Lecture 3-Biotic factors that limit species distribution

Question 1

What are the different types of dispersals

Answer 1

Diffusion or passive dispersal
Jump or assisted dispersal
Secular dispersal

Question 2

What is diffusion dispersal?

Answer 2

The gradual dispersal of a population across hospitable terrain over a period of generations.

Question 3

What is jump dispersal

Answer 3

The dispersal across large distances of often inhospitable terrain by individual organisms. often includes assistance by a dispersal agent.

Question 4

What is secular dispersal?

Answer 4

The diffusion over evolutionary time, where the species is undergoing evolutionary change during dispersal. ex. different song sparrows along pacific coast of NA

Question 5

What are barriers to dispersal?

Answer 5

1. Physical barriers (mountains, oceans)
2. behavioral/ecological boundaries (predators, competitors,
3. Physiological barriers (temperature, salinity, climate conditions)

Question 6

What is colonization?

Answer 6

process of dispersing organisms becoming established in new areas. successful colonization requires that conditions in the new area are suitable for the species.

Question 7

how do conditions become suitable for colonization?

Answer 7

1. Disturbance events can create suitable niches where they did not exist previously
2. A species fills and unoccupied niche or out competes existing species. (typical with jump dispersal)

Question 8

What is the tens rule?

Answer 8

1/10 imported species becomes introduced (found in wild). 1/10 of those becomes established (self sustaining pop in the wild) and 1/10 of those becomes invasive or a pest species.
1/1000 imported species become invasive

Question 9

What is the difference between habitat use and habitat preference?

Answer 9

habitat use is when a species is seen at lest once in association with a habitat feature
habitat preference is when a certain species uses something disproportionately to its availability.

Question 10

how do patterns of habitat selection evolve?

Answer 10

species tend to use habitat that maximizes fitness for survival and reproduction. offspring will inherit the tendancy to select similar habitat features.

Question 11

do species occupy all potential spaces?

Answer 11

Not all species occupy all of thier potential range because of competition with other species

Question 12

What is direct competition interactions?

Answer 12

When one species excludes another from some sights by interfering with their usage

Question 13

What is exploitation competition?

Answer 13

When two species use the same resources, but do not interact directly. one species outcompetes the other for those resources

Question 14

What is ideal Free Distribution?

Answer 14

1. Individuals are aware of each site, so they can choose the ideal site.
2. individuals are free to more unhindered among sites because they are competitively equal
3. more individuals in an area, lower quality/smaller portions

Question 15

What does IFD predict?

Answer 15

That animals will distribute themselves among sites in proportion to the amount of resources in each site.

Question 16

What is Ideal despotic Distribution?

Answer 16

Individuals are NOT FREE to move among all sites because they are not competitively equal. some are superior and inhibit movements of inferior individuals

Question 17

What does IDD predict?

Answer 17

That more competitive individuals will dominate less competitive individuals from the best sites.

Question 18

What is Allelopathy?

Answer 18

When one species produces a toxin or chemical that inhibits the growth of another species. Can also be used in agriculture with smother crops to reduce weed over growth

Question 19

Does predation limit species distributions

Answer 19

yes, but this occurs mainly at relatively small scales ( on a site-by-site basis)

Question 20

do disease and parasites limit species distributions?

Answer 20

yes, but this differs from predation and occurs mainly at larger scale.