using a possum’s parentage to predict possible pathways across landscapes
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Using a possum’s parentage to predict possible pathways across landscapes. Thomas R. Etherington. Invasive spread in New Zealand. Brushtail Possum ( Trichosurus vulpecula ). Red Deer ( Cervus elaphus ). adapted from King (2005). Patch-matrix landscape dispersal. ?. ?. ?. ?. ?. ?. ?. - PowerPoint PPT PresentationTRANSCRIPT
SCHOOL OF ENVIRONMENT
Using a possum’s parentage to predict possible pathways across landscapes
Thomas R. Etherington
SCHOOL OF ENVIRONMENT · Geography
Invasive spread in New Zealand
adapted from King (2005)
Red Deer(Cervus elaphus)
Brushtail Possum(Trichosurus vulpecula)
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Patch-matrix landscape dispersal
?
?
?
?
?
?
?
?
Year 1Year 2Year 3Year 4
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Matrix compositionHomogenous
Heterogeneous
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Friction surface
Forest
Grass
Rock
Water
Landscape
1
10
100
1000
Cost
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Least-cost paths
1
10
100
1000
Cost
Start point
End point
Least-cost pathway
a b
c
cd bc = D bc ×C b + C c
2
cd ab = D ab × C a + C b
2
LCP ac = cd ab + cd bc
(D = distance, C = cost)
SCHOOL OF ENVIRONMENT · Geography
Least-cost spread
from Lockwood et al. (2007)
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Connectivity and Relatedness
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?
?
?
??
?
?
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Hawke’s Bay Possum Genetics
from Cowan et al. (2006)
Geneti
c d
ista
nce
Geneti
c d
ista
nce
Euclidean distance (m)
Euclidean distance (m)
Separated by a river
Not separated by
a river
SCHOOL OF ENVIRONMENT · Geography
Hawke’s Bay Possum Genetics
10 Kilometres
N
Wide river
Genetic distance
High
Low
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Acknowledgements