Island Ecology

Question 1

Give the key evolutionary factor of islands

Answer 1

Usually have rapid evolution of species.

Question 2

Why are islands usually badly damaged ?

Answer 2

Due to agriculture, tourism, alien species

BUT usually have huge scope for restoration.

Question 3

How can eco tourism be done well ?

Answer 3

When it is non intrusive and run by local people.

Question 4

Give some examples of islands.

Answer 4

Lakes (within sea of land)
Mountain tops (high altitude)
Habitat fragmentation
(Heathland, Caledonian pine)

Question 5

State some species area relationships

Answer 5

Islands have fewer species in comparison to the mainland

Big islands have more species than small islands

Close to shore islands have more species than those further away

Question 6

Give the 2 reasons for species area relationships

Answer 6

Habitat diversity
More habitats on continents

Equilibrium theory
The number of species on an island is a balance between immigration and emigration/extinction.

Question 7

On a blank island, describe the graph for immigration.

Answer 7

Will start high (island blank space)

Will be higher immigration rate for closer or large islands

Immigration rate will decline until you reach the number of resident species

Question 8

On a blank island, describe the graph for extinction

Answer 8

Will start at 0

Will increase randomly due to unnatural and natural means

Question 9

Where is the dynamic species pool on an island ?

Answer 9

In the crossover between extinction and immigration.

Here the population is at equilibrium.

Question 10

What does habitat fragmentation lead to ?

Answer 10

Islands

Question 11

Give some examples of habitat fragmentation.

Answer 11

Ancient broadleaf woodlands
Heathlands
Caledonian pine forest
Tropical rain forest

Question 12

Give the 2 main effects of habitat fragmentation.

Answer 12

Reduced Area

Edge effect
Habitats will differ from the centre of the habitat to the outside edge

Question 13

What is prone to extinction following fragmentation ?

Answer 13

Predators
Large species
Habitat specialists

Question 14

Why is edge effect damaging in habitat fragmentation ?

Answer 14

Proportionally more of the habitat will be affected and degraded
Light, wind, water have a bigger impact

Question 15

How can we prevent habitat fragmentation ?

Answer 15

Wildlife corridors

Question 16

What are the disadvantages of wildlife corridors ?

Answer 16

They are expensive
Difficult to maintain
No field evidence that they are effective until recently

Question 17

Can wildlife corridors slow rates of extinction

Answer 17

Yes, research by the university of Nottingham at the peak district revealed this.

Question 18

Wildlife corridors benefit predators more than non predators, True or False ?

Answer 18

True

Question 19

Describe the cascading effect of the large frugivores going extinct on the palm population, in the Brazilian Atlantic Forest

Answer 19

Large Frugivores extinct
Large seeds no longer consumed by small birds remaining
Palms Reduce seed size
Increases seed mortality (reduced energy reserve) in dry conditons
Small seeds produce smaller saplings
Overal decrease in fitness of palm population

Question 20

What do nature reserves in the modern world need to be ?

Answer 20

Bigger, Better and more connected

Question 21

What is edge effect ?

Answer 21

Where habitat differ from the centre of the habitat to the outside edge