Positive Species Interactions

Question 1

Commensalism

Answer 1

individual of one species benefits, the other species is not harmed nor does it benefit (+/0)

Question 2

Mutualism

Answer 2

interactions mutually beneficial for both species (+/+)

Question 3

Symbiosis

Answer 3

Close physical association between a host and an internal symbiont. Can include parasitism (+/-), commensalism, or mutualism.

Question 4

What is the role of ectomycorrhizae and arbuscular mycorrhizae in shaping ecosystems

Answer 4

Both increase the surface area over which a plant can extract water and nutrients and can also create vesicles to store nutrients for the plants. These allow for much more plant life!

Question 5

Facultative mutualism

Answer 5

mutualist can live without mutualistic partner but performs better with it mutualistic partner

Question 6

Obligate mutualism

Answer 6

the mutualist depends on its partner. Survival or reproduction not possible in the absence of the partner

Question 7

Generalist mutualist

Answer 7

multiple species can perform the function (i.e. pollinators)

Question 8

Specialist mutualist

Answer 8

reliant on only one other species

Question 9

trophic mutualist

Answer 9

energy exchanged with the partner (i.e. mycorrhizae)

Question 10

habitat mutualist

Answer 10

provides a place to live for the other partner

Question 11

What are 2 examples of how positive interactions affect the abundances and distributions of populations as well as the structure of ecological communities?

Answer 11

Example 1: mutualistic cleaner fish- the number of fish and number of species is greater when cleaner fish are present
Example 2: if one species provides a home for another (habitat mutualists) then then one species will determine the distribution of the other