The study of the interactions between organisms and their
environment.
Environmental Science: Chapter 18
ecology
community
biotic
ecosystem
population
ecosystem
ecology abiotic
community
biotic
biotic ecosystem
habitat
abiotic population
ecology community
niche biosphere
ecology
Section 1Everything is Connected
Biotic factors:
• All the organisms that live together and interact with one another.
Abiotic factors:
• All of the physical factors (non-living things) that affect organisms
• Examples: water, air, soil , light, temperature, wind, humidity, waves, currents, gravity, etc.
Organism-• An individual form of life
• Anything that can carry out life processes independently
Population-• A group of individuals of the same
species that live together in the same area at the same time.
Community-
All of the populations of different species that live and interact in an area.
Ex. Fawn Lake:
• An ecosystem is made up of a community of organisms and it includes its ABIOTIC environment
• Example: the ocean, tropical rain forest, salt marsh, river, etc.
Biosphere
The part of the earth where life exists.
5 Levels of Environmental Organization:
organismorganism
populationpopulation
communitycommunity
ecosystemecosystem
biospherebiosphere
Salt Marsh Ecosystem:
Cape Cape CodCod
LIVING THINGS NEED ENERGY!
99.9% of living things get their energy from where?
Section 2
Black smokers….feed clams and tube worms…energy here comes from sulfur chemicals inside the earth
These exist on average at depths of 6,890 feet below the surface of the oceans !
Submersible : Alvin
All organisms are either:
•A producer
•A consumer or
•A decomposer
What’s a Producer?
• Organisms that use sunlight directly to make food…
Ex. plants, algae, some bacteria
Producers do this by the process of…
A Consumer
• Is an organism that eats other organisms
– They eat producers (like plants) or
– They eat other animals
What are the four types of Consumers?
Decomposers
• Organisms that get energy by breaking down the remains of dead organisms
• Ex. Bacteria, Fungi
• Known as “nature’s recyclers”
What are the 2 main decomposers?
•Bacteria !
•Fungi !
This chain of energy transferring from one species to another can continue several more times, but it eventually ends. It ends with the dead animals that are broken down and used as food or nutrition by bacteria and fungi. As these organisms, referred to as decomposers, feed from the dead animals, they break down the complex organic compounds into simple nutrients. Decomposers play a very important role in this world because they take care of breaking down (cleaning) many dead material. There are more than 100,000 different types of decomposer organisms! These simpler nutrients are returned to the soil and can be used again by the plants. The energy transformation chain starts all over again.
Names and word definitionsNames and word definitions
Cycle of Life…Cycle of Life…
What’s the difference between a Food Chain
and a Food Web?
•Food Chain-shows how energy in food molecules flows from one organism to the next
•Food Web-a complex diagram showing many energy pathways in a real ecosystem
In a food chain or Food Web:
• The arrow shows the direction of energy movement.
• Which is correct?
• A) Worm Robin
• B) Robin Worm
What two things does an Energy Pyramid
show?
• Number of organisms
• Amount of energy available at each level:
WolvesCanus lupis
• Used to be common throughout the country• They are predators that prey on large animals
such as elk, deer, moose, buffalo, bison• Considered at the top of the Energy Pyramid in
their ecosystem• Almost wiped out as the wilderness was
settled
• Results of their disappearance to the ecosystem?
Complete change of the food web:
• Elk populations increased…– Overgrazing (by elk)– Grasses became wiped out– Populations of animals dependant on grasses
were wiped out (hares, prairie dogs, skunks, chipmunks, and other small mammals)
• Wipe-out of animals like foxes that eat the small mammals
Cervus Cervus americanusamericanus
In 1995
• Wolves were reintroduced to Yellowstone National Park:
How’s a habitat different from a niche?
• Habitat-
•(where it lives)
• Niche-
• (its role within the ecosystem)
Spider
Habitat?
Niche?
Dog
• Habitat?
• Niche?
Maple Tree
• Habitat?
• Niche?
Types of Interactions…
Section 3…
Interactions in the environment…
• Limiting Factors-things that slow the growth of a population such as food, water, or space, sunlight
• Carrying Capacity
Carrying Capacity
• The largest population that an environment can support over a long period of time.
Example in Bedford?…
The deer population !
Carrying Capacity
Oh Deer Game !
Interactions with Other Organisms:
• There are 4 main ways that species and individuals affect each other:
– Predators and Prey– Competition– Symbiosis– Coevolution
Predator-Prey
• One organism eats another:
predator
prey
Adaptations of predators and prey:
• Characteristics that improve an organism’s ability to survive and reproduce
• Ex. Goldenrod spider:– Ambush their prey– Camouflage their bodies
Prey adaptations:
• Warning coloration:
• Schooling in fish• Herding in antelopes, zebras• Camouflage• Chemical defenses
• Two cannibals are eating a clown. One says to the other: "Does this taste funny to you?"
Competition• When 2 or more individuals or populations
try to use the same limited resource such as:
• Food• Water• Shelter• Space • Sunlight• Can occur within a population as well as
between populations of different species
Symbiosis:
•Mutualism
•Commensalism
•Parasitism
Mutualism
•Both organisms benefit:
Coral polyps
algae
bacteria
human intestines
Lives inside
Contain living
clownfish living in anemones
I’m Nemo
I’m Nemo
Commensalism
•One benefits while one is unaffected:
Remora fish live on the underside of sharks
Epiphytes
• Organisms (usually plants) that grow on other plants and do not harm them.
Examples of epiphytes…
•Air plants
Spanish moss
Lichens
•moss
Parasitism
•One benefits while the other is harmed:
•The animal the parasite lives on or in is called the HOST
Fleas, ticks, worms, leeches
Tobacco Hornworm with parasitizing wasp eggs:
No parasitesNo parasites
parasitesparasites parasitesparasites
Coevolution
•The “long-term change” that takes place in two species because of their close interactions with each other.
Example on next slide…
Flowers coevolved with pollinators…
• Hummingbirds and ornithophilous flowers• Hummingbirds and ornithophilous flowers have
evolved to form a mutualistic relationship. It is prevalent in the bird’s biology as well as in the flower’s. Hummingbird flowers have nectar chemistry associated with the bird’s diet. Their color and morphology also coincide with the bird’s vision and morphology. The blooming times of these ornithophilous flowers have also been found to coincide with hummingbirds' breeding seasons.
• Garter snake and Rough-skinned newt• Coevolution can occur between predator and prey
species as in the case of the Rough-skinned Newt (Taricha granulosa) and the common garter snake (Thamnophis sirtalis). In this case, the newts produce a potent nerve toxin that concentrates in their skin. Garter snakes have evolved resistance to this toxin through a set of genetic mutations, and prey upon the newts. The relationship between these animals has resulted in an evolutionary arms race that has driven toxin levels in the newt to extreme levels.
• Acacia ant and Swollen thorn acacia tree
• The ant provides protection for the tree against preying insects and other plants competing for sunlight, and the tree provides nourishment and shelter for the ant and the ants' larvae.[11][12]