Community Ecology

Question 1

variety of organisms that make up a community

Answer 1

species diversity

Question 2

2 components of species diversity

Answer 2

species richness and relative abundance

Question 3

number of species in a community

Answer 3

species richness

Question 4

proportion each species represents

Answer 4

relative abundance

Question 5

Characteristics of communities with higher diversity

Answer 5

• more productive
• more stable in their productivity
• able to produce biomass more consistently
• cope better with environmental stress
• more resistant to invasive species

Question 6

Biogeographic factors that affect community diversity

Answer 6

latitudinal gradients and area effects

Question 7

species richness is high in the ______ and declines towards the ______

Answer 7

tropics; poles

Question 8

Why is species richness age in the tropics and declines towards the poles?

Answer 8

age of environment
length of growing season

Question 9

Larger geographic areas tend to have _____ species.

Answer 9

more

Question 10

relationships between species in a community

Answer 10

interspecific interactions

Question 11

Examples of interspecific interactions

Answer 11

• competitions
• predation
• symbiosis

Question 12

when species compete for a resource that limits their growth or survival

Answer 12

competition

Question 13

local elimination of a competing species

Answer 13

competitive exclusion

Question 14

two species competing for the same resources cannot coexist in the same place

Answer 14

competitive exclusion principle

Question 15

specific set of biotic and abiotic resources used by an organism

Answer 15

ecological nuche

Question 16

species exhibiting a specific ecological niche that enables similar species to coexist

Answer 16

resource partitioning

Question 17

the niche potentially occupied by that species

Answer 17

fundamental niche

Question 18

the niche actually occupied by that species

Answer 18

realized niche

Question 19

characteristics become divergent in sympatric populations

Answer 19

character displacement

Question 20

feeding relationships between organisms

Answer 20

trophic structure

Question 21

food _____ link trophic levels from producers to top carnivores in a, usually, vertical manner

Answer 21

chain

Question 22

food ____ is a branching food chain with complex trophic interaction

Answer 22

web

Question 23

most abundant species or have the highest biomass

Answer 23

dominant species

Question 24

exert strong control on a community by their ecological roles

Answer 24

keystone species

Question 25

cause physical change int he environment that affect community structure

Answer 25

ecosystem engineers

Question 26

undirectional influence from lower to higher trophic level

Answer 26

bottom-up model

Question 27

In a bottom-up model, the presence or absence of _________ determine community structure

Answer 27

mineral nutrients

Question 28

control comes form the trophic level above

Answer 28

top-down model

Question 29

used to improve water quality in polluted taxas

Answer 29

biomanipulation

Question 30

species richness on islands depends on:

Answer 30

• island size
• distance form mainland
• immigration
• extinction

Question 31

species richness on an ecological island levels off at a dynamic equilibrium point

Answer 31

equilibrium model of island biogeography