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
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
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
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
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 )
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
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
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
Top Related