Ecology: Community Eco

Question 2

Individualistic hypothesis

Answer 2

Communities assemble by chance of species with similar abiotic requirements

Question 3

Interactive hypothesis

Answer 3

Communities assemble by chance of closely linked species

Question 4

Tropic levels are defined by

Answer 4

The number of steps though which energy passes to reach organisms in it

Question 5

List basic steps of trophic levels

Answer 5

Primary producer-autotrophsPrimary consumersSecondary consumersTertiaryQuaternary

Question 6

Ecological pyramid measures

Answer 6

Biomass- measure of weight of tissues

Question 7

Energy pyramid describes

Answer 7

The transfer of energy between trophic levels. Only 10% gets consumed from lv to lv

Question 8

Top-down effect

Answer 8

Abundance of lower trophic levels depends on consumers

Question 9

Bottom-up effect

Answer 9

Abundance of higher levels depends on lower lvs/ producers

Question 10

Trophic cascade

Answer 10

When a level is changed (ex population) it sends a cascade of effects trough the chain (usually alternating in increasing/decreasing of other levels)

Question 11

Species richness

Answer 11

Number of (different) species in a community

Question 12

Species evenness

Answer 12

The relative abundance of species (to each other) in a community

Question 13

Species diversity =

Answer 13

Sp evenness + sp richness

Question 14

For any given sp richness, diversity (H) increases with

Answer 14

Species evenness and vice versa

Question 15

Communities with very high or low disturbance have _____ species diversity than communities with moderate disturbance

Answer 15

Lower

Question 16

Good colonizers are

Answer 16

R-selected

Question 17

Good competitors

Answer 17

K-selected

Question 18

Species diversity is highest here disturbance is moderate because

Answer 18

It allows both colonizers and competitors to coexist (K+r)

Question 19

Good competitors (K) reside on the _____ side of the curve

Answer 19

Left side

Question 20

Colonizers (r) reside alone on the ______ side of the curve

Answer 20

Right

Question 21

Communities are adapted to a specific frequency and intensity of disturbance.

Answer 21

True, ex: adaptations to moderate fires

Question 22

Diversity-stability hypothesis

Answer 22

1. Disturbances in diverse communities is dampened by large # of interactions2. The effect of disturbance is less than it would be in a species community without diversity

Question 23

Succession

Answer 23

Transition in species composition over time

Question 24

Primary succession

Answer 24

Bare soil, no organisms

Question 25

Secondary succession

Answer 25

Organisms present with soil

Question 26

Successional pathway

Answer 26

Good colonizers exist earlyGood competitors exist later (near K)

Question 27

Directional succession

Answer 27

Progressive change in species comp

Question 28

Cyclical succession

Answer 28

Change which in the end results in the original community

Question 29

Invasive species

Answer 29

Species that disrupt communities and suddenly become the dominant species.Changes ecosystem structure and function

Question 30

Invasive species means that it is non-native

Answer 30

False

Question 31

Environmental disturbance promotes ______ which can alter ______ and promote even ___-

Answer 31

Biological invasionMore invasion