chapter 40: population ecology and the distribution of organisms Flashcards Preview

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Flashcards in chapter 40: population ecology and the distribution of organisms Deck (50)
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1
Q

what is ecology?

A

the scientific study of the interactions between organisms and the environment. these interactions determine organisms distribution and abundance.

2
Q

what is climate?

A

the long term prevailing weather conditions in an area constitute its climate

3
Q

what are the four major abiotic components of climate?

A

temperature, precipitation, sunlight, and wind

4
Q

what are abiotic factors?

A

abiotic factors are the non-living chemical and physical attributes of the environment

5
Q

what are biotic factors?

A

biotic factors are the other organisms that make up the living component of the environment

6
Q

what are global climate patterns determined by?

A

they are determined largely by solar energy and the planet’s movement in space

7
Q

what does the warming effect of the sun cause?

A

the warming effect of the sun causes temperature variations, which drive evaporation and circulation of air and water. this causes latitudinal variations in climate.

8
Q

what are species distributions the result of?

A

ecological and evolutionary interactions through time.

9
Q

what biotic factors affect the distribution of organisms?

A

1) predation
2) herbivory
3) mutualism
4) parasitism
5) competition

10
Q

what is predation?

A

the preying of one animal on others

11
Q

what is herbivory?

A

the consumption of plant material by animals

12
Q

what abiotic factors affect the distribution of organisms?

A

1) temperature
2) water and oxygen
3) salinity
4) sunlight
5) rocks and soil
6) physical structure
7) pH
8) mineral composition

13
Q

what is salinity?

A

amount of salt dissolved in a body of water

14
Q

what is population ecology?

A

explores how biotic and abiotic factors influence density, distribution, and size populations

15
Q

what is a population?

A

a group of individuals of a single species living in the same general are. they are described by their boundaries and size.

16
Q

what is dispersal?

A

the movement of individuals away from centres of high population density or from their area of origin. dispersal contributes to the global distribution of organisms.

17
Q

what is density?

A

the number of individuals per unit area or volume

18
Q

does canada have a low or high density?

A

low density

19
Q

what is despersion?

A

the pattern of spacing among individuals within the boundaries of the population

20
Q

what are the 3 types of dispersion?

A

1) clumped - for resources
2) uniform - spread out evenly in a specific order
3) random - unlimited resources

21
Q

what is demography?

A

the study of the vital statistics of a population and how they change over time

22
Q

what is the change in population size formula?

A

change in population size = births + immigrants entering population - deaths + emigrants leaving population

23
Q

what is the population growth rate formula?

A

delta N / delta T = B - D

24
Q

what is the per capita growth rate formula?

A

cgr. = delta N/ N or N(final)-N(final)/ N(initial)

25
Q

what is exponential population growth?

A

the population increase under idealized conditions

26
Q

what is r max?

A

under idealized conditions, the rate of increase at its maximum is called r max

27
Q

what is the equation of exponential population growth?

A

dN/ dT = rmax N

28
Q

what type of curve does exponential population result in?

A

J shaped curve. it characterizes populations in new environments or rebounding populations

29
Q

what does lag time in a J-shaped curve graph show?

A

shows that exponential growth is coming. it is seen in populations with no limitations on resources. it is not sustainable, eventually it levels off.

30
Q

what is carrying capacity (K)?

A

the max. population size the environment can support. it varies with the abundance of limiting resources

31
Q

what is the logistic population growth model?

A

the per capita rate of increase declines as carrying capacity is reached. it starts with the exponential model and adds an expression that reduces the per capita rate of increase as N approaches K

32
Q

what type of curve does the logistic population growth model give?

A

sigmoid (s-shaped) curve

33
Q

what ends up having an s-shaped curve?

A

everything - shows limitations of an area

34
Q

what is a life history?

A

an organism’s life history comprises the traits that affect its schedule of reproduction and survival

35
Q

what does life history determine?

A

biotic potential (r)

36
Q

what is biotic potential?

A

how quickly an organism could produce if there was no limits on it

37
Q

what is K-selection?

A

selects for life history traits that are sensitive to population density

38
Q

what is R-selection?

A

selects for life and history traits that maximize reproduction

39
Q

are humans K or R selected species?

A

K selected

40
Q

what happens to birth rate and death rate in density independent populations?

A

birth and death rates do not change with population density

41
Q

what happens to birth and death rate in density dependent populations?

A

birth rates fall and death rates rise with population density

42
Q

what is competition of resources?

A

occurs in crowded populations; increasing population density intensifies competition for resources and results in lower birth rates

43
Q

what is toxic wastes?

A

produced by a population can accumulate in the environment, contributing to density-dependent regulation of population size. accumulation decreases population size.

44
Q

what is predation?

A

predation may increase with increasing population size due to predator preference for abundant prey species.

45
Q

what is territoriality?

A

territoriality can limit population density when space becomes a limited resource.

46
Q

what is disease in relation to population size?

A

disease transmission rates may increase with increasing population density.

47
Q

what are intrinsic factors?

A

physiological factors (ex. hormone changes) appear to regulate population size

48
Q

what is population dynamics?

A

the study of population dynamics focuses on the complex interactions between biotic and abiotic factors that cause variation in population size.

49
Q

what are bottom up factors?

A

Bottom up factors are pressures that limit the availability of resources to lower trophic levels (e.g. producers) A lack of resources at lower trophic levels suppresses the abundance of organisms at higher trophic levels.

50
Q

what are top down factors?

A

Top down factors are pressures applied by a higher trophic level to control the population dynamics of the ecosystem. The top predator either suppresses the abundance of its prey or alters its behaviour to limit its rate of population growth.