Topic 1: What is Ecology?

• Defined: Studying how life interacts within the biosphere is called Ecology

• All life interacts within the biosphere– Area within the deepest ocean trenches to the

highest mountains

• Defined: Group of one species living in the same area• Population changes based on:

– Births, Deaths, Immigration, Emigration, Available resources

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Populations

Limiting Factors• Defined: Factors

that control population sizes– Disease, food,

predators, climate, space, mates

• Carrying Capacity: greatest number of individuals that a population can sustain

• What stage is the human population in?

Communities

• Defined: Populations of many species living in the same area at the same time

• Each organism has it own HABITAT– Habitat: Place where an organism lives

• Each species has its own NICHE– Niche: The role/needs of a species– Ex: Termites return nutrients to the soil

Ecosystems

• Defined: Community of species interacting with the living & non-living

• Desert Biotic Factors:– Animals: Mice, Reptiles, Insects– Plants: Cactus, Flowers, Shrubs

• Desert Abiotic Factors: Sand, rocks, sunlight• Ecosystem changes affect biodiversity

– Keystone species greatly alter ecosystems

What is a Biome?• Defined:

Large area with distinct climate, plant, and animal life

• Climate factors: sun, rain, topography

• Climate determines life

Part 2: Ecosystem Components• Producers

– Basis of an ecosystem’s energy

– Autotrophs: perform photosynthesis to make sugars

– Chemotrophs: Bacteria which use minerals from deep-sea vents to make energy

• Consumers– Heterotrophs: Consumes

others for energy– Omnivores, herbivores,

carnivores, decomposers

• Defined: Feeding level of an ecosystem

• Trophic levels consist of producers, consumers, and decomposers

• ~10% of energy is passed to the next level– Few trophic levels45,897 kcal

4589.7 kcal

458.97 kcal

45.897 kcal

4.5897 kcal

• Defined: Organisms that create their energy through photosynthesis–AKA: Autotrophs–Convert sunlight into

glucose (sugar)• Bottom of food chain

(1st trophic level)• Ex: Plants, Algae,

Cyanobacteria

• Primary Consumers– Feed directly on

producers– Herbivores

• Secondary Consumers– Feed on primary

consumers– Carnivores & omnivores

• Tertiary Consumers– Feed on secondary

consumers– Carnivores & omnivores

• Quaternary Consumers– Feed on tertiary

consumers– Carnivores & omnivores

• Decomposers: break down dead matter into simpler substances

• Returns nutrients to the soil

• Feed on any trophic level

Name the tropic levels in this food pyramid

• Defined: Group of interrelated food chains

• Arrows show direction energy (nutrients) travel

producer

Primary consumer

Secondary consumer

Tertiary consumer

producer

Primary consumer

Secondary consumer

Tertiary consumer

Quaternary consumer

Topic 3: Succession

Primary Succession

• Defined: Establishment and development of an ecosystem in an uninhabited environment

• Volcanic lava creates new land• Glaciers retreating exposing new land

Bare Rock

• Lava cools and hardens into rock

Pioneer Species

• Defined: First organisms to inhabit new land• Moss and lichen grow on bare rock• Dead matter accumulates with rock pieces

– Thin soil layer begins to accumulate

The Process Continues

• Seeds enter the area and grow• Small flowers & shrubs accumulate more

organic matter• With new plants, small animals inhabit the

area

The Process Continues

• Small trees take root in the accumulated organic matter

• More animals use the trees as a habitat

Climax Community

• Large trees take root– Overcrowd and out-compete original trees

• New animals inhabit new forests

Secondary Succession

• Changes that take place after a disturbance occurs in an established ecosystem– Forest fires, floods, tree falls…

• Faster scale (soil preexists)

Topic 4: Biogeochemical Cycles

Oxygen Cycle

• Autotrophs: Release O2 into atmosphere via photosynthesis• All life: Absorbs O2 to be used during cellular respiration

– Respiration: creates ATP energy for cells

O2

O2

Carbon Cycle

• Carbon = (organic molecules) carbohydrates, proteins, lipids, nucleic acids

• Plants & autotrophs:– Intake: Absorb CO2 from atmosphere– Output: Create carbohydrates by photosynthesis

CO2

CO2

sugars

Carbon Cycle

• Consumers– Intake: Carbon moves up the food chain as 1 feeds on another– Output: Release CO2 during respiration

CO2

CO2

sugars

Carbon Cycle

• Decomposers– Input: Feed on dead organic matter– Output: Release CO2 during respiration– Output: Organic molecules returned to soil during decomposition

C C

C

sugars

Carbon Cycle

• Human Industry– Output: Release CO2 into atmosphere when fossil fuels

(coal, oil, natural gas) are burned

CO2

Nitrogen Cycle

• N = 78% atmosphere (most unusable)• Soil Bacteria

– Nitrogen fixation: convert atmospheric nitrogen into ammonia– Nitrification: ammonia converted into nitrates

