Ecology Exam 2 낱말 카드 | Quizlet

exponential growth

population grows by increasingly faster rate continuously

geometric growth

population grows by increasingly faster rate at specific intervals

population

a group of organisms of the same species occupying a particular space at a particular time

biological species

groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups

(birth rate) + (immigration) - (mortality) - (emigration)

population change

population density

individuals per area

population dispersion

spatial arrangement of individuals relative to one another

age structure

number of males and females of each age in a population

uniform dispersion

The same all the way through; consistent

random dispersion

irregular

clumped dispersion

individuals are highly concentrated in some regions and more sparse in others

prereproductive

before reproductive age

reproductive

at reproductive age

postreproductive

after the reproductive age

N

population size

dn/dt = rN

exponential population growth equation

dN/dt

instantaneous rate of change in population size

r

instantaneous per capita rate of growth, or intrinsic rate of increase

(Nt) = (N0) e^(rt)

integration of rN

N0

the population size at time 0

Nt

the population size at time t

e

Euler's number

t

time

λ

finite rate of increase from one step to the next

(Nt) = (N0)(λ^t)

Geometric growth equation

x

age in years

nx

number of individuals in x age

lx

proportion surviving at start of age interval x

dx

number dying within age interval (x) to (x + 1)

qx

mortality rate

(lx) = (nx)/(n0)

lx formula

(dx) = (nx)-(nx+1)

dx formula

(qx) = (dx)/(nx)

qx formula

(sx) = 1 - (qx)

sx formula

sx

age specific survival rate

bx

age specific birth rate

(R0) = (lx)(bx)

net reproductive rate formula

type I survivorship curve

survivorship is high in youth but decreases over time dramatically. This is seen in animals with extended parental care.

mammals

has type I survivorship curve

type II survivorship curve

survivorship decreases steadily

birds, rodents, reptiles, perennial plants

has type II survivorship curve

type III survivorship curve

survivorship plummets early and stays steady throughout the rest of life

insects, marine invertebrates, fish and forest trees

has type III survivorship curve

population projection

age specific survivorship and birth rates are used to project changes in population size into the future

λ stabilizes over time

what happens to λ over time

λ = (Nt+1)/(Nt)

λ

age distribution stabilizes over time

what happens to age distribution over time

life cycle diagram

An illustration showing all stages of a life cycle.

Pi

the probability than an individual in age class i will survive to age class i + 1

Fi

fertility of each age class i

fertility

the number of young produced per female

Gi

the probability that each stage i will progress to the next stage in a stage-structured model

Leslie matrix

a matrix in which the columns represent age class at time t and the rows represents age class at time t + 1

Lefkovitch matrix

similar to a Leslie matrix but for a stage-structured model

eigen analysis

breaks down a linear matrix into stable lambda, age distribution, and the sensitivity and elasticity of each vital rate in the matrix as well as the reproductive value and damping ratio

sensitivity value

indicate how a small absolute change in Fi or Pi value will affect λ when everything else is held constant

elasticity value

indicate how a proportional change in an Fi and Pi value will effect λ

natural selection favors individuals who maximize lifetime fitness

which life history traits are favored

lifetime fitness

the number of offspring produced that survive to reproduce

life history

the pattern of allocation throughout an organisms life to growth, maintenance and reproduction

trade-off

an inevitable compromise between one trait and another that arises

many small offspring vs few large offspring

size of offspring and number of offspring tradeoff

early maturity and high adult mortality vs late maturity and low adult mortality

age of maturity and adult mortality rate tradeoff

semelparous

reproduce once and die

low growth with many offspring vs high growth with few offspring

growth of adult and egg number tradeoff

low growth and more offspring

offspring number and growth in high risk of mortality environment

high growth and less offspring

offspring number and growth in low risk of mortality environment

often limiting

resource availability in stable environment

rarely limiting

resource availability in ephemeral environment

ephermeral

very variable

high

degree of competition in stable environment

low

degree of competition in ephemeral environment

density-dependent factors

main source of mortality in stable environment

density-independent factors

main source of mortality in ephemeral environment

low

population size in ephemeral environment

high

population size in stable environment

K-strategist

organism in stable environment

r-strategist

organism in ephemeral environment

long lifespan

K-strategist lifespan

slow development

K-strategist development time

large body size

K-strategist body size

low number of offspring

K-strategist number of offspring

late maturity

K-strategist age of maturity

high parental care

K-strategist parental care

short lifespan

r-strategist lifespan

fast development

r-strategist development time

small body size

r-strategist body size

high number of offspring

r-strategist number of offspring

early maturity

r-strategist maturity age

low parental care

r-strategist parental care

population increasing

λ < 1 and r < 0

population decreasing

λ < 1 and r < 0

population staying same size

λ = 1 and r = 0

unlimited resources and constant environment

assumptions of exponential and geometric population growth

logistic growth

growth pattern in which a population's growth rate slows or stops following a period of exponential growth

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

logistic population growth formula

K

carrying capacity

K/2

the point in logistic growth when r is at a maximum

dN/dt = rN

when N is small

dN/dt = 0

when N is close to K