Climate-hydrology-ecology interactions

in glacierized river systems

David M. Hannah1, L.E. Brown2 and A. M. Milner1

1School of Geography, Earth and Environmental Sciences,

University of Birmingham, UK. 2School of Geography, University of Leeds, UK.

d.m.hannah@bham.ac.uk

Shrinking glaciers

• Growing evidence indicates glaciers shrinking

• Glacierized basins highly sensitive (most vulnerable) to climate change

(Dyurgerov & Meier, 2005)

atmospheric

circulation

local

climate

energy/ mass

exchange

meltwater generation

and drainage

stream flow

contributions(snow, glacier and groundwater)

physico-chemical

habitat

benthic

communities

Hydrological response?

• Short-term discharge increase (A)

• Longer-term discharge decrease (B C)

• Weaker compensation effect change seasonality

• Glacial/ nival pluvial regime flashier/ inc. disturbance

(Miln

er,

Bro

wn

& H

an

nah

, 2009)

Ecological response?

0 2 4 6 8 10

High

Low

Water temperature (T max)

Chloroperlidae

Leptophlebiidae (NZ)NemouridaeLeuctridae

HeptageniidaeRhyacophilidaeChironominae

Limnephilidae

PerlodidaeTaenioplerygidae

BaetidaeSimuliidaeEmpididae

OligochaetaTipulidae

OrthocladiinaeDiamesinae

esp Diamesa

(Milner et al., 2001)

Aims 1. To present a novel, alternative glacier river classification

tool (Alpine RIver and Stream Ecosystem = ARISE)

2. To advance hypotheses concerning impact of climate

change on glacierized river system hydrology and

ecology

3. To identify future research imperatives and directions

Alternative glacier river classification (ARISE)

• Previous approaches based mainly on water temperature

• ARISE uses quantified water source contributions

different physicochemical habitat benthic communities

• No quantitative relationships between water source

contributions and stream macroinvertebrates

(Bro

wn

, H

an

nah

& M

iln

er,

2003;

2009)

1. Effect of reduced

meltwater contribution on

community structure?

2. Individual species

response (bioindicators)?

3. How vulnerable is

biodiversity to shrinking

snowpacks and glaciers?

Taillon-Gabiétous basin, Pyrenees

• > decade of research

• 7.7 km2

• 1800-3022 masl

• steep slopes 30-70°

• meadow, above treeline

• 5% permanent snow/ ice

• 2 glaciers

• snowpacks <2700 masl

• karst system

• hillslope/ alluvial aquifers

Spain

France

N

10m

C

A

B

• Water samples:

weekly (high and low flow) at 3 river gauges

monthly samples of groundwater/ hillslope tributaries

snow pits

• EMMA determine water source contributions (Brown, Hannah et al., 2006)

0

100

200

300

400

500

600

700

800

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2

Si (ppm)

SO

42- (

µe

qL

-1)

'Distributed'

'Quickflow'

'Groundwater'

Upper Site

Site A

Site B

Site C

Groundwater Subglacial

distributed

Dilute snow- and ice-melt

0 50

50 50

0

0

100

100

100

Snow

Methods: water sourcing

(Bro

wn

, H

an

na

h &

Mil

ner

, 2

00

9)

A: glacial

B: groundwater

C: confluence

2002 2003

Methods: macroinvertebrates

• 5 0.1m2 Surber samples (250µm

mesh)

• Collected at each site bi-weekly

• Preserved in 4% formalin, then

sorted in the laboratory

• Identification to species level,

where possible

A

B

C

• Meltwater contribution = dilute quickflow + distributed glacial

Proportion meltwater

Proportion meltwater

0

10

20

30

40

50

60

70

0 0.2 0.4 0.6 0.8 1

Ta

xo

no

mic

Ric

hn

ess

(a)

y = -50.35x + 79.89

R = -0.769

1

10

100

1000

10000

100000

0 0.2 0.4 0.6 0.8 1

To

tal A

bu

nd

an

ce

(b)

y = -2.12x + 4.74

R = -0.855

0

5

10

15

20

25

0 0.2 0.4 0.6 0.8 1

No

. E

PT

Ge

ne

ra

(c)

y = -23.25x + 29.93

R = -0.844

Significant increases in:

taxonomic richness

total abundance

mayflies, stoneflies, caddisflies

with decreasing

meltwater contributions

0

20

40

60

80

100

120

140

0 0.2 0.4 0.6 0.8 1

Ab

un

da

nce

(a)

Habroleptoides

berthelemyi

0

50

100

150

200

250

300

350

0 0.2 0.4 0.6 0.8 1

Ab

un

da

nce

(b)

Perla

grandis

0

50

100

150

200

250

300

350

400

0 0.2 0.4 0.6 0.8 1

Ab

un

da

nce

(c)

Rhithrogena

spp.

