Populations And Sustainability

Question 1

Define carrying capacity

Answer 1

Max populations size that can be maintained in a habitat over a period of time

Question 2

Describe a K-strategist curve

Answer 2

1) lag phase= slow growth, few organisms, acclimatising to habitat, rate of reproduction low

2) log phase= rapid growth, resources are plentiful and conditions favourable, rapid population increase
Exponential growth

3) stationary phase= a stable state population size, reached carrying capacity, habitat cannot support a larger population
May fluctuate

Question 3

What are r-strategists

Answer 3

Boom or bust, extremely high reproductive rate and population growth rate before limiting factor take effect.

Small short lived species (pioneer)

Similar to stationary phase except there is a death phase after

Question 4

Define limiting factors

Answer 4

Factor that prevents further growth of a population and in some cases cause it to decline

Question 5

Name 3 abiotic factors

Answer 5

Temperature
pH
Light intensity

Question 6

Name 3 biotic factors

Answer 6

Competition
Predation
Disease

Question 7

Define immigration

Answer 7

Movement of individual organisms into a particular area

Question 8

Define emigration

Answer 8

Movement of individual organisms away from a particular area

Question 9

How can an introduced species affect other species living in the area

Answer 9

They might be predators
They might stop birds breeding and that reduces their offspring
Means there are less new breeders for the next year

Question 10

How could a species introduced to an island dramatically increase in number after introduction

Answer 10

Plenty of food and space
There is no predators
Fill a vacant niche
Cannot emigrate

Question 11

What are density independent factors

Answer 11

Affect populations of all sizes in the same way, examples are natural disasters and fires

Question 12

What is competition

Answer 12

When organisms compete for limited resources like: light, mates, food, water, minerals and space

Question 13

What are the two types of competition

Answer 13

Infraspecific

Interspecific

Question 14

What is interspecific competition

Answer 14

Competition between organisms of different species 😁

Question 15

What is interspecific competition

Answer 15

Competition between organisms of the same species

Question 16

Describe interspecific competition

Answer 16

There will be less food and less energy for growth and reproduction

Question 17

What is competitive exclusion principle

Give an example

Answer 17

Two species are competing for the same food source and the one that uses the resources more effectively will ultimately eliminate the offer

Red and grey squirrels, red squirrel are limited in what they can eat, grey squirrels can eat loads but outcompete the reds by eating all there limited food

Question 18

Explain the exponential growth in a K strategist curve

Answer 18

Resources are plentiful so population increases in size

Question 19

Describe the predator prey model

Answer 19

Predators eat prey
Prey population decreases 
Predators compete for limited prey
Predator population decreases 
Fewer prey eaten 
Prey population increases 
More food for predators so population increases

Question 20

How is the predator prey cycle different in the lab rather than the field

Answer 20

The curve in the field has fewer limiting factors

No studies have been done in more diverse environment

Question 21

Summarise the effect predators may have on the population size of prey

Answer 21

Prey numbers rise and fall- oscillate

Predators help to keep the prey numbers stable
Predation is density- dependent

Question 22

What are density dependent factors

Answer 22

Factors are dependent on population size

Question 23

Define conservation

Answer 23

Management of ecosystems sustainably to protect biodiversity

Occurs through, maintaining diversity between species, maintaining habitats and genetic diversity

Question 24

Define reclamation

Answer 24

Process of restoring ecosystems that have been destroyed

Question 25

Define preservation

Answer 25

Protecting areas of land unused by humans, examples include nature reservations and marine conservation sites

Question 26

What are two economic reasons for conservation

Answer 26

Eco-tourism= provides money and jobs

New drugs

Question 27

Two ecological reasons for conservation

Answer 27

• taking one organism out of the food web affects many others
• photosynthesis regulates climate

Question 28

Two ethical reasons for conservation

Answer 28

All organisms have the right to life

Human responsibility to provide for future generations

Question 29

Two social reasons for conservation

Answer 29

• environments allow walking, cycling, climbing - good for health
• natural environments are creative environments

Question 30

Why is it important that we conserve the rainforest (3)

Answer 30

• preserve biodiversity
• ecotourism
• potential medicine

Question 31

What is a biological resource

Answer 31

Made by living organisms

Made into products for use by human beings

Question 32

Define sustainable resource

Answer 32

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

Question 33

What is the purpose of sustainability (3)

Answer 33

• preserving the environment
• ensuring resources are available for future generations
• allow humans in all societies to live comfortably

Question 34

How is sustainable management acheived (3)

Answer 34

1) economically viable quantities of timber can be harvested year on year
2) government grants for sustainable management schemes
3) planting to ensure sustainable harvest rate

Question 35

Why do we use sustainable management

Answer 35

To maintain biodiversity and to allow timber companies to have a secure and sustainable supply of wood

Prevents disruption to nesting sites and prevents soil erosion

Question 36

Name and explain an example of small scale timber production

Answer 36

Coppicing- deciduous trees:

• the tree is cut close to base in winter
• the following spring shoots rapidly regrow from stool (base)
• 7-20yrs later coppice ready for next harvest

Question 37

Why may pollarding be used instead of coppicing

Answer 37

When deer species are high

-the trunk gets cut higher so the deer cannot reach the new shoots

Question 38

Describe rotational coppicing

Answer 38

Divide the wood into sections
Cut a different section each year
Larger trees are not cut down but used for larger timber
Rotational coppicing is good for biodiversity
Different light levels to different habitats👍

Question 39

Name a negative example of large scale Timber production

Answer 39

Clear-felling:
The removal of all trees from an area chosen for harvesting (logging)
❌reduces soil mineral levels
❌encourages soil erosion

Question 40

Describe large scale timber production on a sustainable level

Answer 40

1- selective cuttting- removing only the largest trees
2- replace through replanting
3-plant these trees an optimal distance apart to reduce competition
4-manage pests and pathogens
5-ensures areas of the forest remain for indigenous people

Question 41

What is the planting strategy in sustainable forests

Answer 41

Trees aren’t planted too close together to reduce competition- water, sunlight

Fallen trees are left to rot to create habitat

Question 42

What is selective cutting

Answer 42

Removing only the largest trees

Replace the trees through replanting (put rides in)

Question 43

Define ecology

Answer 43

The study of interactions of organisms and their environment

Question 44

Define ecosystem

Answer 44

A physical area that includes all the organisms and their interactions with the physical environment

Question 45

Define sustainability

Answer 45

How biological systems remain diverse and productive over time

Question 46

Explain sustainable fishing

Answer 46

International agreements about the number of fish to be caught

Quotas provide limits on the number of fish caught in a given area

Use nets with different mesh sizes- specific types of fish only are caught

Fish only at certain times of the year- protects breeding season

-fish farming

Question 47

No que cards on examples like Masai Mara

Answer 47

Soz