Ecological Communities

Question 1

what holds communities together and determines their nature and stability

Answer 1

species interactions

Question 2

Exploitative interactions

Answer 2

Interactions where one member exploits another for its own gain

Question 3

examples of exploitative interactions

Answer 3

1. predation
2. paraistism
3. herbivory

Question 4

7 main categories of species interactions

Answer 4

1. competition
2. predation
3. paratisim
4. communalism
5. Mutualism
6. Herbivory
7. Amensalism

Question 5

competition

Answer 5

occurs when resources are limited

Question 6

describe the effect of competition on two species

Answer 6

each species has a NEGATIVE effect on the OTHER species as each takes resources away from the other

Question 7

describe the effect of PREDATIOn on two species

Answer 7

negative effect on one species while a positive effect on the other

Question 8

describe the effect of parasitism on two species

Answer 8

negative effect on one species and positive on the other

Question 9

describe the effect of herbivory on two species

Answer 9

negative effect on one species and positive on the other

Question 10

describe the effect of mutualism on two species

Answer 10

both species benefit from the interaction

Question 11

describe the effect of commensalism on two species

Answer 11

One species benefits while the other is not affected

Question 12

Amensalism

Answer 12

Variation of competitive relationship where one organisms in harmed and the other is unaffected (not benefiting)

Question 13

intraspecific competition vs interspecific competition

Answer 13

intraspecific:
Competition between members of the same species

interspecific:
Competition between members of different species

Question 14

which type of competition can lead to competition exclusion

Answer 14

interspecific competition

Question 15

competition exclusion

Answer 15

If one species is a better competitor than the other, they might exclude another species from using the resource entirely

Question 16

how does competition create species coexistence

Answer 16

○ When neither competing species fully excludes the other and they can live side by side at a certain ratio of population size

○ Species adjust to their competitors to minimize competition between them

Question 17

fundamental vs realized niche

Answer 17

fundamental:
the full niche of the species

realized:
Individual that plays only part of its role because of competition or other species interactions

Question 18

Resource partitioning

Answer 18

The species in an area divide or partition the resources they use in common by specializing in different ways

Question 19

what can lead to character displacement in species

Answer 19

resource partitioning

Question 20

character displacement

Answer 20

○ Competition species evolve physical characteristics that reflect their reliance on the portion of the resource they use

○ Becoming more different = reduced competition

Question 21

Predation

Answer 21

Process where individuals of one species (predators) hunt and consume other species (prey)

Question 22

what species interaction structure food webs and influence community composition

Answer 22

predation

Question 23

Evolutionary ramifications of predation

Answer 23

○ Predators that are more adept in capturing prey will likely live longer, healthier lives and provide better for offspring

○ Evolutionary adaptions that lead predators to be better hunters

*Prey face selective pressures to avoid predators

Question 24

Parasitism

Answer 24

Relationship where one organisms (the parasite) depends on another (the host) for nourishment, support… While harming the host organism

Question 25

Parasitoids

Answer 25

Insect parasites on other insects which kills them in the process

Question 26

which species interaction results in coevolution

Answer 26

parasitism

Question 27

coevolution

Answer 27

Host and parasite repeatedly evolve new responses to the other's latest advancement

Question 28

Herbivory

Answer 28

Occurs when animals feed on the tissues of plants

Question 29

how does herbivory affect plants

Answer 29

Often does not kill a plant outright but instead affect its growth and reproduction

Question 30

Mutualism

Answer 30

Relationship where two or more species benefit from interacting with each other

Question 31

example of mutualism

Answer 31

symbiosis (Mutualism occurring between organisms that live physically close together)

Question 32

Commensalism

Answer 32

Interaction where one species benefits and the other is unaffected

Question 33

Community

Answer 33

Group of populations of organisms that live in the same area at the same time

Question 34

Ecological communities relates to

Answer 34

Which species coexist how they relate to one another how communities change through time

Question 35

trophic Levels

Answer 35

Rank in the feeding hierarchy of a food chain where organisms at a higher level consume those found at a lower level

Question 36

where does the energy that drives interactions like predation ultimately come from

Answer 36

the sun via photosynthesis

Question 37

first trophic level

Answer 37

producers/autotrophs

Question 38

second trophic level

Answer 38

primary consumers (Consumers that eat producers; herbivores)

Question 39

third trophic level

Answer 39

secondary consumers (Consumers that prey on primary consumers)

Question 40

higher trophic levels (above third)

Answer 40

Tertiary consumers (Predators that eat secondary consumers which eat primary consumers like owls)

Question 41

Detritivores vs decomposers

Answer 41

Detritivores ; Scavenge the waste products or the dead bodies of other community members decomposers ; Break down leaf litter and other nonliving matter further into simpler constituents that can be taken up and used by plants

Question 42

what are detritivores and decomposers known as

Answer 42

saprotrophs

Question 43

where is most of the energy consumed in trophic levels

Answer 43

First trophic level with the producers contain a large amount of energy

Question 44

______ amounts of energy is transferred to higher trophic levels

Answer 44

small

Question 45

which trophic level contains the least amount of energy

Answer 45

tertiary level

Question 46

why is the trophic levels shown in a Trophic pyramid diagram

Answer 46

Pyramid shape because biomass, energy and number of individuals decrease upward through the trophic levels

Question 47

food webs vs food chains

Answer 47

food web: a visual map of feeding relationships and energy flow that shows the many paths energy passes among organisms as they consume each other food chain ; a linear series of feeding relationships which focuses on the movement of energy and distribution of biomass in the system

Question 48

Keystone species

Answer 48

Species that has a particular strong or far-reaching impact where their removal from an ecosystem will alter a large portion of the food web

Question 49

Trophic cascade

Answer 49

Where the disappearance of a top predator leads to dramatic changes at lower trophic levels

Question 50

resistance vs resilience

Answer 50

resistance ; When a community resists change and remain stable despite major disturbances resilience ; The community does change in response to the disturbance but returns to it's original state quickly

Question 51

Succession

Answer 51

A disturbance is sever enough to eliminate all or most of the species in a community that results in a series of changes in the composition and structure of a community

Question 52

importance of pioneer species

Answer 52

Species that arrive first at a primary succession site and colonize the new ground

Question 53

best pioneer species

Answer 53

lichen (part fungi and part algae)

Question 54

Climax community

Answer 54

A community that remains in place with little modification until some disturbance restarts succession

Question 55

two types of succession

Answer 55

primary succession and secondary succession

Question 56

primary succession vs secondary succession

Answer 56

primary succession ; Follows a disturbance that no vegetation or soil life remains from the community meaning It starts with a clean slate and the biotic community is built from scratch (like with volcanic deposits) secondary succession ; A disturbance dramatically alters an existing community but does not destroy all living things or organic matter in the soil (like a fire or flood)

Question 57

Invasive species

Answer 57

A species that spread widely and rapidly becomes dominant in a community and interferes with the community's normal functioning after being introduced to an ecosystem - it is not native

Question 58

when do invasive species become pests

Answer 58

Invasive species where their negative impacts outweigh the benefits

Question 59

Two main characteristics of invasive species

Answer 59

1. ability to spread rapidly and unimpeded in the new environment 2. The negative impact on the native species, communities and ecosystems

Question 60

What role does Natural selection play in predation

Answer 60

has led to adaptions in both prey and predator populations (venom, camouflage, mimicry, chemical detection...)