Proportion meltwater

• Macroinvertebrates as potential indicators of climate change

0

200

400

600

800

1000

1200

0 0.2 0.4 0.6 0.8 1

Ab

un

da

nce

(b)

Diamesa

latitarsis spp.

0

50

100

150

200

250

0 0.2 0.4 0.6 0.8 1

Ab

un

da

nce

(a)

Rhyacophila

angelieri

• Potential loss of endemic species biodiversity and

conservation implications

Proportion meltwater

Response to shrinking glaciers?

In the long term:

• Decreases in meltwater contributions increased

taxonomic richness/ diversity in streams = higher alpha

diversity (within-stream)

But…

• Decreases in meltwater contributions lower habitat

heterogeneity = lower beta diversity (between-stream)

• Local extinction of some species (e.g. Rhyacophila

angelieri) = lower gamma diversity (basin/ region)

Validation in other glacierized basins

Rob Roy, New Zealand

0

50

100

150

200

250

300

350

R1 R2 R3

Mean

ab

un

dan

ce (

ind

ivid

uals

m-2

)

0

50

100

150

200

250

300

R1 R2 R3M

ean

ab

un

dan

ce (

ind

ivid

uals

m-2

) Hydrobiosisspp.

Costachoremaspp.

Nesameletusaustrinus

Zelandoperlaspp.

Zelandobiusspp.

Deleatidiumangustum

Deleatidiumcornutum

0

50

100

R1 R2 R3

Me

an

ab

un

da

nc

e (

ind

ivid

ua

ls m

-2)

Neocupirahudsoni grp.

Hydora spp.

Eukiefferiellaspp.

Mauridiamesaspp.

Diptera & Coleoptera

EPT taxa

Individuals

Validation in other glacierized basins

Kårsavagge, nr. Abisko, Sweden

K1 K2 K4

K3

K5

K6

K7K9

K8

N

Abisko River

B1-B12Watershed

Boun

dary

of A

bisk

oN

atio

nal P

ark

2km

K1 K2 K4

K3

K5

K6

K7K9

K8

N

Abisko River

B1-B12Watershed

Boun

dary

of A

bisk

oN

atio

nal P

ark

K1 K2 K4

K3

K5

K6

K7K9

K8

N

Abisko River

B1-B12Watershed

K1 K2 K4

K3

K5

K6

K7K9

K8

N

Abisko River

K1 K2 K4

K3

K5

K6

K7K9

K8

N

Abisko River

B1-B12Watershed

Boun

dary

of A

bisk

oN

atio

nal P

ark

2km

Validation in other glacierized basins

Kårsavagge, nr. Abisko, Sweden

No

. m

acro

invert

eb

rate

fam

ilie

s

hillslopes/ groundwater

Longitudinal

Lateral

Concluding thoughts and future research

• Integrated, long-term research into the climate-hydrology-

ecology cascade in other glacierized river basins is vital

• Interdisciplinary science is fundamental:

to predict river hydrology and ecology under scenarios

of future climate/ variability

to assess the utility of glacierized river systems as

indicators of global change

to develop conservation strategies for these fragile

ecosystems atmospheric

circulation

local

climate

energy/ mass

exchange

meltwater generation

and drainage

stream flow

contributions(snow, glacier and groundwater)

physico-chemical

habitat

benthic

communities

• ARISE useful tool but requires wider

evaluation

• Shrinking glaciers high, urgent

importance quantify and model

climate-hydrology-ecology links

Acknowledgements

NATURAL

ENVIRONMENT

RESEARCH COUNCIL

ABISKO SCIENTIFIC

RESEARCH STATION

THE ROYAL SWEDISH

ACADEMY OF SCIENCES

Sarah Cadbury

Chris Mellor

Barney Smith

Debbie Snook

Climate-hydrology-ecology interactions

in glacierized river systems

David M. Hannah1, L.E. Brown2 and A. M. Milner1

1School of Geography, Earth and Environmental Sciences,

University of Birmingham, UK. 2School of Geography, University of Leeds, UK.

d.m.hannah@bham.ac.uk