Lesson #2: Biodiversity and Conservation

Question 1

Biodiversity

Answer 1

The number and variability of species in a given ecosystem.

The biodiversity of an ecosystem is an indicator of overall health of
that ecosystem.

Biodiversity as an indicator of ecosystem health has two components;
richness and evenness.

Richness – the number of different species present.

Evenness – how close in number each species is.

Question 2

Simpson’s Diversity Index

Answer 2

Low species diversity suggests:

relatively few successful species in the habitat the environment is quite stressful with relatively few ecological niches and only a few organisms are really well adapted to that environment food webs which are relatively simple change in the environment would probably have quite serious effects

High species diversity suggests:

a greater number of successful species and a more stable ecosystem more ecological niches are available and the environment is less likely to be hostile
complex food webs environmental change is less likely to be damaging to the ecosystem as a whole

Question 3

Biotic Index

Answer 3

Indicator Species

An indicator species is an organism that occurs only when specific
environmental conditions are present.

The Biotic Index

A biotic index compares the relative frequency of indicator species.

Each indicator species has a specific pollution tolerance factor that can be
multiplied by the number of individuals of that species in the area. A
weighted average is produced in order to determine the biotic index.

This biotic index is used to determine the conditions in area.

Question 4

Species Conservation

Answer 4

It is important to preserve the biodiversity of the planet for a
sustainable future.

Many species have disappeared throughout our history and still
others are decreasing rapidly

Species are assigned a conservation status to help determine the
amount of resources required to help grow or maintain the
population.

Question 5

Conservation Status

Answer 5

Many different classification systems exist in the world and species
may have a different conservation status in different parts of the
world. Some common assigned statuses are:

Least Concern – lowest risk

Vulnerable – high risk of endangerment in the wild

Endangered – high risk of extinction in the wild

Critically Endangered – extremely high risk of extinction in the wild

Extinct in the wild – known only to survive in captivity

Extinct – no known living individuals

Question 6

In situ Conservation

Answer 6

This type of conservation involves the active management of nature
reserves or national parks.

This allows endangered species to remain in their habitat and
interacting this other wild species that helps maintain their niche.

A nature reserve is an area that is specifically designated for the
conservation of wildlife. However, establishing a nature reserve may
not be enough and active management may be required.

Active management could include; removal of alien plant species,
reintroduction of extirpated species, re-wetting of wetlands,
controlling poaching and feeding the animals.

Question 7

Ex situ Conservation

Answer 7

Conservation is species outside of their natural habitat. This may take
many different forms depending on the species.

Plant species can be grown in botanic gardens or the seeds stored in a
seed bank.

Captive breeding of animals may sometimes be used and the
offspring eventually released into their natural habitat.

This type of conservation is used in cases where it is too dangerous
for the animals to stay in their natural habitats.