population ecology - exam 4

Question 1

population ecology

Answer 1

dynamics of species populations & how they interact w/ the environment

Question 2

population

Answer 2

group of individuals of the same species that live in the same area

Question 3

INTRAspecific interactions

Answer 3

interactions between members of the SAME species

same resources
same environmental factors

Question 4

density

Answer 4

number of individuals per area

mass in a given volume

Question 5

what is density limited by

Answer 5

resources

limiting agents - disease parasites, predators

Question 6

dispersion

Answer 6

local densities differ – contrasting patterns of dispersion

Question 7

clumped dispersion

Answer 7

individuals aggregated in patches

Question 8

what does clumped dispersion result from

Answer 8

uneven distribution of resources

mating or social behaviors (hunting together)

Question 9

uniform dispersion

Answer 9

individuals evenly spaced

Question 10

what does uniform dispersion result from

Answer 10

aggressive interactions

severe competition for resources

Question 11

random dispersion

Answer 11

no pattern seen

Question 12

what does random dispersion result from

Answer 12

no special forces acting on spatial distribution of individuals in population

homogenous environment

Question 13

population structure

Answer 13

make up of individuals in the population

sex ratio
age structure

Question 14

sex ratio

Answer 14

males: #females

primary = conception
secondary = birth/hatching
tertiary = later stage of life

ratio can become more skewed

Question 15

reproduction related stresses

Answer 15

reason for skewed 3rd sex ratio

ex - females not fighting, nesting females more vulnerable

Question 16

dispersal

Answer 16

reason for skewed 3rd sex ratio

(leaving the nest) increases risk of predation in dispersing sex

Question 17

intraspecific competition

Answer 17

reason for skewed 3rd sex ratio

dominance status
energetic requirements

Question 18

intraspecific competition examples

Answer 18

migrating birds - males go first & take prime spots, females have to go farther

elk - males are bigger & more susceptible to food shortages & sink into snow

Question 19

age structure

Answer 19

% of individuals in different ages or age groups in the population

can be used to predict future population growth/decline

Question 20

population rates

Answer 20

growth & decline

survival patterns

Question 21

fecundity

Answer 21

of offspring/time (per female)

generally limited by # of gametes (eggs)

Question 22

survivorship

Answer 22

tracks changes in # of individuals in a cohort over time

Question 23

type I survivorship curve

Answer 23

late loss

most deaths occur at limit of biological lifespan

humans, annual plants, sheep, elephants

Question 24

type II survivorship curve

Answer 24

constant loss

individuals in all age categories have fairly uniform death rates

rodents, perennial plants, song birds

Question 25

type III survivorship curve

Answer 25

early loss

death is prevalent for younger members & declines w/ age

sea turtles, trees, fish, internal parasites

Question 26

life history traits

Answer 26

traits that affect an organism’s schedule of reproduction & survival

r & K strategists

Question 27

r-strategist

Answer 27

many offspring

small offspring

no parental care

grow fast

reproduce young

type III
exponential growth rate
pyramid shaped age structure

Question 28

K-strategist

Answer 28

few offspring

big offspring

lots of parental care

slow growth

delayed reproduction

type I
logistic population growth
columnar age structure

Question 29

exponential growth

Answer 29

rate of population expansion under ideal conditions

abundant food
free to reproduce @ physiological capacity

Question 30

exponential growth equation

Answer 30

dN/dt = rN

r = rate of increase
larger r = faster growth increase

Question 31

r is small if…

Answer 31

high death rate
low birth rate

individuals not fecund or fertile
sex ratio skewed towards males
long generation time

Question 32

density dependent pop limiting factors

Answer 32

food
space
disease
predation
territoriality
toxic wastes

Question 33

density independent pop limiting factors

Answer 33

weather
disease

Question 34

abiotic factors

Answer 34

not living

natural disasters
temp
soil
water

Question 35

carrying capacity

Answer 35

K

maximum pop size that a particular environment can sustain

varies over space & time – changing w/ resources

Question 36

logistic growth

Answer 36

idealized pop growth that is slowed pop limiting factors as pop size increases

Question 37

logistic growth equation

Answer 37

dN/dt = rN(1-N/K)