Chapter 27 - Human Impact

Question 1

Example of how humans lead to major changes in communities

Answer 1

increasing CO2 levels due to industrial, agricultural and domestic needs –> changes in weather patterns and increased sea levels –> effect on populations

Question 2

EXAMPLE OF EXTINCTION (learn well!)

Answer 2

Dodo bird
calvaria major tree in mauritius
hard seed must pass through digestive tract
now risk of exinction

= ALL LIFE IS INTERCONNECTED

Question 3

to save a species you must:

Answer 3

save its habitat

Question 4

two levels of conservation:

Answer 4

ensure area is large enough to support 50 of the largest carnivores in habitat
should be secure enough to support 500 indivs.

Question 5

Population expansion for k and r selected + humans

Answer 5

K selected - no.s fluctuate = exponential growth, habitats carrying capacity
r selected - until food supply is exhausted

humans can manipulate their environment = exponential growth
reasons: medicine, technology, clean water etc.

Question 6

what is the biosphere?

Answer 6

surface of the earth where living things are found

Question 7

what are human demands on the biosphere?

Answer 7

space: to live, farm and mine
ocean: over fishing of some species
soil degradation: farming, mining, run-off and deforestation –> lead to lower nutrient levels –> species including humans are affected