Populations and Sustainability Flashcards Preview

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Flashcards in Populations and Sustainability Deck (40)
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1
Q

What is the lag phase in a population-time graph?

A
  • Only a few individuals
  • Acclimatizing
  • Rate of is low growth in population size is slow
2
Q

What is the log phase in a population-time graph?

A
  • Resources are plentiful, conditions are good
  • Reproduction exceeds rate of mortality
  • Population increases rapidly
3
Q

What is the carrying capacity?

A

Maximum population size that can be maintained. Rates of reproduction and mortality are equal. Is stable.

4
Q

What are examples of limiting factors for a population?

A
  • Low temperatures
  • Availability of resources, water, light, oxygen or shelter
  • Levels of predation
5
Q

What are k-strategists?

A
  • Species whose population is determined by the carrying capacity
  • Populations exert a more and more significant effect as population gets closer to carrying capacity
6
Q

What are some examples of k-strategists?

A

Birds, larger mamls (humans), lions, larger plants

  • low reproductive rate
  • slow development
  • late reproductive rate
  • long lifespan
7
Q

What are r-strategists?

A
  • Population size increases so quickly it can exceed the carrying capacity before limiting factors start to take effect
  • After exceeding carrying capacity there are no longer enough resources to survive
  • Enter death phase
8
Q

What are some examples of r-strategsists?

A

Mice, spiders, insects

  • High reproductive rate
  • Quick development
9
Q

How do predators act as a limiting factor?

A
  1. Population gets bigger, more prey eaten
  2. Prey population gets smaller, less food for predators
  3. Less food so less predators survive, population decrease
  4. Less predators, more prey survives, population increases
  5. With more prey the predator population gets bigger
10
Q

What is competition?

A

If resources are not abundant then there will be competition between organisms for resources

11
Q

What is intraspecific competition?

A

Between individuals of the same species

12
Q

What is interspecific competition?

A

Between individuals of different species. Can affect both population size and distribution.

13
Q

What is conservation?

A

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

14
Q

What is preservation?

A

Maintenance of habitats and species in their present condition minimising human impact

15
Q

What are some reasons for conservation?

A
  • Ethical (humans have a responsibility)
  • Economic and social
  • Animals and plants provide food
  • Genetic diversity in wild strains need for hybrid vigour
  • Natural predators can drive out pests
  • Can boost local tourism
  • Plants a source of medicinal drugs
16
Q

Name some methods of conservation

A
  • Protected ares
  • National Parks
  • Green belt land
  • Sites of special scientific interest
  • Legal protection of endangered species
  • Ex situ protection such as zoos or biological gardens
17
Q

What are some management strategies for conservation?

A
  • Raising carrying capacity by providing extra food
  • Move individuals to enlarge populations
  • Restrict dispersal of individuals by fencing
  • Control predators and poachers
  • Vaccinate individuals against disease
  • Prevent pollution or disruption of habitats
18
Q

What is sustainable Management?

A

Conflict between our need for resources and conservation

19
Q

What is coppicing?

A
  • Tree trunk cut close to the ground
  • Mature into narrow stems
  • Can cut these off use them and they will still grown again
20
Q

What is rotational coppicing?

A
  • Good for biodiversity
  • Different areas of woodland are coppiced at different times
  • This provides different habitats eg let more light in
21
Q

What is pollarding?

A

Cutting the tree higher up

22
Q

What are some examples of small scale timber production?

A

Coppicing. Rotational coppicing. Pollarding.

23
Q

What are some examples of large scale timber production?

A

Clear felling. Selective cutting.

24
Q

What are the consequences of clear felling all the trees in one area?

A
  • Destroys habitats on a large scale
  • Reduces soil mineral levels
  • Leaves soil susceptible to erosion
25
Q

What is selective cutting?

A

Removing largest most valuable trees

26
Q

How must farmers sustainably manage the forest?

A
  • Control pests and pathogens
  • Only plant trees species that will grow well
  • Plant trees optimal distance apart
  • When a tree is harvested make sure it is replaced
27
Q

What are the 3 principles or the Marine Stewardship Council?

A
  • Fishing takes place at a level that allows in to continue indefinitely, avoid overfishing
  • Stocks not depleted
  • Maintain productivity, function and diversity of the ecosystem
28
Q

What is aquaculture?

A

Provide sustainable fish stocks - restricts impact on oceanic fish stocks

29
Q

How have humans impacted earth?

A
  • Increase in population has put a strain on resources
  • Demand for oil has increased
  • Conversion of land for agriculture has resulted in the fragmentation of habitats
30
Q

What has happened in the Terai region?

A
  • Southern Nepal home to endangered species
  • Over exploited for the past 10years, agriculturally
  • Forests provide a source of fuel for local people
31
Q

How are they trying to help the Terai region?

A
  • WWF and Nepalese government focused on conservation of the area
  • Local people could exploit the forest but had a responsibility to look after it
  • Developed water holes and forest corridors to enable animal migration
  • Tiger population use forest corridors, population is growing
32
Q

What has happened in Maasai Mari?

A
  • Savannah region in Kenya
  • Surrounding communities in poverty and rely on tourism for wildlife watching
    1. Masaai people started claiming land for agricultural purposes and livestock mobility reduced
  • Density of wildlife dropped by 65% over last 3 years
33
Q

How are they trying to help Maasai Mari?

A
  • 2005, landowners unionized to conserve their land and generate income
  • Landowners must move their livestock out of conserved areas for tourist season
34
Q

How has habitat disturbance affected the Galapagos Islands?

A
  • Population size increase place demands on water, energy and sanitation
  • More waste and pollution
  • Oil demand increase
35
Q

How has over exploitation of resources affected the Galapagos Islands?

A
  • Giant tortoises used as a food source, 200000 in less than a century
  • Depletion of sea cucumber populations
  • Increase in fishing for exotic fish
  • Shark fin market has led to the deahts of 150, 000 sharks
36
Q

How has introduced species affected the Galapagos Islands?

A
  • New species have eradicated native species
  • Goat: feed on Galapagos rock, outcompete giant tortoise in grazing, disrupt nesting sites
  • Cats hunt a number of species eg lava lizards and young iguanas
37
Q

What has been put in place to help the Galapagos Islands?

A

The Charles Darwin Research Station introduced measures to prevent and limit this:

  • Quarantine System
  • Culling of dominant alien species
  • 26% of coastal areas designated as no take zones
38
Q

What is happening to Krill in the Antarctic and what is the impact?

A
  • Provide food for whales, seals, penguins, albatrosses and squid
  • Easy to fish
  • Fishing boats congregate in areas withe large numbers of Krill
  • Natural predators cannot adapt and find Krill elsewhere easily
39
Q

What is happening to Albatrosses and Petrels in the Antarctic and what is the impact?

A
  • Threatened by pollution, hunting and poaching for eggs
  • Habitat destruction
  • Biggest threat is long line fishing
  • Fishermen trail hooks with bait which the birds eat and swallow the hooks
40
Q

What is the Southern Ocean Whale Sanctuary?

A

Protect whales and marine environment - illegal to hunt and kill whales