Ecology Lectures 4 - 6

Question 1

Define: COMPETITION

Answer 1

the INTERACTION between species where and INCREASED growth rate for ONE means a DECREASED growth rate for the OTHER

Question 2

Define: COMPETATIVE EXCULSION PRINCIPLE

Answer 2

when two species have IDENTICAL species, one will drive the other to EXTINCTION

Question 3

Define: EXPLOITATAIVE COMPETITION

Answer 3

“INDIRECT” competition between species or individuals for LIMITED RESOURCES in an environment

Question 4

Define: INTERFERANCE COMPETITION

Answer 4

“DIRECT” competition between species or individuals that IMPEDE on a competitor’s ACCESS to essential RESOURCES.

Question 5

Define: COEXISTENCE AT A REDUCED CAPACITY

Answer 5

both species continue to LIVE, at LOWER numbers. this is TEMPORARY.

Question 6

Define: COMPETATIVE EXCLUSION

Answer 6

one species DISAPPEARS from the region. the species BETTER ADAPTED to the NICHE of the environment will SURVIVE.

Question 7

Define: NICHE PARTITIONING

Answer 7

both species continue to COEXIST, but they DIVERGE slightly to occupy SLIGHTLY different environmental NICHES (new REALIZED NICHE).

Question 8

Define: CHARACTER DISPLACEMENT

Answer 8

when NICHE PARTITIONING leads to EVOLUTIONARY change

Question 9

Define: MUTUALISM

Answer 9

interactions where BOTH species are BENEFITTED.

Question 10

Define: CONSUMPTION

Answer 10

one species BENEFITS and the other is HARMED (ex. predation, parasitism, herbivory)

Question 11

Define: COMMENSALISM
(hint: sounds like communism)

Answer 11

one species is BENEFITED, the other is NOT AFFECTED

Question 12

Define: AMENSALISM

Answer 12

one species is HARMED, the other is NOT AFFECTED

Question 13

Define: ECOLOGICAL NETWORKS

Answer 13

a REPRESENTATION of the BIOTIC INTERACTIONS between species

Question 14

Define: TOPOLOGY
(Hint: who’s on top?)

Answer 14

who EATS whom.

Question 15

Define MODULE

Answer 15

SUBSET of species within a web.

Question 16

Give examples of INDIRECT species interactions.

Answer 16

1. humans are PREDATORS to the environment
2. INCREASED predator ABUNDANCE caused DECREASED prey ABUNDANCE
3. INCREASED prey ABUNDANCE caused INCREASED predator abundance

Question 17

Define: TROPHIC TRANSFER

Answer 17

elements, energy, and contaminants are TRANSFERRED from one trophic LEVEL to ANOTHER.

Question 18

Define: BIOACCUMULATION

Answer 18

the gradual BUILD UP of substances, such as toxins or contaminants, in the TISSUE or ORGANS in species over time.

Question 19

Define: BIOMAGNIFICATION

Answer 19

occurs when the CONCENTRATION of substances, such as contaminants and toxins, INCREASES as you move UP the FOOD CHAIN

Question 20

Define: FOOD CHAIN

Answer 20

LINEAR sequence of ENERGY FLOW between organisms

Question 21

Define: TROPHIC LEVEL

Answer 21

a POSITION on the food chain that represents a group of organisms sharing the SAME ENERGY SOURCE

Question 22

Define: BIOMASS

Answer 22

the TOTAL quantity or weight of organism in an AREA

Question 23

Define: TROPHIC PYRAMID

Answer 23

relative amounts of BIOMASS within each TROPHIC LEVEL of the FOOD CHAIN

Question 24

What is the principle of ecological efficiency?

Answer 24

only a FRACTION of the ENERGY and BIOMASS from each trophic level is PASSED UP the pyramid (~10%)

Question 25

Define: ECOLOGICAL NETWORK

Answer 25

a representation of the BOTIC INTERACTIONS in an ecosystem

Question 26

What are the four cycles in an ecosystem

Answer 26

1. nutrients (primary producer –> primary consumer –> top predator –> decomposer –> primary producer)
2. carbon
3. nitrogen
4. phosphorus

Question 27

How do nutrient and energy interactions differ in a system?

Answer 27

nutrients cycle, energy flows (linear)

Question 28

Define: STABILITY

Answer 28

the maintenance of a RELATIVELY CONSTANT population SIZE of a species in a geographical area

Question 29

What type of ecosystems tend to be more stable?

Answer 29

complex, diverse ecosystems are more stable and have a faster return time (eg. a forest is more stable than a farm)

Question 30

Define: PERTURBATION

Answer 30

a CHANGE in an ecosystem that DISRUPTS its normal or FUNCTIONAL STATE

Question 31

What type of ecosystems have stronger interactions (stable or nonstable)?

Answer 31

NONSTABLE

stable interactions are weak, which is why disruption can easily be spread across the web and not disrupt the whole ecosystem.