Chapter 4: Ecosystems The Living World Unit. Members of an Ecosystem Eukaryotic cells (have nucleus) Prokaryotic cells (no nucleus/bacteria) Different.

Chapter 4: Ecosystems

The Living World Unit

Members of an Ecosystem

• Eukaryotic cells (have nucleus)

• Prokaryotic cells (no nucleus/bacteria)

• Different Species

• Within a specific range/distribution

• Direct or indirect interactions among populations

• ALL ecosystems make up Earth’s Biosphere

Biosphere 2 Project• 3.15 acre structure built in the 1980’s in Arizona

to see if a sealed, self-sustaining environment was possible. ($200 million; privately funded)– Unable to control temperature

• Contained:– Over 3,500 plant and animal species– 5 biomes: desert, grassland, marsh, ocean, rainforest– 8 humans (1991-1993)

• Outcome:– After 1 year, oxygen levels dropped too much and

had to be pumped in– 76% of vertebrate species went extinct– Ocean became too acidic– Air pollution– Is now owned by Columbia University

Vegetationand animals

Soil

Rock

Biosphere

Crust

Core

Mantle

Lithosphere(crust, top of upper mantle) Hydrosphere

(water)

Atmosphere(air)

Biosphere(Living and dead

organisms)

Crust(soil and rock)

“Spheres”

Oceanic crust Continental crust

Lithosphere

Upper mantle

Asthenosphere

Lower mantle

Biomes/Zones of Earth

• Terrestrial portions are called biomes– Forests (conifer, deciduous, rain forest)– Deserts– Grasslands

• Aquatic Life Zones– Freshwater (lakes, ponds, rivers, streams,

wetlands)– Marine (coral reefs,

coastal regions, deep ocean)

Solarradiation

Energy in = Energy out

Reflected byatmosphere (34%)

UV radiation

Absorbedby ozone

Absorbedby the earth

Visiblelight

Lower stratosphere(ozone layer)

Troposphere

Heat

Greenhouseeffect

Radiated byatmosphere

as heat (66%)

Earth

Heat radiatedby the earth

It starts with the sun!

1 billionth of sun’s output reaches Earth

Carbon dioxide, methane, NOx, H2O, O3: natural sources

Photosynthesis• Formula:

Carbon dioxide + water + sunlight glucose + oxygen

CO2 + H2O + solar Energy C6H12O6 + O2

• Producers or autotrophs are capable of photosynthesis

• Chemosynthesis: photosynthesis without sunlight (specialized bacteria can do this)

• Autotrophs/producers are typically found at the bottom of the “food chain”

Who are you calling a Heterotroph?• Scavengers

– Nutrients from dead and decaying animal/meat

• Omnivores– Nutrients from both plant and animal matter

• Carnivores– Nutrients from animals/meat

• Herbivore– Nutrients from plant material

• Detritivore– Nutrients from dead organic matter (plant or animal)– Decomposers put nutrients back into ground

MushroomWoodreduced

to powder

Long-hornedbeetle holes

Bark beetleengraving

Carpenterant

galleries

Termite andcarpenter

antwork

Dry rot fungus

Detritus feeders Decomposers

Time progression Powder broken down by decomposersinto plant nutrients in soil

Detritivores

Respiration is more than breathing?• Aerobic respiration: making energy in

the presence of oxygen

Glucose + oxygen carbon dioxide + water + energy

C6H12O6 + 6O2 6CO2 + H2O + energy

• Anaerobic respiration: energy gained in absence of oxygen. By products include methane gas, acetic acid

This process was taking place in waste water treatment plant!

Variety is the Spice of Life

• Genetic diversity: variety of genetic material/traits within a population.

• Species diversity: the number of species present in an area.

