Landscape Ecology

Question 1

What are landscapes made up of?

Answer 1

1. Fragmented habitats
2. Successional habitats
3. Spatial heterogeneity

Question 2

Habitat fragmentation occurs when?

Answer 2

When parts of a habitat are destroyed, leaving behind smaller unconnected areas (Patches!)

• Occurs when there is a fire / volcanic eruption, or even human activity (mainly human activity)

Question 3

Spatial heterogeneity

Answer 3

Uneven distribution of each species within an area.

Question 4

How can we measure landscape variation?

Answer 4

1. Remote sensing across large spatial scales (quantify variation in community)
2. Vegetation ability to absorb or reflect wavelengths of light
3. Ground based research (vegetation maps)

Question 5

What are the implications to the movement and
persistence of species in landscape structures?

Answer 5

• Natural causes of changes in ecosystems include wildfire, disease, and flooding
• Human causes of changes in ecosystems include clearing land for other use, pollution, and introducing invasive species
• Climate change may allow ecosystems to expand while others may face harsh challenges

Question 6

How does landscape structure affect mass and
energy flow or the propagation of disturbance?

Answer 6

influences processes such as the flow of energy, materials, and species between the ecosystem within a landscape

• patch size, patch isolation, patch number important for certain interactions

Question 7

Patch size and disturbance - Baja & Southern California

Answer 7

Baja has frequent fires - however they don’t put them out immediately

Results in higher total area burned but median fire area is less in Baja

Results in a lower total area burned but median fire area is 2x higher in Southern California (Due to windy + dry climate)

Question 8

Why is patch arrangement important?

Answer 8

1. Important for metapopulations
2. Different rates of colonization and extinction
3. Easier movement between patches

Question 9

Metapopulations

Answer 9

Sub-populations of a given species that are linked by dispersal across patchy environments

Question 10

Large patches

Answer 10

Higher in resources and more suitable habitat

• Density declines =
  # of individuals / area
• Population movement also declines

Question 11

Small patches

Answer 11

Fewer resources and less suitable habitat

Question 12

Species-area relationships (Species richness)

Answer 12

The relationship between species richness and size of area

Question 13

Species-area relationships (Distant islands - isolation)

Answer 13

Support fewer species due to where resources are located (mainland)

Question 14

Species-area relationship (Mainland)

Answer 14

Higher amount species because higher resource amount in area

Question 15

Equilibrium model of Island biogeography

Answer 15

The number of species on an island is determined by a balance between species immigration and extinction

Question 16

What happens when immigration occurs in the equilibrium model of Island Biogeography

Answer 16

Rate of immigration of new species to an island decreases as the number of species on the island increases

• Determined by island distance

Question 17

What happens when extinction occurs in the equilibrium model of Island Biogeography

Answer 17

Rate of species extinction increases because the number of species present increases

• Larger potential for extinction to happen from competitive interactions)
• Determined by island size

Question 18

Island biogeography - Predefaunation species

Answer 18

Mass murder of insect species changed the composition however species number did not change