Topic 28 -Landscape Ecology

Question 1

Landscapes are

Answer 1

a collection of communities that exist as patchwork assembly called a mosaic

Question 2

Landscape ecology

Answer 2

study of the causes and consequences of this spatial variation

focuses on features such as distribution, shape, and spatial arrangement of patches

Question 3

Naturally occurring patches reflect

Answer 3

regional variations in geology, topography, soil and climate
conducted at different scales

Question 4

5 types of landscape structure

Answer 4

Large vs small patches 
how dispersed patches are
shape of patches (simple vs complex) 
how fragmented the landscape is 
landscape scale

Question 5

Grain

Answer 5

the smallest homogenous unit that is the focus of the study

Question 6

Extent

Answer 6

the total area/time period covered

Question 7

Island Biography theory assumption

Answer 7

larger islands (habitat patch) hold more species than smaller islands

Question 8

number of species on an island is determined by the dynamic equilibrium between

Answer 8

colonization and extirpation

Question 9

as the number of species increases, the rate of colonizing successfully

Answer 9

decrease because early arrivals use up available habitats and resources (fundamental niches)

Question 10

as the number of species increases, the rate of species being extirpated

Answer 10

increases, due to: Competition increases -competitively dominant species outcompete others

Question 11

equilibrium species richness (S) is reached when

Answer 11

colonization = extirpation

species richness is stable but species composition can change

Question 12

Distance between islands and island size influences

Answer 12

colonization, extirpation and the equilibrium species richness (S)

Question 13

two predictions about island distance and size

Answer 13

as the distance between patches increases, colonization rates will decrease leading to lower S

a larger patch will have lower rates of extirpation leading to a higher S

Question 14

Application of IBT

Answer 14

important because one of the main causes of anthropogenic extinction is habitat destruction/loss

habitat destruction results in highly fragmented landscapes -leaving much smaller habitat patches that are farther apart relative to natural conditions

Question 15

each habitat patch is composed of

Answer 15

Interior -habitat has its own environmental conditions and community structure

Edge or border -transition zone where community structure and environmental conditions of adjacent patches are blended

Question 16

edge effect

Answer 16

diverse environmental conditions allow edges to support high species diversity

Question 17

interior species require

Answer 17

the stable environmental conditions of interior habitats

no abrupt changes in abiotic/biotic conditions associated with border environments

Question 18

Edge species can survive

Answer 18

under the unstable (variable) conditions of the edge habitat

Question 19

size and shape of habitat patches together affect the

Answer 19

edge: interior habitat ratio

as patch size increases -edge: interior decreases
small patch -mostly edge habitat
large path -mostly interior habitat

as patch width increases edge: interior decreases
long, narrow -mostly edge habitat
square or circular -mostly interior

Question 20

as the ratio of edge: interior habitat changes, so will the diversity of the community….

Answer 20

should have higher diversity with increasing edge habitat but only if interior habitat remains