• Ecological diversity: variety of ecosystems found in an area or on the Earth

• Functional diversity: Biological and chemical processes needed for survival

Heat Heat Heat Heat

Heat

Heat

Heat

First TrophicLevel

Second TrophicLevel

Third TrophicLevel

Fourth TrophicLevel

Solarenergy

Producers(plants)

Primaryconsumers(herbivores)

Tertiaryconsumers

(top carnivores)

Secondaryconsumers(carnivores)

Detritivores(decomposers and detritus feeders)

Heat Heat

Types of Consumers

Ecological Efficiency

• Ecological efficiency: useable energy that is passed along from one trophic level to the next. Typical is 10% efficient (90% of energy is lost)

Top carnivores

Carnivores

Herbivores

Producers

5,060

Decomposers/detritivores

20,810

3,368

383

21

Heat Heat Heat Heat

Heat

Heat

Heat

First TrophicLevel

Second TrophicLevel

Third TrophicLevel

Fourth TrophicLevel

Solarenergy

Producers(plants)

Primaryconsumers(herbivores)

Tertiaryconsumers

(top carnivores)

Secondaryconsumers(carnivores)

Detritivores(decomposers and detritus feeders)

Heat Heat

Food Chains

Humans

Blue whale Sperm whale

Crabeater seal

Killerwhale Elephant

seal

Leopardseal

Adéliepenguins Petrel

Fish

Squid

Carnivorous plankton

Krill

Phytoplankton

Herbivorouszooplankton

Emperorpenguin

Food Webs

The dirt on dirt

• Soil horizon: a horizontal layer with a distinct texture and composition. (soil triangle)

• Soil profile: cross section of horizons. Can use a sampling tube to see profile. Mature, undisturbed soils have at least 3 of the 4 horizons.

Soil Profiles

• We will complete soil profile pictures by using text. Feel free to view these slides from the website at a later time to understand each of the horizons that make up the various profiles.

• Viewing them in lecture would be quite boring.

O horizon• Location: very top of ground to a few

inches down• Composition: undecomposed leaves,

partially decomposed leaves, twigs, grasses, crop waste, animal waste, fungi

• Color: brown or black• Additional information: not very deep;

some biomes have very little O horizon (desert)

A Horizon• Location: Just underneath O Horizon• Composition: has partially decomposed organic

matter (humus), inorganic nutrients. Also known as topsoil.

• Color: brown or dark brown (fertile), gray, yellow, reddish (not as fertile)

• Additional information: Depth will varying by biome/region. Lots of life (bugs, worms, bacteria, fungi)

• Bottom of A Horizon is the zone of Eluviation (or E horizon). Loss of minerals and nutrients here – were pushed downward.

E Horizon

• Location: Underneath A horizon (sometimes is included as just a part of the A horizon)

• Composition: Lacking in nutrients, leaching of nutrients into B horizon occurs here

• Color: lighter shade of the A horizon• Additional information: E horizon may

be included as a part of the A horizon and not listed. Mostly found in forested area soils.

B Horizon

• Location: Underneath E or A horizon

• Composition: More dense because of fine particles from upper zones leaching down. Also called subsoil

• Color: yellowish to brown

• Additional information: Typically a dense layer with more clay content. Depth of B horizon may vary by biome/region

• Cool animation of leaching.

C Horizon

• Location: Fairly deep – 3+ feet down

• Composition: Chunks of rock and parent material of the upper layer soil. Mostly inorganic

• Color: lighter – rock.

• Additional information: C horizon is also referred to as the Parent material and contains clay, sand, gravel.

R Horizon

• Location: Under the C horizon

• Composition: solid bedrock

• Color: lighter – rock.

• Additional information: R horizon is not considered soil. It is solid bedrock. May not be shown on all graphics/profiles.