N2

Ammonia Nitrates

Nitrogen Cycle

• Plants– Absorb nitrates through their roots

Nitrates

Nitrogen Cycle

• Animals– Ingest nitrates through the food chain (plants eaten)

Nitrates

Nitrogen Cycle

• Decomposers– Feed on dead organisms– Return ammonia to soil by feeding on dead matter

Ammonia

Ammonia

Ammonia

NitratesNitrates

Phosphorus (P) Cycle• No

phosphorus in atmosphere

• Rocks– Phosphorus

released by weathering of rocksPP

Phosphorus (P) Cycle

• Plants– Absorb P

into their roots

P

Phosphorus (P) Cycle

• Animals– Ingest P

when plants eaten

– P continues to move up food chain

P

Phosphorus (P) Cycle• Decomposers

– Breakdown dead matter and release P into soil

PP

Phosphorus (P) Cycle

• Human Contribution– Adding

excess P from fertilizers

– P washes into lakes, etc…

– Excess P causes extreme algae growth

PP

P P

PP

Topic 5: Community Interactions• when organisms live together in an ecological

community they interact constantly.

• Three types of interactions– Competition– Predation– Symbiosis

Competition• occurs due to limited

resources– water, nutrients, light,

food.

• Competitive exclusion principle - no two species can occupy the same niche in the same habitat at the same time

Competition

Predation• Predation- when an

organism captures and feeds on another organism.

• Predator- hunter• Prey- hunted

Symbiosis• Symbiosis- any relationship where two

species live closely together. (3 types)– Mutualism– Commensalism– Parasitism

Symbiosis• Mutualism - both

species benefit from a relationship– Flower: gets pollinated– Moth: gets nectar

Mutualism example:Cleaner birds and Crocodiles

Symbiosis• Commensalism – One

member of a symbiotic relationship benefits and the other is neither helped or harmed– Anemone: gains nothing– Fish: protection

Symbiosis• Parasitism- One

creature benefits and one creature is harmed– Insect larvae will feed on

the caterpillar

Topic 6: Environmental Issues

Ozone Layer Depletion• Ozone Function:

Block UV radiation from sun

• Problems:– CFCs thinning the

ozone layer– More UV radiation

reaches the surface• Effects: Crop damage,

skin cancers, Eye damage

• Solution: Reduce CFCs, regrow trees

UV

Ozone layerOzone layer

CFCs

UV

The Greenhouse Effect• G.H.E. is naturally good

(it warms Earth)• Problem: Excess heat

trapped near the earth’s surface

• Fear: Climate patterns change, ice caps melt

• Main Cause: CO2 from burning of fossil fuels (coal, oil, natural gas)

• Solutions: Reduce use of fossil fuels, regrow trees, alternative energy sources

What’s in a name?

The purpose of a greenhouse is to trap heat year round

Earth

heat

heat

heat

Some heat escapes into space

Some heat naturally trapped by Earth’s atmosphere

Earth

EarthExcess CO2 in atmosphere

Less heat escapes into space

More heat trapped near Earth’s surface

The Greenhouse Effect is naturally GOOD!

Mars: No Greenhouse Effect

Little heat is trapped by the thin CO2 atmosphere. High temperatures can be around 20⁰F.

Earth: Balanced Greenhouse Effect

Average global temperature is 57⁰F.

Venus: The Extreme Greenhouse Effect

Heat is trapped by the thick CO2 atmosphere. Temperatures reach 750⁰F.

Deforestation• Defined: Clearing of

forested areas• Reasons:

– High demand for wood products

– Create farmland

• Problems:– Species lost– Excess CO2 released

• Solutions:– Recycle– Improved farming

techniques

The Smog and Ground-Level Ozone• Reason:

– Burning of fossil fuels & industry

• Problems:– Respiratory illness– Ozone gas is poisonous

• Causes:– Particulates rise into air

and react with sunlight to make air pollution

• Solutions:– Reduce use of fossil fuels– alternative energy sources– Plant trees

Non-native Species Introduction• Defined: Foreign organisms

are introduced to a new habitat• Reason:

– Pet industry, “free ride” organisms, pest control

• Effects:– Foreign species outcompete

native species– Food webs unbalanced– Economic damage

• Solutions:– Laws preventing foreign

goods into new countries– Introduce predators

Zebra mussels

Kudzu vines

• Defined: Precipitation with a below normal pH

• Cause:– Fossil fuel pollution rises

into the air & then falls as rain

• Effect:– Waterways more acidic– Kills plant and animal life

• Solutions:– Reduce fossil fuel usage– Add buffer (base) to

waterways

The Big Problem: Overpopulation• Over 6.7 billion people• Many natural resources

are nonrenewable– Fossil fuels take

millions of years to form• More people means:

– 1) More forests removed

– 2) More resources consumed

– 3) More CO2 released