ecosystem dynamics - population dynamics

Question 1

population dynamics

Answer 1

ecological interactions that lead to fluctuations in population size. refers to how populations of a species change in size & structure

Question 2

carrying capacity

Answer 2

the maximum population size of the species that the environment can sustain

Question 3

size

Answer 3

total area a population can be found in

Question 4

density

Answer 4

number of species found per unit

Question 5

population abundance

Answer 5

relative representation of a species in a particular ecosystem, measured via size or density

Question 6

stable population

Answer 6

relatively predictable ecosystem, larger, longer-lived species outcompete the smaller, faster-growing species. such species have a steadier population growth pattern, and can exist in numbers closer to the carrying capacity of the environment

Question 7

unstable population

Answer 7

unpredictable ecosystems, opportunistic species move in and colonise quickly. colonising populations show a pattern of rapid increase where the maximum reproductive potential of the species is met, then decline (or crash) in numbers

Question 8

k-selected species

Answer 8

longer life cycle, relatively large size, parental care (e.g. kangaroos, elephants, whales, gorillas, oak trees & eucalypts)

Question 9

r-selected species

Answer 9

short life cycle, relatively small size, lack of parental care (e.g. frogs, rats, weeds, swarming insects such as locusts)

Question 10

birth rate / death rate

Answer 10

number of birthdays/deaths per thousand of a population

Question 11

immigration / emigration

Answer 11

an increase/decrease to the population due to migration of individuals in/out of the habitat

Question 12

population growth rate

Answer 12

(r)=(b+i)-(d+e)

Question 13

distribution

Answer 13

exactly where in the physical space members of different species are found. patterns include random, uniform (continuous) and clumped (group)

Question 14

limited resources

Answer 14

availability of water, food, sunlight, shelter or things such as predation/disease

Question 15

equilibrium population

Answer 15

the population the ecosystem can support, represented by the population growth curves

Question 16

lag

Answer 16

slow growth because there are only a few reproductive individuals who are not yet widely distributed

Question 17

exponential growth

Answer 17

a rapid increase in population size as birth rate greatly exceeds death rate. mortality is low due to abundant resources

Question 18

transitional

Answer 18

population rate decelerates. resources eventually become limited, which leads to competition for survival. birth rates start to fall and death rates begin to rise

Question 19

plateau

Answer 19

overall birth rate equals death rate. the population has reached carrying capacity. the population size at this point will not be constant but it will fluctuate around the carrying capacity

Question 20

density dependent factors

Answer 20

effect the population depending on the density, greater the density the more individuals die or fail to reproduce. most are biotic, and include predation, interspecific, and intraspecific competition, accumulation of waste, and disease (e.g. parasites)

Question 21

density independent factors

Answer 21

affect individuals of the population regardless of density, giving all an equal chance of survival. include severe weather conditions, (e.g. fire, tsunami) or physical factors (acidity, temperature)

Question 22

abundance

Answer 22

number of species in a population