Chapter 15- Mutualism and Commensalism

Cheaters

Individuals increase their production of offspring by/through the process of overexploiting their mutualistic partner.

Commensalism

Is an interaction in which individuals of one species benefit while those of the other species do not benefit and are not harmed (+/0 relationship)

Facilitation

A trophic or non-trophic species interaction in which one or both species benefit and neither is harmed.

Habitat mutalisms

One partner provides the other with shelter, living space, or favorable habitat.

Mutualism

It is a Mutually beneficial interaction between individuals of two species, meaning that both benefit equally

Positive interactions

Are interactions that in which one or both species benefit and neither is harmed.

Symbiosis

Two species live in close physiological contact with each other.

Trophic mutualisms

Mutualist receives energy or nutrients from its partner.

Ectomycorrhizae

The fungus grows between root cells and forms a mantle around the root.

Arbuscular mycorrhizae

The fungus penetrates the cell walls of some root cells

Arbuscular mycorrhizae form a branched network called a?

Arbuscule.

“Most Plants form”?

Mycorrhizae

What are “Mycorrhizae”?

Symbiotic associations between the roots and various fungi.

What do the “Fungi” do for “Plants” in “Positive interactions”?

It increases the surface area for the plant to take up water and soil nutrients (over 3 m of fungal hyphae may extend from 1 cm of plant root).

What do the “Plants” do for “Fungi” in “Positive interactions”?

They supply the fungi with “carbohydrates”.

Explain “What is Coral Bleaching”?

It occurs when coral polyps expel algae that live inside their tissues.

“What are the causes of Coral Bleaching”?

1.) Increasing temperature

2.) Pollution (nutrients, sediments)

3.) Increased exposure to sun and air

What “Positive Interaction” does “Spanish Moss” do?

1.) Absorbs pollutants (used as environmental indicators)

2.) Creates habitat

“Interactions and the balance between cost and benefits can…?”

Vary in space and time

“When interactions no longer provide a net benefit they….?”

May cease to occur

“Positive interactions may be more common in….?”

Stressful environments (e.g., high elevations, intertidal zone, wetlands, etc.)

Explain the “Relative neighbor effect (RNE)”

Target species’ performance with neighbors present minus its performance with neighbors removed.

What are the “Three Types of Mutualisms”?

1.) Trophic mutualism

2.) Habitat mutualismm

3.) Service mutualism

Service mutualisms

One partner performs an ecological service for the other.

What are/explain some of the “Services” that “Service mutualism” include?

1.) Pollination

2.) Dispersal

3.) Defense against herbivores, predators, or parasites.

Why are “Mutualists” not considered “Altruistic”?

Because in reality they are in it for their own benefit.

Although there are “Costs” involved in Mutualism, like giving up nutrients or space in order for this relationship to persist what must occur?

Net benefits must exceed net costs.

If there is “Overexploitation” in a “Mutualistic Relationship” often caused bu a “Cheater” what may happen?

The interaction will probably not persist or “Penalties” may be imposed on cheaters

Provide an example of a “Cheating Relationship”

Yuca Moths leave too many eggs, and the large ones consume too many seeds.