chapter 54: Community ecology

Question 1

what is a biological community

Answer 1

accumulation of populations of various species living close enough for potential

Question 2

what are interspecific interactions

Answer 2

takes place between specie in a community

Question 3

what are some types of interspecific interactions

Answer 3

competition, predation, herbivory, parasitism, mutualism, commensalism

Question 4

what is competition

Answer 4

when different species compete for a resource that limits survival and reproduction

Question 5

what can strong competition lead to

Answer 5

competitive exclusion

Question 6

what is competitive exclusion

Answer 6

local elimination of the inferior competitor and can lead to extinction; where animals can’t coexist

Question 7

what can competing for limited resource cause

Answer 7

evolutionary change

Question 8

what is ecological niche?

Answer 8

relationship that an organism has with the biotic and abiotic resources that it uses in its environment

Question 9

what can coexist in a community

Answer 9

similar species if there are one or more significant differences in their niches

Question 10

what is resource partitioning

Answer 10

differentiation of niches that enables similar species to coexist in a community

Question 11

what is exploitation

Answer 11

+/- interaction

one species benefits by feeding on the other species

Question 12

where is exploitation common

Answer 12

in non photosynthesis organisms

Question 13

what are some exploitative interactions

Answer 13

predation, herbivory, parasitism

Question 14

what is predation

Answer 14

-+/- interaction

one species the predator kills and eats the other which is the prey

Question 15

what are some adaptations that predators have

Answer 15

claws, fangs, or poison

Question 16

what adaptations do prey display

Answer 16

hiding, fleeing, and forming herds or schools (clumps)

- morphological and physiological defense: porcupines and skunks

Question 17

what is aposematic coloration

Answer 17

Animals with chemical defenses often exhibit

bright warning coloration

Question 18

what is cryptic coloration

Answer 18

camouflage, makes prey
difficult to see in their
environment

Question 19

what is batesian mimicry

Answer 19

Harmless individuals that resemble
members of a harmful species are
avoided by predators that have
learned not to eat the harmful ones

Question 20

what is mullerian mimicry

Answer 20

two or more

unpalatable species resemble each other

Question 21

how can predators learn to avoid unpalatbale species

Answer 21

they encounter more of

them with a similar appearance

Question 22

description of herbivory

Answer 22

• +/- interaaction
• herbivore eats plant
• harm but do not kill
• most are invertebrates

Question 23

what is the most familiar herbivore

Answer 23

large mammals (cattle, sheep, buffalo)

Question 24

what do plants do to prevent herbivores

Answer 24

produce toxic or distasteful chemicals or

mechanical defenses, such as spines or thorns

Question 25

what special adaptations do herbivores have

Answer 25

- chemical sensors that enable them to distinguish toxicity or nutritional value of plant - specialized teeth

Question 26

description of parasitism

Answer 26

- (+/– interaction -one organism, the parasite, derives nourishment from another organism, its host, which is harmed in the process

Question 27

what are endoparasites

Answer 27

live within the body of host | ex: ringworm

Question 28

what are ectoparasites

Answer 28

live on the external surface | example: head lice

Question 29

what are the types of + interactions

Answer 29

mutalism, commensalism

Question 30

description of mutualism

Answer 30

- +/+ - benefits both species - each species depends on each other

Question 31

description of commensalism

Answer 31

- +/0 | - one species is benefited and the other is neither harmed or helped

Question 32

what can positive interactions influence

Answer 32

structure of ecological communities

Question 33

what are the fundamental features of community structure

Answer 33

species diversity | and feeding relationships

Question 34

what is species diversity

Answer 34

-variety of organisms that make up the community which has two components: species richness and relative abundance

Question 35

what is species richness

Answer 35

number of | different species in the community

Question 36

what is the relative abundance

Answer 36

proportion each species represents of all individuals in the community

Question 37

what does species diversity provide

Answer 37

stability from disturbances

Question 38

characteristics of communities with higher diversity

Answer 38

- produce more biomass - more stable - able to withstand and recover from environmental stresses - more resistant to new species

Question 39

what is a trophic structure

Answer 39

the feeding relationships between organisms in a community | * key factor that affects community structure and dynamics

Question 40

what is a food chain

Answer 40

s link trophic levels | from producers to top carnivore

Question 41

what is a food web

Answer 41

group of food chains linked together | forming complex trophic interactions

Question 42

what do the arrows in a food web show

Answer 42

who eats whom

Question 43

what does phytoplanton serve as

Answer 43

food for zooplanktons (copepods and krill)

Question 44

who eats zooplankton

Answer 44

birds

Question 45

what is the energetic hypothesis

Answer 45

length is limited by inefficent energy transfer

Question 46

what is the 10% energy rule

Answer 46

10% of the energy is passed on on each level

Question 47

what are some limits on food chain length

Answer 47

carnivores tend to be larger at higher trophic levels | - large carnivores can't obtain enough food from their small prey

Question 48

why is it good to eat prey

Answer 48

they have fat which gives them energy for travelling hunting, and maintaining an optimal body temp

Question 49

which species have large impact

Answer 49

-highly abundant and have an essential role | -

Question 50

what is foundation species(dominant)

Answer 50

species that are most abundant or have a large size

Question 51

what is the hypothesis about dominant species

Answer 51

- most competitive in taking key resources like space water nutrients and light

Question 52

what are keystone species

Answer 52

strong control on a community bc of their pivotal ecological roles -

Question 53

differense between foundation and keystone species

Answer 53

keystone is not that abundant

Question 54

what is an ecosystem engineers

Answer 54

cause physical changes in | the environment that affect community structure

Question 55

why are trees considered foundations species and ecosystem engineers

Answer 55

prescense creates habitat for other species

Question 56

what is biomanipulation

Answer 56

used to restore species - organisms are controlled by what they eat - organisms controlled by what eats them

Question 57

what is the bottom up model

Answer 57

influence from lower to higher trophic levels

Question 58

top down model

Answer 58

control comes from the trophic level

Question 59

how can top down control have benefits

Answer 59

improve water quality with high abundance of algae

Question 60

lake water suffers from what

Answer 60

abundance in algae

Question 61

what does removing fish do to the water

Answer 61

improves water quality

Question 62

what is the intermediate disturbance hypothesis

Answer 62

states that moderate levels of disturbance can foster greater diversity than either high or low levels of disturbance

Question 63

what does the flood intensity graph show

Answer 63

intermediate have increased species diversity

Question 64

high levels of disturbance =

Answer 64

decreased diversity

Question 65

low levels of disturbance

Answer 65

decreased diversity, dominant species excluded less competitve species

Question 66

what is ecological succession

Answer 66

sequence of changes in | community composition following a disturbanc

Question 67

what is primary succession

Answer 67

New species begin colonizing where no soil exists (lifeless area) in a new volcanic area – Initial species : prokaryotes and protists (e.g., mosses

Question 68

what is secondary siccession

Answer 68

Occurs where soil still exists – Recolonized of an area after a major disturbance removed most but not all of the organisms – Agricultural fields that have been abandoned