Biodiversity 7 - Conservation techniques

Question 1

Explain IUCN Red Lists

Answer 1

• Species are classified by the IUCN Red List into nine groups, specified through criteria such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmentation.
• There is an emphasis on the acceptability of applying any criteria in the absence of high quality data including suspicion and potential future threats, “so long as these can reasonably be supported”.

Question 2

Explain the IUCN Red List abbreviations

Answer 2

• Extinct (EX) – beyond reasonable doubt that the species is no longer extant.
• Extinct in the wild (EW) – survives only in captivity, cultivation and/or outside native range, as presumed after exhaustive surveys.
• Critically endangered (CR) – in a particularly and extremely critical state.
• Endangered (EN) – very high risk of extinction in the wild, meets any of criteria A to E for Endangered.
• Vulnerable (VU) – meets one of the 5 red list criteria and thus considered to be at high risk of unnatural (human-caused) extinction without further human intervention.
• Near threatened (NT) – close to being at high risk of extinction in the near future.
• Least concern (LC) – unlikely to become extinct in the near future.
• Data deficient (DD), Not evaluated (NE)

Question 3

Explain habitat preservation

Answer 3

• Species diversity and level of endemism – e.g. saving biodiversity hotspots will save a wider variety of organisms
• Size of the piece of land
• Level of threat or “importance” of species living there (Rare species; Endemic species)
• “Naturalness” of the area

Question 4

Explain SA Biomes

Answer 4

• Fynbos ( western cape )
• Grassland ( middle )
• Nama Karoo ( half of northern cape )
• Succulent Karoo ( above fynbos )
• Savanna ( around grasslamd )
• Indian ocean coastal belt ( east coast )
• Albany Thicket
• Desert

Question 5

Explain keystone species

Answer 5

• A species that plays a vital role in an ecosystem
• Have a disproportionate effect relative to their abundance
• Loss of a keystone species can have a dramatic effect on the entire ecosystem
• The survival of other species in the community depends on the survival of the keystone species

Question 6

Explain flagship species

Answer 6

• Species chosen to represent an environmental cause, such as an ecosystem in need of conservation
• Chosen for their beauty, cuteness or distinctiveness in order to best engender support from the public - charisma
• Evoke an emotional response in humans

Question 7

Explain indicator species

Answer 7

• Species used to monitor the health of an ecosystem
• Vulnerable to environmental changes

e.g. Amphibians

Question 8

Explain metapopulation

Answer 8

• Greater population subdivided into several smaller populations, isolated by habitat fragmentation
• The populations generally function independently of each
  other: subject to dispersal

Source population:
 Favourable conditions  Births > deaths
 Net emigration

Sink population:
 Less favourable conditions  Deaths > births
 Net immigration

Question 9

Explain habit restoration

Answer 9

• Is a branch of conservation biology that attempts to restore damaged or destroyed ecosystems to their former state
• Complete restoration may not always be possible if the original state is unknown
• However, the goal is to return an area to a more desirable condition with a particular species community and ecosystem function

Question 10

Explain habitat restoration principles

Answer 10

1. Begin as soon as possible, before the remaining fragments are lost
2. Once the natural history is understood, use biological techniques to mimic natural processes, e.g. use controlled burns to mimic natural fires
3. Goal is sustainable usage – the restored ecosystem must be able to sustain itself