2.1 populations and resources - msholau.weebly.com · 2.1 populations and resources p.49...

2.1 POPULATIONS AND RESOURCES

2.1 POPULATIONS AND RESOURCES P.49

population:

all the individuals of a species

occupy same location at the same time

can successfully reproduce

EXPONENTIAL GROWTH P.50

EXPONENTIAL GROWTH P.50 accelerative growth

produces a J-shaped curve

only happens under certain conditions and for a short

time

eg. new habitat, pressure removed, re-introduced

species

cannot be sustained in nature because no unlimited

supply

limiting factors:

limit growth, distribution or amount of population

eg food, temperature, pH

CARRYING CAPACITY P.51

CARRYING CAPACITY P.51

size of a population that can be supported

indefinitely by the available resources and

services of an ecosystem

at equilibrium

CARRYING CAPACITY P.51

HUMAN ACTIVITIES AND CARRYING CAPACITY

P.52

HUMAN ACTIVITIES AND CARRYING CAPACITY

P.52

human change ecosystems change carrying

capacities

urban sprawl:

growth of relatively low-density development on the

edges of urban areas

THE STORY OF THE REDSIDE DACE P.53

THE STORY OF THE REDSIDE DACE P.53

more urban sprawl

less stream-side shade trees, more run-off

carrying capacity ↓

population ↓

INTENSIFICATION P. 54

INTENSIFICATION P. 54

policy to reduce urban sprawl

new development occurs within a city