5 Levels of Ecological Organization

Species- organisms that can interbreed and produce fertile offspring

Population- all the members of 1 species in an area

Community- every species in an areaEcosystem- many communities and

their environmentBiosphere- the entire region of Earth

where living things can be found (many ecosystems)

What is Ecology?

Ecology- study of the interaction between organisms and their environment

Within an ecosystem there are two main componentsHabitat- place where organism livesCommunity- ALL the species in habitat

Biomes

Biomes are groups of terrestrial ecosystems that have the same climate and dominant communities

3 types of biomes: Temperate: seasonal Tropical: by equator and hot year round Arctic: far from equator and cold year

roundYou have forests, deserts and grasslands in

these different areas

Biomes

Aquatic LifezonesAquatic lifezones are aquatic ecosystems.Freshwater or saltwaterFreshwater

Wetlands are very important ecosystems Bogs, swamps or marshes Rivers Ponds Estuaries (wetlands where river meets

sea) Mangrove swamps

Saltwater (Marine) Coral Reefs Intertidal zone Open ocean

Biomes-22min

Species Interaction Many interactions take

place between species in a community

i.e.) predator and prey

Each organism plays a certain role in the community

Niche- role of an organism in which it interacts with other species and its environment (i.e. its job)

Abiotic vs. Biotic Factors

Abiotic- “non-living” components-ex) temperature, light, water, nutrients, boats

Biotic- “living” species -ex) sea turtle, sea grass, coral, fish, humans

Biotic Factors

Two categories of life based on how they get energy

All life is either a Producer OR Consumer

Biotic FactorsProducers- organisms that are capable of

producing their own energy source Photosynthetic (plants that take light to make

carbs) Chemosynthetic (some bacteria that can take

chemicals to make their carbs) All producers are autotrophs or “self-feeders”

KNOW THIS EQUATION!

Biotic FactorsConsumers- organisms

that can’t produce their own energy source, but have to consume it from another source

All consumers are heterotrophs or “other feeders

Many different types of consumers (heterotrophs)

-Herbivores-Carnivores-Omnivores-Decomposers

Look at each of the pictures and write in thespace below it whether it is a

producer or a consumer

Conditions for LifeFor an ecosystem to sustain life,

it must have: 1) Constant source of energy (sun).

2) Living system that converts sun’s energy into organic molecules. Plants!

3) Cycling of nutrients between organisms and environment (water, carbon dioxide, nitrogen, oxygen).

4) Decomposers- bacteria and other small organisms that breakdown and return unused nutrients to the environment.

Biodiversity

Biodiversity- The number of different species in an ecosystem

More plants = more animals

More biodiversity = healthier ecosystem

What Determines Biodiversity of

Ecosystem?SizeLatitude – Closer to

equator = more diverse.a) More sunlight and longer growing seasonb) More producers (plants)Why do we call plants producers?c) More producers = more consumers

Precipitation (i.e. rainfall)

Nutritional Interactions

All ecosystems must have interactions between producers, consumers, and decomposers

These interactions transfer nutrients and energy throughout the ecosystem

Energy flow in an ecosystem

Energy flows through an ecosystem from the sun to producers to consumers

***Arrows show the direction the energy flows

“Who Eats Who”… Food chain- straight

line sequence shows simple feeding relationships

Notice the direction of the arrows!

Sun

Producers

Primary consumers

Secondary Consumers

Tertiary Consumers

FLOWERProducer

CATERPILLARPrimary consumer

FROGSecondary consumer

SNAKETeriary consumer

OWLQuaternary consumer

Food web- illustrates how many food chains in an ecosystem are related

Primary consumers?Secondary

consumers?Tertiary consumers?Where would

decomposers fit in this food web?

How many trophic levels are possible?

Energy pyramids- show amount of energy at each trophic level

These are not food pyramids!!Trophic levels -levels of feeding from

producers (plants) to the consumers Few ecosystems have more than 4 or 5

trophic levels Energy diminishes at each level because it

is used for life’s processes

Pyramid of Energy

Which level has the most energy AVAILABLE?

Trophic levels Producers have

the most energy available

Primary consumers are all herbivores

Secondary consumers are small carnivores

Tertiary consumers are large carnivores

Part of the original energy from the sun is used at every level by the organisms for survival

How do organisms obtain nutrients?

