Bell Ringer



1.
Can a food web or food chain ever show abiotic factors?
2.
A food web shows life at the [population, community, ecosystem] level. (Pick one.)
3.
Can an energy pyramid ever be inverted?
4.
How much energy passes from one trophic level to the next?
5.
Can a biomass pyramid ever be inverted?

So, how do all those organisms live together?

What shapes an Ecosystem?

 Ecosystems are defined by the interactions among the biotic and abiotic factors that exist within.
 The two major factors that these interactions influence are:
 How organisms survive and thrive.
 The overall productivity of the ecosystem.

What shapes an Ecosystem?

 The area where an organism lives is called its
habitat. An organism’s habitat can also include a host body, in the case of parasites.
 The “role” that an organism plays in its habitat is called a niche. An organism’s niche includes:
 The conditions in which an organism lives.
 The means by which an organism survives.

What shapes an Ecosystem?

 For example, a bullfrog’s habitat would be a pond, lake or stream, as well as the land nearby.
 A bullfrog’s niche would be:
 The food it eats, and is eaten by.
 The cold, watery environment it lives in.
 The means by which it maintains body temp.
 The means by which it reproduces.

Community Interactions

 Organisms that live within the same ecosystem interact with each other on a constant basis.
 These interactions may or may not be beneficial, to either party.

Community Interactions

 Competition: This interaction occurs when two organisms fight over the use of one resource at the same time.
 The organisms may
OR may not be of the same species!

Community Interactions

 The competitive exclusion principle states that no two species can occupy the same niche in the same habitat at the same time.
 This principle means that different species will go out of their way to avoid competing with one another.
 This is because competition might lead to death for the loser!

Community Interactions


Community Interactions
 Predation: An interaction in which one organism
ACTIVELY hunts and eats another.

 Both predator and prey evolve adaptations to help them survive.

Community Interactions
 Symbiosis: ANY relationship where two organisms live closely together.

 This means the two organisms are NOT trying to kill each other…
 Although there may still be negative effects!

Community Interactions

 There are three possible symbiotic relationships:
 Mutualism, where both organisms benefit.
 Commensalism, where one organism benefits, and the other is unaffected.
 Parasitism, where one organism benefits, and the other is harmed.

Community Interactions

Symbiotic
Relationship
What happens to organism 1?
What happens to organism 2?
Mutualism
Commensalism
Parasitism
Benefits (+)
Benefits (+)
Benefits (+)
Benefits (+)
Unaffected (=)
Harmed (-)

Exit Ticket

1.
The role that an organism plays in its environment is its _______.
2.
Can two different species occupy the same ecological niche? Why or why not?
3.
Two male deer are butting heads over territory.
What is this an example of?
4.
Barnacles attach themselves to a whale to move around, and the whale is neither helped or harmed.
What is this an example of?

Ecological Succession

 Ecosystems do NOT stay constant over time.
They will change in response to both abrupt and gradual changes in the environment.
 As an ecosystem changes, older inhabitants die out, and new ones replace them. This causes the local community to continually evolve.
 We call this process ecological succession.

Ecological Succession

 The type of succession that occurs depends on whether soil already exists or not.
 If NO soil exists, primary succession occurs.
 This happens right after a volcanic eruption, or after glaciers melt.
 If soil already exists, secondary succession occurs.
 This happens when farmland is abandoned, or after a wildfire.

Ecological Succession

 In primary succession, there is no soil to start; just ash and rock.
1.
First, pioneer species (often lichens) populate the area. They break up the rocks to form soil.
2.
These species die, which provides nutrients to the soil. They are eventually replaced with new plants.

Ecological Succession

 In secondary succession, good soil already exists. Only the wildlife is replaced.
1.
First, small shrubs and grasses appear.
2.
Small bushes and evergreen trees develop first.
3.
Eventually, the evergreens are overtaken by larger deciduous trees.

Ecological Succession

 Marine ecosystems are also prone to ecological succession.
 This can take the form of tectonic upheaval, of temperature changes, or of the addition of new communities or habitats.

Exit Ticket

1.
A dog is infested with fleas, which feed of the skin and blood of the dog. What is this an example of?
2.
What type of succession will occur after: a.
a wildfire?
b.
a glacier melts?
c.
a swarm of locusts eats most of the vegetation?


 Answer true or false to all statements.
1.
Competition only occurs between members of the same species.
2.
Symbiosis includes mutualism, commensalism and parasitism.
3.
Ants move aphids to new leaves, while aphids produce food the ants like. This is an example of mutualism.
4.
The appearance of pioneer species is the first step of primary succession.
5.
Secondary succession only occurs when there is no soil.