Fish assemblage

Fish assemblageFish assemblage

Coldwater fishesColdwater fishes

CyprinidsCyprinids

SalmonidsSalmonids

CatostomidsCatostomidsBenthic fishesBenthic fishes

Scaling of fish assemblages and habitat Scaling of fish assemblages and habitat

relationshipsrelationships

Patchiness in fish distribution Patchiness in fish distribution ((WARMWARM stream) stream)

COOLCOOL stream stream

COLDCOLD stream stream

Distance upstream (km)

65 75 85 95 105 115

Gra

die

nt (

%)

0.2

0.4

0.6

0.8

1.0

Ma

x. d

ep

th (

m)

0.4

0.5

0.6

0.7

0.8

Ha

bita

t typ

e

1.5

2.0

2.5

3.0

Re

lativ

e a

bu

nd

anc

e

0.0

0.5

1.0

1.5

juvenile chinook

MFJD

max. depth

habitat type

gradient

Spatial Spatial variability of variability of juvenile juvenile chinook in achinook in a WARMWARM streamstream

Middle Fork John Middle Fork John Day RiverDay River

Distance upstream (km)

100 110 120 130 140 150 160

Gra

dien

t (%

)

0.5

1.0

1.5

2.0

Max

. dep

th (

m)

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Hab

itat t

ype

0.5

1.0

1.5

2.0

2.5

Rel

ativ

e ab

unda

nce

0

1

2

3

NFJD

bull trout

juv. chinook

habitat type

max. depth

gradient

North Fork John North Fork John Day RiverDay River

COOLCOOL stream stream

Distance upstream (km)

0 5 10 15 20 25 30 35

Gra

dien

t (%

)

0.4

0.8

1.2

1.6

Max

. dep

th (

m)

0.5

1.0

1.5

2.0

Hab

itat t

ype

2.0

2.5

3.0

Rel

ativ

e ab

unda

nce

0

1

2

3

WENjuv. chinook

bull trout

habitat type

max. depth

gradient

Wenaha RiverWenaha River

COLDCOLD stream stream

MFJD

Distance upstream (km)

60 70 80 90 100 110 120

Axi

s sc

ore

0.04

0.06

0.08

0.10

0.12

0.14Axis 1Axis 2

Multivariate Multivariate analysis of analysis of community community structurestructure in a in aWARMWARM streamstream

Middle Fork John Middle Fork John Day RiverDay River

COOLCOOL streamstream

North Fork John North Fork John Day RiverDay River

NFJD

Distance upstream (km)

100 110 120 130 140 150 160

Axi

s sc

ore

-1.0

-0.5

0.0

0.5

1.0

Axis 1Axis 2

COLDCOLD streamstream

Wenaha RiverWenaha River

WEN

Distance upstream (km)

0 5 10 15 20 25 30 35

Axi

s sc

ore

-1.2

-0.8

-0.4

0.0

0.4

0.8

Axis 1Axis 2

Within-streamWithin-stream variabilityvariability

North Fork John North Fork John Day RiverDay River

Downstream Downstream sectionsection

Scale-dependent relationshipsScale-dependent relationships

Effects of spatial Effects of spatial extent on ecological extent on ecological relationshipsrelationships (Nekola and Wagner 2001)(Nekola and Wagner 2001)

• Thermal crossover Thermal crossover between warm- and between warm- and coldwater species coldwater species 20-22°C 20-22°C

Torgersen, C. E., C. V. Baxter, H. W. Li, and B. A. McIntosh. 2006. Landscape influences on longitudinal patterns of river fishes: Spatially continuous analysis of fish-habitat relationships. Pages 473-492 in R. M. Hughes, L. Wang, and P. W. Seelbach, editors. Landscape influences on stream habitats and biological assemblages. American Fisheries Society, Bethesda, Maryland.