestrial stable than terrestrial temperature.temperature.

– ThermoclineThermocline: a layer of : a layer of water where water where temperature changes temperature changes rapidly with depth rapidly with depth (usually above 200m).(usually above 200m).

Creates thermal Creates thermal stratification.stratification.

Salinity

Estuaries, Salt Estuaries, Salt marshes and marshes and mangrove forestsmangrove forests

Salt marshes and mangrove forests are the Salt marshes and mangrove forests are the transition between land and seatransition between land and sea,, however, however, salt marshes are distributed mainly along salt marshes are distributed mainly along the sandy shores from temperate to high the sandy shores from temperate to high latitude, and mangrove forests are in latitude, and mangrove forests are in subtropical and tropical shores.subtropical and tropical shores.

What is What is estuarineestuarine? ? The The area where area where rivers meet the rivers meet the sea.sea.

Salt marsh

Mangrove

Estuary

Rivers and StreamsRivers and Streams

Riparian zoneRiparian zone is a is a transition area between transition area between the aquatic and upland the aquatic and upland terrestrial environments.terrestrial environments.

Salinity may fluctuate widely, particularly where Salinity may fluctuate widely, particularly where the tidal and river flow are substantial.the tidal and river flow are substantial.

DiurnalDiurnal tides: Single low tides: Single low and high tide each day.and high tide each day.

““Most important water Most important water movements affecting distribution movements affecting distribution

and abundance of intertidal and abundance of intertidal organisms are organisms are waves and tideswaves and tides..””

SemidiurnalSemidiurnal tides: Two tides: Two periods of low and high tides periods of low and high tides daily.daily.

Lake StructureLake Structure

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Oligotrophic and eutrophic lakesFigure 3.39

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