6.6 Populations and Sustainability

What is the lag phase in a population growth graph?

There may be a few individuals which are still acclimatising to their habitat. At this point, the rate of reproduction is low, and the growth in population size is slow

1 of 25

What is the log phase in a population growth graph?

Resources are plentiful and conditions are good. Reproduction can happen quickly, with the rate of reproduction exceeding mortality. The population size increases rapidly

2 of 25

What is the stationary phase in a population growth graph?

Population has levelled out at the carrying capacity of the habitat - the habitat cannot support a larger population. Rate of reproduction and mortality are equal. The population stays stable or fluctuates slightly.

3 of 25

What is a limiting factor?

Factors that limit the growth in population size. Can be density independent such as temperature. Or density dependent such as availability of food water, light, shelter, level of predation, parasitism.

4 of 25

What are the two types of Strategist?

r-Strategist (exceed population capacity before limiting factors start to have an effect, boom then bust). k-strategist (population size is determined by the carrying capacity)

5 of 25

Describe features of an animal that is a k-strategist

Examples are birds and larger mammals e.g. humans. They exhibit: low reproductive rate, slow development, late reproductive age, long lifespan, larger body mass.

6 of 25

Describe features of a r-strategist

Examples are mice, insects, spiders and weeds. They exhibit: high reproductive rate, quick development, young reproductive age, short life span, small body mass

7 of 25

Describe Predator and Prey relationships

When predator population increases, they eat more prey. Prey population decreases leaving less food for predators. Fewer predators can survive and population decreases. With fewer predators, fewer prey are eaten and their population increases.

8 of 25

What are the two types of competition exhibited in populations

Intraspecific and Interspecific

9 of 25

What is Intraspecific competition?

Competition between individuals of the same species. If population size drops, competition reduces and the population size increases. If population size increases, competition increases and the population size drops

10 of 25

What is interspecific competition?

Competition between individuals of different species. If two species have exactly the same niche, one is out competed by the other and dies out or becomes extinct in that habitat.

11 of 25

What is preservation?

Maintenance of habitats and ecosystems in their present condition, minimising human impact

12 of 25

What is conservation?

Maintenance of biodiveristy, including diversity between species, genetic diversity within species, and maintenance of a variety of habitats and ecosystems.

13 of 25

What are the threats to biodiversity?

Over-exploitation of wild populations for food, sport or commerce (harvested faster than they can replenish). Habitat disruption due to agricultural practices, pollution or widespread building. Species introduced to ecosystems that out-compete others

14 of 25

Describe some conservation strategies

Raising carrying capacity by providing extra food, move individuals to encourage dispersion, fencing in populations, control predators and poachers, vaccination, preventing pollution, deflect succession (coppicing)

15 of 25

What are the reasons for conservation?

Ethics (species have value, humans have ethical responsibility to protect them). Economic and Social (plant species provide food, maintain genetic diversity, potential drug uses, natural predators act as control agents, ecotourism, recreation)

16 of 25

Describe a small scale sustainable timber production

Coppicing, deciduous tree cut close to ground, shoots grow from surface and mature into stems that can be used for fencing, firewood or furniture. Pollarding is similar but higher up to prevent deer eating. Rotational coppicing is good for biodiversi

17 of 25

Describe a sustainable method for large scale timber production

Any tree harvested is repalced by another, forest must maintain ecological function (biodiversity, climate and water cycles). Local people should benefit. Foresters also control pests and pathogens, plant well known trees and position trees optimum

18 of 25

How are sustainable fish stocks managed

Over-fishing is avoided to prevent reducing fish popualtions to zero, maintain popualtions at carrying capacity. No permament damage to habitats. Fishing must adapt to regulations internationally. Aquaculture

19 of 25

Describe the conflict between conservation and human needs in Terai Region

Local people need forests for fuel, animal feed, food, building materials, tools and medicine. Forest corridors help disperse bengal tigers. Counteracting poachers and illegal felling. WWF introduced biogas and wood-efficient stoves to lower demand

20 of 25

Describe the conflict between conservation and human needs in Maasai Mara

Partnerships between conservancies and tourism operators, land set aside for conservation. Land-owners have to move lifestock out during tourist season, land owners have to settle outside. Positive social outcomes, as well as positive conservation

21 of 25

Describe the conflict between conservation and human needs in Peat Bogs

Wetlands support high biodiversity, used in compost. UK biodiversity Action plan aims to conserve and enhance biodiversity through local level schemes. End commercial use of peat in the UK, identified peat bogs for restoration

22 of 25

Describe the human effects on the Galapagos Islands

Habitat disturbance (increased human population, greater demands, building and agriculture) Over exploitation (over fishing). Introduced species (alien species introduce competition, disease and destroy habitats)

23 of 25

Describe how human effects are currently managed on Galapagos Islands

Culling of pests and predators over-exploiting native species. Arriving boats searched for foreign species. Educating natives on conservation

24 of 25

How are human effects controlled in the Antarctic

Quotas stopping over exploitation of krill (food source for penguins, fish whales). Protected Areas (illegal to hunt whales) Bird scaring fishing lines (prevent killing albatrosses and petrels)

25 of 25

Get Revising

6.6 Populations and Sustainability

Other cards in this set

Card 2

Front

Back

Card 3

Front

Back

Card 4

Front

Back

Card 5

Front

Back

Comments

Similar Biology resources:

Other cards in this set

Card 2

Front

Back

Card 3

Front

Back

Card 4

Front

Back

Card 5

Front

Back

Comments

Related discussions on The Student Room

Similar Biology resources: