C.4 Conservation of biodiversity

Question 1

How have humans affected the environment?

Answer 1

• Industrial pollution
• Agricultural expansion
• Increased urbanisation
• Pollution of land, sea and atmosphere

Question 2

Define In-situ conservation

Answer 2

It’s a way to conserve a species by protecting them in their natural environment. It can be done through nature reserves or preservation parks.

Question 3

Define Ex-situ conservation

Answer 3

It’s a way to conserve a species by protecting it off site away from its natural habitat. Can be done through zoos or seed banks or botanical gardens.

Question 4

Define Indicator species

Answer 4

It is a species that only occurs when specific environmental conditions are met.

Question 5

How are lichens indicator species?

Answer 5

Lichens are composite organisms made up of fungi and algae in a mutualistic relationship. They act as indicators of air pollution, especially sulphur dioxide. The bushy beard lichen is unable to tolerate even low levels of sulphur dioxide within the atmosphere. Therefore if this lichen is absent it may indicate high levels of sulphur dioxide.

Question 6

How are adult frogs and toads indicator species?

Answer 6

They have moist permeable skin and are therefore susceptible to airborne pollutants that enter their skin. Their presence or absence indicates levels of atmospheric pollution. Likewise, tadpoles live in water and their number can indicate the quality of the water in which they live.

Question 7

What is a biotic index?

Answer 7

It is a value derived from a wide range of indicator species that have varying degrees of tolerance towards abiotic factors such as oxygen levels, sulfur dioxide concentrations.

Formula: Σ (organisms × Tolerance rating) / Σ organisms collected

Question 8

Why are benthic macro-invertebrates used for biotic index?

Answer 8

• They are slow movers so they are easy to measure
• They live majority of life in water and are abundant in water ways around the world
• They take in oxygen to survive, therefore their presence or absence can indicate the amount of oxygen present in the water.

Question 9

Elaborate In-situ (on site) conservation

Answer 9

They are measures to protect and manage nature reserves and involves:

• Restoring areas that have been destroyed
• Protecting species from poachers
• Protecting species from invasive species
• Protecting nature reserves from pollution

They protect communities by setting up perimeters where there is controlled access.

Question 10

What forms does Ex-situ (off site) conservation exist in?

Answer 10

They exist in forms of:

• Captive breeding programs where animals are kept within enclosures and breeding to increase population to later re-introduce them to their natural habitat.
• Botanical gardens where plants are preserved and kept within urban areas. Easier with plants than animals.
• Seed banks where seeds are stored in order to protect biodiversity

Question 11

What difficulties do captive breeding programs face?

Answer 11

• Slow conception rate
• Low fertility rate
• Difficulty to be released into the wild due to lack of survival skills

Question 12

Explain the case study of the giant panda.

Answer 12

They are one of the most endangered species with only 2500 pandas left. They are difficult to breed in captivity due to

• Low breeding rates
• Difficulty to find a partner
• 60% of all cubs born die at infancy.

However there were two changes that improved the breeding.

• First was artificial insemination
• Second was improved husbandry (caring for animals) techniques.

There have been several attempts to reintroduce the pandas to the wild. However many have died due to lack of survival skills. As pandas are a national treasure there are tensions around this as many criticise those responsible for the release of pandas.

Question 13

What is evenness in biodiversity?

Answer 13

It refers to the comparison of equality of numbers within each species.

Question 14

Explain Simpsons reciprocal index of diversity

Answer 14

The greater the value of the index the greater the biodiversity in an area.

Formula: D=N(N-1)/Σn(n-1)

Question 15

What are biogeographic factors?

Answer 15

These are factors that affect the distribution of species. In conservation terms they include:

• Habitats
• The edge effect
• Island size

The three factors impact the success of nature reserves

Question 16

What are biogeographic factors?

Answer 16

These are factors that affect the distribution of species. In conservation terms they include:

• Habitats
• The edge effect
• Island size

The three factors impact the success of nature reserves

Question 17

Explain the Edge effect.

Answer 17

The edge effect is the change in ecosystems, communities and habitats at the edge of nature reserves. There is an increase in interactions between biotic factors and abiotic factors (roads, rivers, fences).

There may be an increase in abiotic factors such as:

• Increased poaching
• Increased light penetration
• Increased temperature

Question 18

Unesco has recommended what three boundary zones to avoid the edge effect?

Answer 18

• Core area
• Buffer zone
• Transition zone

Question 19

Island size refers to the idea that larger reserves are better than smaller reserves, why is this?

Answer 19

Larger reserves can:

• Sustain more ecosystems, habitats and species
• Decrease negative impact from edge effect
• Can give resources needed for larger species
• Allows for migration

Question 20

What are wild life corridors?

Answer 20

They link similar wildlife habitats. It decreases fragmentation and minimises the impacts of the edge effect. It allows for migration and interbreeding of animals and plants.

Question 21

What is fragmentation?

Answer 21

Some reserves have fragmentation which refers to when nature reserves are split into multiple sections due to for example building of roads. The negative impact of this are:

• Increased edge effect
• Isolation of population
• Lack of provision for larger species