Although energy moves through ecosystems in a one-way direction, nutrients are recycled

Three basic nutrient cycles are present in all ecosystems allowing organisms to obtain needed nutrients to function effectively

Nitrogen CycleThe atmosphere contains 80% nitrogen gas (N2) However, this nitrogen can not be used by most living thingsBacteria are the only organisms that use nitrogen gas directly from the atmosphereThey can fix nitrogen for plants to use by converting it into ammonia

DNA and proteins

N2

Nitrogen Cycle Processes

NH3

N2 YUMMY!

Nitrogen fixation- nitrogen gas in atmosphere converted to ammonia, NH3

(bacteria in soil, lightning)Nitrification- bacteria converting ammonia to nitrate (another form of nitrogen)Assimilation- absorption of ammonia and nitrate by plants

Nitrogen fixation

Assimilation

Nitrification

Nitrate

Nitrogen Cycle Processes

Ammonification- decomposers (bacteria and fungi) break down of dead organisms and waste and return nitrogen to soil as ammonia

Denitrification- conversion of ammonia back to nitrogen gas (decomposers)

Ammonification

NH3

N2

Denitrification

Nitrogen Cycle

Review Nitrogen Importance

Why is nitrogen important to living things?

How do plants obtain nitrogen?Why are bacteria SO important to the

nitrogen cycle?How do we obtain nitrogen?Nitrogen cycle movie with QUIZ

Water Cycle

Driving force is the sun and gravityConsists of the alternation

between evaporation and precipitation

Most water returned to the atmosphere comes from evaporation from the oceans

Water Cycle ProcessesWater vapor- gaseous form of water in

atmosphereEvaporation- liquid water from bodies of

water becomes gas returned to atmosphere

Transpiration- loss of water by land plants

Water Cycle Processes

Condensation- process which water molecules gather in atmosphere “change from gas to liquid” when cooled

Precipitation- water falls from atmosphere to ground (rain, snow, sleet, or hail )

Water CycleWhat is missing here?

Why is the water cycle important?

Water is the most important nonliving (abiotic) component of an ecosystem

Water essentially determines what organisms we find in an ecosystem Tropical rainforest vs.

desert

Carbon Cycle

Carbon cycles between the living organisms and the non-living components of ecosystem

Carbon exists in the atmosphere as carbon dioxide (CO2)

Plants are of great importance to the carbon cycle!!—photosynthesis takes carbon from the air and creates glucose for all consumers to use

Why do living things need carbon?

C12.011Carbon

6

Carbon Cycle Processes

Photosynthesis- process where sunlight, CO2 and H2O is used to make carbs.

CO2 + H2O + sunlight (energy) glucose (carb) +O2

Respiration- process by which animals use carbs, taking in O2 given off by plants and give off CO2

***THE OPPOSITE OF PHOTOSYNTHESIS!glucose (carb) + O2 CO2 + H2O + energy to live

Respiration The energy for life’s processes comes from cellular

respiration, which occurs in your mitochondriaglucose (carb) + O2 CO2 + H2O + ATP energy

This carbon that you exhale is from the food you eat

Carbon that you eat is used to build other organic macromolecules or is exhaled

Carbon Cycle Processes

Decomposition—breakdown of dead organisms and waste, returning carbon to the soil and atmosphere

Fossil fuels- formed by pressure applied to dead organisms that are buried in sediment. They are carbon and release CO2 when burned.

Combustion- burning of fossil fuels

Carbon Cycle

Why is the carbon cycle important?

Organic macromolecules – carbon compounds used for energy for living organisms (carbohydrates), cell membranes (lipids), DNA/RNA, and proteins.

***Humans are altering this cycle Deforestation releases stored carbon CO2 from burning is a greenhouse gas which

warms the planet

Why is the carbon cycle important?

Burning too many fossil fuels releases extra CO2 into the atmosphere

This creates climate change due to increased greenhouse effect

The greenhouse effect is normal

Climate change is due to abnormally high levels of the greenhouse effec

Greenhouse effect video clip

Average Temperature Over Past Average Temperature Over Past 130 Years130 Years

Year

Ave

rag

e S

urf

ace

Tem

per

atu

re (

°C)

1860 1880 1900 1920 1940 1960 1980 2000 2020

13.6

13.8

14.0

14.2

14.4

14.6

14.8

15.0

What is the Scientific Consensus?What is the Scientific Consensus? Mean global temperature rose about 0.6º C (1.5º F) since 1880

Increase is real, not explained by natural variation in solar radiation

Warming greater at poles than equator, greater at night, mostly troposphere

September sea ice level animation

1979--NASA

2003--NASA

How competition effects ecosystems

Sometimes two species will competeCompetitive exclusion- no two species can

occupy the exact same niche (job) for a long period time

Only one species wins

What if no one wins?

