populations and sustainability

Question 1

what is a population?

Answer 1

the number of individuals of the same species in a particular area

Question 2

describe the stages in a population graph

Answer 2

lag phase -> log phase -> carrying capacity -> death phase

Question 3

what shape is the population growth curve?

Answer 3

s shape

Question 4

what is the lag phase?

Answer 4

only few individuals, still acclimitising to their habitat. initial small population size means few births. growth in pop. size is slow

Question 5

what is the log phase?

Answer 5

plenty of resources, optimal conditions. rate of reproduction exceeds death rate and pop. growth is rapid

Question 6

what is carrying capacity?

Answer 6

stationary phase where habitat cannot support larger population. reproduction rate and death rate are equal

Question 7

what is the death phase?

Answer 7

when death rate exceeds birth rate

Question 8

what are limiting factors?

Answer 8

factors that limit the growth in population size

Question 9

what are density dependent limiting factor examples?

Answer 9

availability of resources, parasitism, disease, predation and competition. acts mores strongly as size increases

Question 10

what are density independent limiting factor examples?

Answer 10

temperature changes, earthquakes, fires. act strongly irrespective of population size

Question 11

what are k strategists?

Answer 11

species that have population sizes determined by carrying capacity. limiting factors exert increasingly significant effect as pop. size reaches carrying capacity (e.g. birds,animals)

Question 12

what are some characteristics for k strategists?

Answer 12

long lifespan, late reproductive age, slow development, larger body mass, low reproductive rate

Question 13

what are r strategists?

Answer 13

species in which the population size increases so quickly that it can exceed the carrying capacity before limiting factors start to have an effect

Question 14

what are some characteristics for r strategists?

Answer 14

short lifespan, small body mass, high reproductive rate, quick development, young reproductive age

Question 15

describe the population growth graph for r strategists

Answer 15

once carrying capacity exceed -> death phase of boom -> bust
could be due to resources running out

Question 16

are predators or prey always smaller in number on predator-prey graph

Answer 16

predators

Question 17

what are the types of competition?

Answer 17

intraspecific and interspecific

Question 18

what is the competitive exclusion principle?

Answer 18

2 species cannot occupy the same niche

Question 19

what is a case study of interspecific competition?

Answer 19

P.aurelia and P.caudatum have an overlap in the niche so more intense competition. P.caudatim dies out due to comp. and is outcompeted for food

Question 20

what is conservation?

Answer 20

humans actively managing a resource, habitat or ecosystem o maintain or restore biodiversity

Question 21

what is preservation?

Answer 21

the resource of habitat is left untouched by humans. this can mean that the ecosystem changes over time (succession)

Question 22

what are sustainable methods of small scale timber production?

Answer 22

coppicing (where tree trunks cut close to ground so new shoots form from cut surface and mature). rotational coppicing. pollarding (trunk cut higher up than coppicing)

Question 23

what are sustainable methods of large scale timber production?

Answer 23

selective cutting (removing largest trees). replace trees through replanting rather than waiting for natural regeneration. plant trees far enough from each other. manage pests and pathogens. ensure areas of forest remain for indigenous ppl

Question 24

what are sustainable methods for fishing?

Answer 24

international agreements, fishing quotas, using nets of different mesh sizes, allowing commerical and recreational fishing only at certain times of the year, reintroducing fish farming to maintain the supply of protein food & preventing the loss of wild species

Question 25

case study: terai region of nepal

Answer 25

problem -> overgrazing, over exploitation of forest, expansion of agriculture into forested areas
solution -> employment for sustainable jobs, conservation of areas has spread, improve soil & water management

Question 26

case study: masai mara

Answer 26

problem -> poachers for elephants, overgrazing, overcultivation
ecotourism -> support conservation, no exploitation
research -> employment of reserve rangers, provision of communication equipment, has helped lion, buffalo etc

Question 27

case study: galapagos islands

Answer 27

methods to reduce human activity -> limiting area tourist, controlling livestock movement, introducing anti poaching measures, replanting forests, limiting hunting (quotas) galapagos national park -> park rangers, strict control

Question 28

case study: antartica

Answer 28

1961 antarctic treaty -> signed by 12 countries, nuclear explosives banned, disposal of radioactive waste
effect of human activity -> global warming, hunting of whales and seals, soil contamination, discharge of waste into seas

Question 29

case study: uk conservation

Answer 29

snowdonia national park -> conserve natural beauty in park
lake district -> regions of moorland. wide range of wildlife. replanting native tree species