6.6 population and sustainability

Question 1

define carrying capacity

Answer 1

the maximum population size that can be maintained over a period of time in a particular habitat

Question 2

Define limiting factor

Answer 2

the factor whose magnitude slows down the rate of a natural process

Question 3

What are the three phases of population growth

Answer 3

lag phase
log phase
stationary phase(carrying capacity)

Question 4

describe the lag phase

Answer 4

may only be a few individuals and they are still acclimating to their habitat and at this point rate of reproduction is low and growth in population is slow

Question 5

describe the log phase

Answer 5

resources are plentiful and conditions are good
reproduction happens quickly and the rate exceeds mortality
population size increases rapidly

Question 6

describe the stationary phase

Answer 6

the population size has levelled out at the carrying capacity of the habitat and the habitat cannot support a larger population

the rate of reproduction and mortality equal and the population size remains fairly stable

Question 7

What are the two different types of limiting factors

Answer 7

density independent
density dependant

Question 8

describe how limiting factors can be density independent

Answer 8

they act strongly irresponsive of the size of the population for example low temperatures will kill the same proportion of the population irrespective of its size

Question 9

Describe how limiting factors can be density dependant

Answer 9

where the factor increases the population more strongly as population size increases for example the availability of resources

Question 10

what are the 2 different types of strategists

Answer 10

k-strategists and r-strategists

Question 11

describe the characteristics of k-strategists

Answer 11

low reproductive rate
slow development
long lifespan
larger body mass

Question 12

Define k-strategists

Answer 12

species whose population size is determined by the carrying capacity and limiting factors exert a more and more significant effect as population size gets closer to the carrying capacity

Question 13

Describe the characteristics of r-strategists

Answer 13

high reproductive rate
quick development
short life span
small body mass

Question 14

define r-strategists

Answer 14

its population can grow very quickly and surpass carrying capacity before the limiting effectors begin to have an effect and once carrying capacity has been surpassed there is a shortness of resources
‘boom and bust’

Question 15

define interspecific competition

Answer 15

competition between individuals of different species

Question 16

define intraspecific competition

Answer 16

competition between individuals of the same species

Question 17

what can the relationship between predator and prey be described as

Answer 17

cyclic

Question 18

Describe the predator and prey relationship

Answer 18

when prey populations get smaller predators have less food so their populations decrease
the decrease in predator populations leads to increased prey populations as theyre are less predators hunting them
and as prey populations begin to rise so do predator a they have more food

Question 19

describe how intraspecific competition keeps population sizes relatively stable

Answer 19

If the population size drops there will be less competition and population size increases and vice versa

Question 20

what experiment did Gause do

Answer 20

he grew two species of paramecium both separately and together as an investigation into interspecific competition

Question 21

What did Gause conclude from his experiment

Answer 21

that the more overlap there was between two species niche’s results in more intense competition and one can be out-competed by the other and die out of become extinct in the habitat

Question 22

Define conservation

Answer 22

maintenance of biodiversity including diversity within species and maintenance of a variety of habitats and ecosystems

Question 23

define preservation

Answer 23

maintenance of habitats and ecosystems in their present conditions and minimising human impact

Question 24

What are some threats to biodiversity

Answer 24

over-exploitation
habitat destruction
species introduced to an ecosystem by humans that outcompete native species

Question 25

What are some conservation strategies

Answer 25

control predators and poachers move individuals to enlarge populations preserve habitats by preventing pollution vaccinate individuals against disease

Question 26

Why conserve biodiversity

Answer 26

ethics economic and social reasons

Question 27

define coppicing

Answer 27

the stem of a deciduous tree is cut close to the ground and once cut new shoots from the cut surface grow and mature into narrow stems

Question 28

define pollarding

Answer 28

cutting the stem higher up to prevent deer eating the emerging shoots

Question 29

what is rotational coppicing

Answer 29

dividing a forest into sections and cut one section each year so by the time they want to coppice again the new stems have matured and are ready to be cut

Question 30

Why is rotational coppicing beneficial

Answer 30

it is good for biodiversity it lets more light in provides different types of habitat