In some species interactions, neither species wins

This results in close, long term associations within an ecosystem called symbiotic relationships

3 Kinds of Symbiotic Relationships+=helped

- = harmed0=neitherParasitism (+/-)

Commensalism (+/0)

Mutualism (+/+)

Evolution and EcologySymbiotic relationships

cause species to evolve in response to each other

Ex) Flowers pollinated by nocturnal moths

Coevolution- evolution of two or more species in response to one another

Ant and Fungus Symbiosis

• Infer….what do you think is the story behind the picture?

• Changes are a natural part of any ecosystem• Succession- regular development of an ecosystem

which leads to gradual replacing of species in a community by others

• Succession and the Mount

Changing Ecosystems

Ecosystem StabilityDoes succession ever end? Climax communityStability - ability of an ecosystem to resist

change when a disturbance occursBiodiversity tends to promote stability

Ecosystem StabilityKeystone species-

species that are crucial to the stability of an ecosystem

If members of a keystone species die, then the entire ecosystem can collapse

i.e. sea otters- keep sea urchins in check, which would take over the kelp beds without the otters

Ecosystem StabilityInvasive, or introduced

species- those that are brought by humans accidentally or purposefully from other places

Invasive/introduced species can take hold and destroy ecosystems.

They multiply out of control due to lack of predators in new place they are moved to.

Ex: Asian longhorn beetle, Zebra mussels

SEA LAMPREY

Population Dynamics

Population-a group of organisms of the same species that occupy a given area

Living things reproduce If environmental conditions are

“favorable,” then the number of individuals in population should increase from one generation to next

Population Size- Growth Rate

Birth rate- # individuals bornDeath rate- # individuals dieImmigration- # individuals move inEmigration- # individuals move outIf… BR + I = DR + E EQUILIBRIUM BR + I > DR + E INCREASING BR + I < DR + E DECREASING Population growth video clip

Biotic PotentialUnder favorable

conditions, a species may reach its biotic potential

Biotic potential- highest reproduction rate possible for a species under “ideal” conditions. Ex) Houseflies-Lay over 100 eggs at once-Can reproduce at 1 month old-After 7 generations, one fly = 15 billion flies!!!

Exponential GrowthExponential

growth- starts out slowly but then grows rapidly to infinitely high numbers

Represented by “J curve”

This does NOT describe real populations forever

Something always limits growth eventually

bioticpotential

Factors Affect Growth Rate Size of Population

Environmental resistance- “limiting factors” that stop populations from reaching their biotic potential Space Water Nutrients Competition Disease Natural disasters

Real populations can only grow exponentially for short spans.

Environmental resistance limits size of a population.

Logistic curve-population growth that levels off due to environmental resistance

“S” curve

Logistic Growth

Carrying Capacity Carrying capacity-

total # of individuals that can be supported by the environment in a particular area

Earth has over 7 billion people…how many more can it support?

Population Crash

The Human Population World Populaton Clock

The human population is growing exponentially at 1% a year

Adding 1 million people every 5 days

Remember that exponential growth cannot continue forever

Humans are subject to the same laws of nature as all other species

Problems with Overpopulation

Humans, more than anything else, are affecting the stability of Earth

1.) Food supply increased over past few decades, but amount per person has decreased

Many people starving, and this will continue to get worse as over 90% of future population growth is expected to occur in less developed nations

Over-fishing Erosion and pollution of agricultural land

Problems with Overpopulation

2.)Energy shortage Nonrenewable resources

are limited and we are using them faster than ever before• Less developed

nations who are developing will continue to use more fossil fuels

• The U.S., with 5% of the world’s population, uses 25% of the world’s energy resources

• Pollutants are increasing as well as climate change

Problems with Overpopulation

3.)Destruction and abuse of natural resources

Topsoil Forests Freshwater supplies diminished Species extinction

Problems with Overpopulation

4.)Pollution• Production of tons of

unnecessary solid waste• Water• Air

– Climate change due to burning and deforestation increasing carbon dioxide levels

– Acid rain– Ozone depletion

Ozone Layer DepletionOzone shield

Ozone (O3) in the atmosphere protects us by absorbing harmful UV light

1970s scientists discovered the ozone layer over Antarctica has decreased by as much as 60 %

Problems? UV light is a mutagen, which

can cause skin cancer Cataracts