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Geography - population and the environment > Population ecology > Flashcards

Flashcards in Population ecology Deck (26):
1

what is ecology?

the study of interactions among organisms and their environment

2

what is population?

all the individuals of a species that live together

3

what are the 3 key features of a population?

size
density
dispersion

4

what is size?

the number of individuals in an area

5

what is density?

the measurement of population per unit area

6

what is dispersion?

the spread of population can be clustered, random and uniform

7

what is biotic potential?

the natural reproductive potential of the species

8

what is environmental resistance?

a term used in population ecology to explain mortality rates controlled by environmental factors that prevent survival

9

what is a density independent environmental limiting factor ?

increase death rate whatever the population size

10

what is a density dependent

food supply /disease will become more prevalent limiting growth as the population increases

11

what has human population been like for the past 200 years?

been in a long phase of exponential growth for the past 200 years

12

what is the optimum population?

ideal balance between population and resources

13

what is overpopulation?

too many people in an area relative to the available resources

14

what is underpopulation?

too few people to use resources efficiently for a given level of technology

15

what is the biosphere?

the biological components of the Earth's systems

16

what is the carrying capacity?

the maximum population size that an area can sustain indefininetly

17

what is the ecological footprint?

a measure of the demand placed by humans on Earth's natural ecosystems

18

what is an overshoot?

refers to a point when the population and its associated consumption resources exceeds the long term carrying capacity

19

what is the total productivity bio-capacity?

all the food water and energu resources produced by the earths natural systems in order to sustain us

20

carrying capacity-professor william rees

-flexible depending on average lifestyle
-varying levels of consumption of resources
-earth may support 10 bil at modest level of consumption but we will have a lower carrying capacity if we waste resources and live the life of HICS

21

Rees calculation of carrying capacity

measure the total productivity bio capacity of earth by dividing it by total population

22

implications of carrying capacity

-concept of carrying capacity introduces a limit to population growth

23

implications of a growing ecological footprint

climate change
more land used for settlement and industry
degradation of natural ecosystems
increased threat of species extinction
depletion of fish stocks
overgrazing

24

what is the case study used for population growth?

Easter island

25

where did it all go wrong ... Easter island

easter island is a reminder that there are finite limits on our environment

26

as a global society...

if we continue to use the environment in an unsustainable way then we will have to learn to live differently and live with less