Populations And Sustainability 2

Question 1

Population growth curve

Answer 1

Phase 1 - period of slow growth
Phase 2 - rapid growth
Phase 3 - stable state north and death rates are relatively equal

Question 2

Limiting factors

Answer 2

Prevent further growth of a population
- abiotic factors - temp light pH availability of water
- biotic factors - predators disease competition

Question 3

Migration

Answer 3

Immigration- movement of indiv into a particular area increased pop size
Emigration- movement of individuals away from a particular are decreases pop size

Question 4

Density dependent factors

Answer 4

these limiting factors increase with the size of the population and limit growth as population size increases

Question 5

Competition types

Answer 5

Interspecific
Intraspecific

Question 6

Interspecific

Answer 6

Competition between different species for the same resource
Less adapted species becomes outcompetes and numbers decline

Question 7

Intraspecific competition

Answer 7

Same species compete for same resource
Greater availability of resource the population increase can be supported

Question 8

Intraspecific competition stages

Answer 8

Stage 1- resource is plentiful all organisms reproduce once population
Stage 2 - resources limited due to more numbers populations decrease
Stage 3 - less competition population increases

Question 9

Predator prey population relationship

Answer 9

Stage 1- increase in prey pop more food for predators (increase pop of pred.)
Stage 2- increased predator population eats more prey decreasing prey pop
Stage 3- Intraspecific competition occurs in predators decrease predator pop
Stage 4- reduced predator more prey reproduce cycle begins again

Question 10

Conservation

Answer 10

Maintenance of biodiversity through human action or management
Natural resources used without running out - sustainable development

Question 11

Reclamation

Answer 11

Restoring ecosystems that have been damaged or destroyed eg by floods or building development

Question 12

Preservation

Answer 12

Protection of an area by restricting/ banning human interference

Question 13

Importance of conservation

Answer 13

Economic- provide resources humans need and to provide an income
Social- enjoy the natural beauty of wild ecosystems
Ethical - all organisms right to exist and most play important role in ecosystem

Question 14

Sustainable resource

Answer 14

A renewable resource that is economically exploited in such a way that it will not run out

Question 15

Aims of sustainability

Answer 15

Preserve environment
Ensure resources are available for future
Allow humans in all society to live comfortably
Enable less economical developed countries to develop exploiting Nat resources

Question 16

Small scale timber production

Answer 16

Coppicing- trunk is cut close to the ground and new shoots form form cut surface and mature
Rotational coppicing takes place - maintaining biodiv as trees never grow enough to block light so succession doesn’t occur

Question 17

Large scale timber production

Answer 17

To ensure sustainability
Practise selective cutting - biggest trees only
Replace trees
Plant optimal distance apart to reduce competition
Manage pests to max yield
Ensure areas of forest remain for people who live there

Question 18

Disadvantage of large scale timber

Answer 18

Habitats destroyed
Soil minerals reduced and susceptible to erosion
Trees are important in carbon and nitrogen cycles

Question 19

Sustainable fishing

Answer 19

Overfishing has led to a decline in many populations and are unable to regenerate
CFP in EU provide limits on what species of fish allowed in specific area
Specific mesh used - young fish escape
Only at certain times
Fish farming