BIOL 122: Biotic Interactions (EXAM 4) 2nd

What is a Niche?

How an organism uses resources. (Basically, an organism's job within a certain habitat).

-Hypothetical space an organism occupies in a system.

-Includes:

1) Dietary (What it eats).

2) Spatial (Where it lives).

3) Temporal (When its active).

Interactions between species play ____________ roles in communities.

Important.

What do Community Ecologists Study?

They study Interspecific Interactions.

What are Interspecific Interactions?

Relationships between species, classified according to how they affect each population involved.

What are the Types of Interspecific Interaction?

1) Competition.

2) Mutualism.

3) Predation.

4) Herbivory.

5) Parasitism/Pathogens.

What is Competition?

Competition is a type of interspecific interaction that is mutually harmful to both species involved.

-Competition may occur when two or more species in a community rely on similar limiting resources.

What does the Competitive Exclusion Principle say about two species that need the same resources?

If the resources required by two species are too similar, they cannot coexist.

What is Mutualism?

Mutualism is a form of interspecies interaction in which both species benefit.

-It often occurs among species that are symbiotic, living in close physical association with one another, but not all symbiotic relationships are mutual.

What does Symbiotic mean?

Two different species living closely together in a way that affects both of them.

What is Predation?

A type of interspecies interaction in which a predator species kills and eats a prey species.

-An interaction in which it is beneficial to one species and harmful to the other.

What is Herbivory?

Animals eating parts of plants.

-An interaction in which it is beneficial to one species and harmful to the other.

What is a Parasite?

An organism that lives on or in (but does not kill) a host, from which it obtains nutrients.

-An interaction in which it is beneficial to one species and harmful to the other.

What is a Pathogen?

Are disease-causing microorganisms.

-An interaction in which it is beneficial to one species and harmful to the other.

Food Webs describe multiple ___________ __________.

Trophic Structures.

What are Tropic Structures?

Structures that describe the feeding relationships within a community.

________ ________ and ________ ________ describe the transfer of organic material from one trophic level to the next.

1) Food Chains.

2) Food Webs.

What is a Food Chain?

A simplified description of one part of the trophic structure.

The Trophic Structure of an ecosystem describes the __________ __________.

Feeding Relationships.

What are the Trophic Levels?

0) Decomposers (Fungi, ETC - breaks down nonliving matter).

1) Primary Producers (Plants).

2) Primary Consumers (Herbivores).

3) Secondary Consumers (Predators that eat Herbivores).

4) Tertiary Consumers (Top Predators that eat other Predators).

**Energy enters an ecosystem as sunlight.

**At each energy conversion heat is released.

**Energy FLOWS through Ecosystems.

What do Primary Producers do?

Convert solar energy to chemical energy via photosynthesis.

-Your plants.

What are Primary Consumers?

Are herbivores that eat primary producers.

-Your rabbits and sh!t.

What are Secondary Consumers?

Are Predators that eat Primary Consumers.

-Your wolves, ETC.

What are Tertiary Consumers?

Are top level predators that eat other predators.

-As trophic levels increase, less energy is available at each transfer; therefore, these mfs need to consume a lot to have energy.

What are Decomposers?

Are organisms that break down nonliving matter and make it into nutrients and stuff like that for Primary Producers.

-Death at any level sends energy to the decomposers.

A Food Web interconnects multiple ______ ______.

Food Chains.

-A food web of a hypothetical forest community.

-Arrows indicate energy transfer or "who eats whom."

What is Biological Magnification?

The tendency of toxins to become concentrated as they pass through a food chain.

-Toxins can accumulate in higher levels.

Species Diversity includes both ________ ________ and _________ _________.

1) Species Richness.

2) Relative Abundance.

What is a Species Richness?

The number of different species in an area.

What is Relative Abundance?

How common each species is compared to the others in the same area or the fraction accounted for by each species.

What is a Keystone Species?

A species that has a disproportionately large effect on its environment relative to its abundance.

-Can drive diversity.

-Ecologists studying the Alaskan coast discovered that a decline in the sea otter population allowed sea urchins to quickly multiply --> devouring of kelp forest.

What is Primary Succession?

When life begins to grow in a place that starts with no soil and almost no living things — like bare rock.

-1st multicellular life to return is often photosynthetic lichens & mosses, followed by small plants.

What is Secondary Succession?

When an ecosystem regrows after a disturbance, but the soil is still there.

What is Ecological Succession?

After a disturbance, an area will be reoccupied by a series of species.

-The natural process of how an ecosystem changes and rebuilds itself over time.

What is an Invasive Species?

A species that is not native to an area and spreads quickly, causing harm to the environment, other species, or human activities.

-Invasive species disrupt ecosystems.

-Invasive species are now a leading cause of extinctions of local populations.

EX) Lionfish.

Caulerpa Taxifolia

A type of invasive green algae.

-Originally from the Monaco Aquarium.

-Released into the Mediterranean.

-Can spread through fragmentation.

-Poisonous to many organisms.

-Fast growing.

(I will be damned if this mf asks a question about ts).

What are some Invasive Species?

1) Burmese Python.

2) Kudzu Climbing Vine.

3) Alligator Weed.

4) Giant Salvinia.

5) Hydrilla.

6) Water Hyacinth.

7) Chinese Tallow.

8) Wild Taro.

9) Wild Boar.

10) Nutria.

(Again, I will be DAMNED if he asks about this).

What is Biological Control?

The release of a natural enemy to an invasive species to combat them.

-Ecologists may implement biological control, the intentional release of a natural enemy.

-Biological control species must be closely studied.

+Mongooses were introduced to Hawaii to eat rats --> they also decimated many native species.

An example of out-of-control Biological Control:

-Guam's snake problem is a classic example of a biological control gone wrong.

+Brown tree snakes were accidentally introduced to Guam.

+These snakes have no natural predators on the island, so their population exploded.

+They ate many native birds and lizards, causing several species to go extinct.

=So, like the mongoose example in Hawaii, introducing or having a predator without proper checks can disrupt the local ecosystem.

What is Integrated Pest Management?

A method to control pests that utilizes several strategies:

-Biological control.

-Pest-resistant crop varieties.

-Judicious use of chemicals.

-Release of sterile pests.

-Other biological and behavioral changes.

-Modern agriculture presents unique challenges of biological control.

Sanity Check