Question 31

Explain why in the past large-scale timber production was bad

Answer 31

Destroyed habitats, reduced mineral levels in soil and left soil susceptible to erosion. Soil may run off into waterways polluting them

Question 32

describe modern sustainable forestry techniques

Answer 32

any tree harvested is replaced with another tree either grown naturally or planted the forest must maintain its ecological function local people should benefit from the forest selective cutting control pests and pathogens

Question 33

how do you manage fish stocks

Answer 33

fisheries and aquacultures

Question 34

what are the three principles for sustainable management of fisheries

Answer 34

fishing must take place at a level which allows it to take place indefinitely fishing must be managed to maintain the structure a fishery must adapt to changes in circumstances and comply with regulations

Question 35

What are the benefits and disadvantages of aquaculture rather than capture fisheries

Answer 35

aquaculture can provide sustainable fish stocks restricting impact on oceanic fish stocks It is expected to feed more people than capture fisheries

Question 36

Where is the Terai region

Answer 36

In the south of Nepal

Question 37

What are some characteristics of the Terai region

Answer 37

It is made up of marshy grasslands, savannah and forests it is densely populated and home to endangered species such as the bengal tiger

Question 38

What has been the effect of human activity in the Terai region

Answer 38

it has been under pressure for the expansion of agriculture into forested areas grazing from farm animals, over exploitation of forest resources and replacement of traditional agricultural crop varieties

Question 39

Describe how the Terai region has been managed

Answer 39

the WWF were focused on conserving the forest landscape. They introduced community forest initiatives local people had rights to exploit the forest as well as responsibilities to look after it. Biogas schemes and wood-efficient stoves were introduced to reduce the demand for firewood eradicating invasive species creation of forest corridors between national parks

Question 40

Has the management of the Terai region been successful

Answer 40

yes, the tiger population has been steadily growing due to their use of the corridors

Question 41

Where is the Maasai Mara

Answer 41

It is a famous destination for wildlife watchers in Kenya

Question 42

Describe the characteristics of the Maasai Mara

Answer 42

It has large populations of antelopes and other large mammals It has high endemic poverty but a lot of tourism so there had been a scope to develop conservation compatible land use that rewards local people financially and conserves habitats and species that are the basis of tourism

Question 43

Describe how the Maasai Mara is conserved

Answer 43

creation of National parks in 1945 Rest of the land was used agriculturally as many Maasai took tenure of small plots of the land PWC - conservancies that set an area of land aside for conservation which have positive social and economic outcomes

Question 44

What are the negative consequences of conservancies

Answer 44

land-owners must move their livestock out during tourist season and their are constraints on how they use their land

Question 45

Describe how peat forms

Answer 45

where lack of oxygen prevents complete decomposition of organic matter usually in a waterlogged area

Question 46

what are some threats to peat bogs

Answer 46

Pressure from expansion of agriculture and forestry as well as landfill and peat extraction means that lowland peat bogs now covers less than a 1/10th of its original cover

Question 47

What has been the effect of human activity on the Galapagos islands

Answer 47

50% of vertebrae and 25% of plant species are endangered 2001 oil spill death of 150 000 sharks/year invasive species increasing competition for resources and can eat native species

Question 48

How are the effects of human activity managed in the Galapagos islands

Answer 48

at least 36% of coastal areas have become 'No-Take' zones removal and prevention of invasive species treat the problems caused by the invasive species

Question 49

What are some threats to biodiversity in the lake district

Answer 49

Spruce and pine in conifer plantations support limited biodiversity invasive species such as rhododendron outcompete native species cliff, rock and scree communities are damaged by climbers and walkers

Question 50

What are some solutions to the threats to biodiversity in the Lake district

Answer 50

varied planting invasive species are physically removed seasonal restriction on walking farmers are paid to maintain hay meadows

Question 51

What are the impacts of humans on Snowdonia

Answer 51

farmers dig open drainage ditches which increase risk of flooding due to increased run off conifers are planted as cash crop heather is no longer burnt so that sheep can graze on it

Question 52

What are the solutions to the impacts on Snowdonia

Answer 52

blocking drainage ditches burning controlled fires before heather gets too old and dry to prevent larger fires