Population Growth Flashcards Preview

BIO120 > Population Growth > Flashcards

Flashcards in Population Growth Deck (14)
Loading flashcards...
1

per-capita rate of increase (r)

brith rate - death rate

2

intrinsic rate of increase (r max)

rate @ which population will grow under optimal conditions
- fixed number for each speci
- max growth rate

ΔN/Δt = r max N

(ie) high birth rates
(ie) low death rates

3

exponential population growth

increase in population size when r = constant
- density independent
- cannot continue indefinitely

4

density independent

(population ecology) any characteristic that does not vary w/ population density
- abiotic

5

density dependent

(population ecology) any characteristic that varies depending on population
- biotic

6

carrying capacity (K)

max. population size of a certain species that a given habitat can support
- density dependent
- changes yearly, depends on conditions

7

logistic population growth

density-dependent decrease in growth rate as population size approaches carrying capacity
- density dependent
- forces curve to level off

ΔN/Δt = r max N[(K-N)/K]

8

N

number of individuals in population

9

r variations

(1) birth > death = +r
(2) birth < death = -r
(3) birth = death -> static

10

+r

growing population

11

-r

declining population

12

r max variations

(1) diff btwn species
(2) same w/in species
(3) diff. btwn similar population in diff. time or space

13

why exponential growth happens?

(1) few individuals find a new population & habitat
(2) small population survived natural disaster & are recovering

13

K is dependent on

(1) food
(2) space
(3) water
(4) soil quality
(5) resting & nesting sites
(6) weather/climate