ProfilesO Horizon

A Horizon

E Horizon

B Horizon

C Horizon

Weak humus-mineral mixture

Mosaicof closelypackedpebbles,boulders

Dry, brown toreddish-brown, with variable accumulationsof clay, calciumcarbonate, andsoluble salts

Desert Soil(hot, dry climate)

Grassland Soil(semiarid climate)

Alkaline,dark, and richin humus

Clay, calciumcompounds

Soil Profiles - Biomes

A

B

C

O

A

E

B

C

R

Tropical Rain Forest Soil(humid, tropical climate)

Deciduous Forest Soil(humid, mild climate)

Coniferous Forest Soil(humid, cold climate)

Soil Profiles - Biomes

OA

E

BC

R

OAE

B

C

R

O

B

C

R

A/E

Soil Texture PyramidFind:

50% clay

15% sand

35% silt

Soil Texture Pyramid 2Find:

30% clay

35% sand

35% silt

Figure 4-28Page 76

Precipitation Transpirationfrom plants

RunoffSurface runoff

Evaporationfrom land Evaporation

from oceanPrecipitation

Ocean

Surfacerunoff

Groundwater movement

Condensation

Infiltration andPercolation

Water Cycle

Diffusion

Carbon dioxidedissolved in ocean water

Marine food webs

Marine sediments, includingformations with fossil fuels

Combustion of fossil fuels

sediments death, sedimentation

uplifting over geologic time

sedimentation

photosynthesis aerobic respiration

Carbon Cycle

photosynthesis aerobic respirationTerrestrial

rocks

Soil water(dissolved

carbon)

Land food webs

Atmosphere

Peat,fossil fuels

combustion of wood

sedimentation

volcanic action

death, burial, compaction over geologic timeleaching

runoff

weathering

Carbon Cycle

Combustion of fossil

fuels

NO3 –

in soil

Nitrogen Fixation

(Legumes)

Fertilizers

Food Webs On Land

NH3, NH4+

in soil

1. Nitrification

bacteria convert NH4+ to

nitrate (NO2–)

loss by leaching

uptake by autotrophs

excretion, death,

decomposition

uptake by autotrophs

Nitrogen Fixationbacteria convert N2 to

ammonia (NH3) ; this

dissolves to form ammonium

(NH4+)

loss by leaching

Ammonificationbacteria, fungi convert the

residues to NH3 , this

dissolves to form NH4+

2. Nitrification

bacteria convert NO2- to

nitrate (NO3-)

Denitrificationby bacteria

Nitrogenous Wastes, Remains In Soil

Gaseous Nitrogen (N2)

in Atmosphere

NO2 –

in soil

Nitrogen Cycle

© 2004 Brooks/Cole – Thomson Learning

Nitrogen

• Ways nitrogen gets INTO ground

• Ways nitrogen leaves ground:

LighteningDecompositionNitrification (legumes)Fertilizer

LeachingDenitrificationUse by autotrophsHarvesting/removal of crops

GUANO

FERTILIZER

ROCKS

LAND FOOD WEBS

DISSOLVED IN OCEAN

WATER

MARINE FOOD WEBS

MARINE SEDIMENTS

weathering

agriculture

uptake by autotrophs

death, decomposition

sedimentation settling out weathering

leaching, runoff DISSOLVED IN SOIL WATER,

LAKES, RIVERS

uptake by autotrophs

death, decomposition

miningmining

excretionexcretion

Phosphorous Cycle

uplifting over geologic time

Phosphorous

• Ways phosphorous gets INTO ground

• Ways phosphorous leaves ground:

GuanoPhosphate saltsFertilizerDecompositionsweathering

Uptake by autotrophsUse in food chains and websSedimentation/rock cycle

Sulfur Cycle

Sulfur

Hydrogen sulfide

Sulfate salts

Plants

Acidic fog and precipitation

Ammonium sulfate

Animals

Death, decayMetallicsulfide

deposits

Ocean

Dimethyl sulfide

Sulfur dioxide Hydrogen sulfide

Sulfur trioxide Sulfuric acidWater

Ammonia

Oxygen

Volcano

Industries

Sulfur

• Ways sulfur gets INTO ground/atmosphere

• Ways phosphorous leaves ground:

FertilizerVolcanoesHot springsFactory emissions

Uptake by autotrophsUse in food chains and websSedimentation/rock cycle