6.6 Populations and Sustainability

Question 1

What is the carrying capacity of a population?

Answer 1

The maximum population size that can be maintained over a period of time.

Question 2

What defines the carrying capacity of a population?

Answer 2

The limiting factors of the habitat

Question 3

What are the two types of reproductive strategies amongst species?

Answer 3

• r

- k

Question 4

Which types of strategists often experience ‘boom or bust’ population growth.

Answer 4

r Strategists

Question 5

Describe features of r Strategists

Answer 5

• smaller, weaker and shorter lifespans
• produce more offspring
• take less care of their offspring
• often exceed the carrying capacity
• shorter time for development and reproductive maturity
• usually prey

Question 6

Describe features of k Strategists

Answer 6

• larger, stronger and longer lifespans
• produce less offspring
• take more care of their offspring
• population growth is more stable
• longer time for development and reproductive maturity
• usually predators

Question 7

What is interspecific competition?

Answer 7

Competition between members of different species

Question 8

What is intraspecific competition?

Answer 8

Competition between members the same species

Question 9

Which type of competition will decrease population size and is fundamental to natural selection?

Answer 9

Intraspecific competition

Question 10

When can interspecific competition happen?

Answer 10

When species have overlapping niches

Question 11

What is a niche

Answer 11

An organisms specific role in the ecosystem

Question 12

What affects the extent of interspecific competition

Answer 12

The extent of the overlap between the two species niches

Question 13

Describe the competitive exclusion principle

Answer 13

When 2 species can not occupy the exact same niche in an ecosystem as one species will either adapt or go extinct due to interspecific competition

Question 14

Describe preservation

Answer 14

The maintenance of habitats and ecosystems in their present condition to minimise human impact and keep them as they are to prevent any future change

Question 15

Describe conservation

Answer 15

The active protection and management of an ecosystem so the natural resources can be used without running out and be available for future generations by maintaining biodiversity.

Question 16

Which is a dynamic process, preservation or conservation?

Answer 16

Conservation

Question 17

What is the difference between preservation and conservation?

Answer 17

Conservation is an active process to manage the ecosystem in order to improve biodiversity and protect resources however preservation aims to maintain the habitat as it is and minimise any future human impact.

Question 18

What are the categories of benefits from conservation?

Answer 18

• economic (trade of resources and ecotourism)
• social (benefits lifestyle and pleasure of humans)
• ethical (moral duty to protect ecosystems and organisms)
• ecological (to maintain biodiversity)

Question 19

Give 3 economic reasons for conservation

Answer 19

• species provide valuable food sources
• ecosystems provide opportunities for ecotourism
• ecosystems provide resources that can be traded

Question 20

Describe the social reasons for conservation

Answer 20

Ecosystems are attractive and enjoyed by humans which can boost their wellbeing and health

Question 21

Describe ethical reasons for conservation

Answer 21

All organisms have a right to survival and humans have an ethical responsibility to conserve especially when humans are the cause.

Question 22

Give 4 ecological reasons for conservation

Answer 22

• can help to prevent further climate change
• preserve keystone species
• prevents disruption of food chains
• maintains genetic diversity which reduces disease susceptibility and is a useful resource in agriculture

Question 23

Describe the difference between density dependent and density independent limiting factors

Answer 23

Density independent limiting factors act as strongly regardless of the population size whereas density dependent limiting factors increase in magnitude as the population size increases

Question 24

Give an example of a density independent limiting factor

Answer 24

Temperature

Question 25

Give an example of a density dependent limiting factor

Answer 25

Food

Question 26

What mechanism occurs in the relationship between predators and prey in an ecosystem

Answer 26

Negative Feedback

Question 27

Describe the stages in a predator prey relationship

Answer 27

- As the predator population increases, more prey are eaten - There is therefore less food for the predator so it becomes a limiting factor in population growth - Fewer predators survive and their population decreases - With less predators, fewer prey are being eaten so their population size increases - With more prey available, the predator population size then gets bigger again and the cycle continues

Question 28

Describe how in the stationary phase of growth, intraspecific competition keeps population size relatively stable

Answer 28

If the population size increases, then intraspecific competition will increase and population size will fall and vice versa

Question 29

Give 2 limits of the predator prey relationship model

Answer 29

- In a real ecosystem, there is a more complex food chain where the predator eats many different prey - In a real ecosystem, there are other limiting factors to a population

Question 30

What is allelopathy

Answer 30

Competition between plants through the release of chemicals

Question 31

Define sustainability

Answer 31

The use of resources so that they can be maintained for future generations

Question 32

Describe coppicing

Answer 32

When the stem of a deciduous tree is cut close to the ground so that new shoots can grow from the surface

Question 33

Describe rotational coppicing

Answer 33

When a woodland is divided into sections and each year a different section is coppiced. In each section, some trees are left to grow larger before being harvested. These are called standards

Question 34

Explain why rotational coppicing is good for biodiversity

Answer 34

Different sections of the woodlands will provide different habitats which will increase species biodiversity. Additionally it prevents the succession of the woodland to become too dense and block out sunlight for species

Question 35

What are 2 detriments of clear felling

Answer 35

- completely destroys habitats | - reduces soil mineral levels and causes soil erosion

Question 36

Explain why clear felling damages soil

Answer 36

There are no trees to take in water so excess water (from rain) causes soil to be washed off. This depletes soil mineral levels

Question 37

What is the modern alternative to clear felling?

Answer 37

Selective felling

Question 38

What are the principles of modern large scale timber production

Answer 38

- any tree harvested is replaced - the forrest maintains it's ecological function and diversity - trees are positioned at optimal distances away from each other - pests and pathogens are controlled

Question 39

What is an alternative to fishing

Answer 39

Aquaculture

Question 40

What are the marine stewardship councils principles for sustainable fishing

Answer 40

- avoid overfishing and keep fish populations close to carrying capacity - the structure, function and biodiversity of the systems must remain

Question 41

What was implemented by the Nepalese government and the WWF

Answer 41

The Terai Arc Project

Question 42

Give methods of conservation from the Terai Arc Project

Answer 42

- community forestry initiatives gave locals rights to exploit the forest but responsibilities to look after it - created forest corridors between national parks (helping survival of tigers) - counteracting poachers and illegal felling

Question 43

Describe methods of conservation in the Maasai Mara

Answer 43

-tourism operators pay conservancies payment for wildlife conservation (PWC) -

Question 44

Describe the problem with peat bogs in the UK

Answer 44

Peat bogs are over harvested for compost but the provide a habitat for many species and have high area of biodiversity. The UKBAP aims to conserve this biodiversity

Question 45

What has caused damage to the biodiversity of the Galapagos islands

Answer 45

Increased tourism