Ch. 47 Species interactions, communities, and ecosystems

Question 1

niche

Answer 1

multidimensional habitat that allows a species to practice its way of life

(biotic and abiotic factors)

Question 2

resource partitioning

Answer 2

When species divide a niche to avoid competition for resources

Question 3

fundamental niche

Answer 3

full range of climate conditions/food resources that permits individuals in a species to live (bigger than realized niche)

Question 4

realized niche

Answer 4

actual range of habitats occupied by a species (smaller than fundamental niche)

Question 5

niche vs habitat

Answer 5

niche: “profession”
habitat: “address”

Question 6

community characteristics

Answer 6

• species present
• how species interact
• abundance of each species

Question 7

symbioses

Answer 7

close interaction between species that have evolved over long periods of time

Question 8

mutualisms

Answer 8

mutually beneficial interactions
(flowers and bees)
-can change at any time, these are loosely-bound interactions

Question 9

antagonisms

Answer 9

one sided interactions

-at least one participant loses more than it gains

Question 10

competition

Answer 10

occurs when there are not enough resources to satisfy the individuals who seek them
-always a lose-lose situation
(a grass and a wildflower, each loses nutrients/water/land that the other one takes)

Question 11

competitive exclusion

Answer 11

one species is prevented form occupying a particular habitat or niche due to such competition
-over time this leads to resource partitioning

Question 12

obligate mutualisms

Answer 12

when one or both sides of a mutualism cannot survive without the other
(ex. aphids and the nutrient-producing bacteria who live inside of them)

Question 13

facultative mutualisms

Answer 13

when both sides of the mutualism are capable of surviving without each other

Question 14

commensalism

Answer 14

one partner benefits and the other is unaffected

egrets and cattle, barnacles and whales

Question 15

amensalism

Answer 15

one partner is harmed, other unaffected

Question 16

community

Answer 16

all the populations that live and interact in a given place

Question 17

3 ecologically important mutualisms for humans

Answer 17

1. termites harbor ciliates that produce cellulase, digests wood
2. single-celled algae that produce nutrients for corals (basis of food chain for entire ocean ecosystem!) seafood is a major industry!
3. bees and pollination (crops!) $28 billion industry

Question 18

keystone species

Answer 18

critically important species (usually a predator that keeps populations at bay)

(ex. sea star regulates mussel populations, otters regulate sea urchin populations, beavers create habitat for others)

Question 19

climax community

Answer 19

stable, long lived k-strategists that make up a community

-from here on, there is little change in species composition

Question 20

ecosystem

Answer 20

community of organisms and the physical environment they occupy

Question 21

quickly summarize the food web

Answer 21

primary producers (photosynthetic/chemosynthetic organisms)

primary consumers (herbivores)

secondary consumers (carnivores that eat herbivores)

tertiary consumers (eat secondary consumers)

*about 10% of the biomass of each trophic level is passed on to the next higher level

Question 22

succession

Answer 22

is the sequence of changes in community structure after disturbance