Climate-hydrology-ecology interactions in glacierized river systems. Presented by David Hannah at the "Perth II: Global Change and the World's Mountains" conference in Perth, Scotland in September 2010.

1. 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

2. Shrinking glaciers
(Dyurgerov & Meier, 2005)
• Growing evidence indicates glaciers shrinking
• Glacierized basins highly sensitive (most vulnerable) to
climate change

3. atmospheric local energy/ mass
circulation climate exchange
meltwater generation stream flow
and drainage contributions
(snow, glacier and groundwater)
physico-chemical
habitat
benthic
communities

4. 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
(Milner, Brown & Hannah, 2009)

5. Ecological response?
High Chloroperlidae
Leptophlebiidae (NZ)
Nemouridae
Leuctridae
Heptageniidae
Rhyacophilidae
Chironominae
Limnephilidae
Perlodidae
Taenioplerygidae
Baetidae
Simuliidae
Empididae
Oligochaeta
Tipulidae
Diamesinae Orthocladiinae
esp Diamesa
Low (Milner et al., 2001)
0 2 4 6 8 10
Water temperature (T max)

6. 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

7. 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
(Brown, Hannah & Milner, 2003; 2009)
contributions and stream macroinvertebrates
1. Effect of reduced
meltwater contribution on
community structure?
2. Individual species
response (bioindicators)?
3. How vulnerable is
biodiversity to shrinking
snowpacks and glaciers?

8. Taillon-Gabiétous basin, Pyrenees
• > decade of research France
• 7.7 km2 Spain
• 1800-3022 masl
• steep slopes 30-70°
• meadow, above treeline
• 5% permanent snow/ ice
• 2 glaciers
• snowpacks <2700 masl
• karst system
• hillslope/ alluvial aquifers

9. N
A
10m
B
C

10. Methods: water sourcing
800 'Distributed'
'Quickflow'
700 0
'Groundwater' 100
600 Upper Site
Site A
SO4 (µeqL )
500 Site B
-1
Site C Subglacial
400 Groundwater
50 distributed
2-
50
300
200
100
100
0
0
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 100 50 0
Dilute snow- and ice-melt
Si (ppm)
Snow
• 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)

11. 2002 2003
A: glacial
B: groundwater
(Brown, Hannah & Milner, 2009)
C: confluence

12. 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

13. A
B
C
• Meltwater contribution = dilute quickflow + distributed glacial

14. (c) 25
(a)
70
60 20
Taxonomic Richness
No. EPT Genera
50
15
40
30 10
20
5
y = -50.35x + 79.89 y = -23.25x + 29.93
10
R = -0.769 R = -0.844
0 0
(b) 100000 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1
Proportion meltwater
10000
Total Abundance
Significant increases in:
1000
100 taxonomic richness
10
y = -2.12x + 4.74
total abundance
1
R = -0.855 mayflies, stoneflies, caddisflies
0 0.2 0.4 0.6 0.8 1
Proportion meltwater with decreasing
meltwater contributions

15. • Macroinvertebrates as potential indicators of climate change
(a)
140
120
100
Habroleptoides
Abundance 80 berthelemyi
60
40
20
(b)
0
350 0 0.2 0.4 0.6 0.8 1
300
250 Perla
Abundance
200
grandis
150
100
50
0
(c)
400 0 0.2 0.4 0.6 0.8 1
350
300 Rhithrogena
Abundance
250
200 spp.
150
100
50
0
0 0.2 0.4 0.6 0.8 1
Proportion meltwater

16. (b)
1200
1000 Diamesa
latitarsis spp.
Abundance
800
600
400
200
0
(a) 0 0.2 0.4 0.6 0.8 1
250
200
Rhyacophila
Abundance
150 angelieri
100
50
0
0 0.2 0.4 0.6 0.8 1
Proportion meltwater
• Potential loss of endemic species  biodiversity and
conservation implications

17. 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)

18. Validation in other glacierized basins
350
Rob Roy, New Zealand
Mean abundance (individuals m )
-2
300 Individuals
250
200
150
100
50
0
300 R1 R2 R3 Hydrobiosis
Mean abundance (individuals m )
-2
250
EPT taxa spp.
Costachorema
spp.
200 Nesameletus
austrinus
Zelandoperla
150 spp.
Zelandobius
100 spp.
Deleatidium
angustum
50
Deleatidium
cornutum
0
100 R1 R2 R3
Mean abundance (individuals m )
Diptera & Coleoptera
-2
Neocupira
hudsoni grp.
Hydora spp.
50
Eukiefferiella
spp.
Mauridiamesa
spp.
0
R1 R2 R3

19. Validation in other glacierized basins
Kårsavagge, nr. Abisko, Sweden
Watershed
ark
B1-B12
al P
ion
Nat
sko
Abi
K3
f
ry o
K1
nda
K2 K4
Bou
K5 K7 K8
K6 K9
N
2km
Abisko River

20. Validation in other glacierized basins
Kårsavagge, nr. Abisko, Sweden
Longitudinal
No. macroinvertebrate families
Lateral
hillslopes/ groundwater

21. 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
• ARISE useful tool but requires wider
evaluation meltwater generation
and drainage
stream flow
contributions
(snow, glacier and groundwater)
• Shrinking glaciers  high, urgent physico-chemical
habitat
importance  quantify and model
climate-hydrology-ecology links benthic
communities

22. Acknowledgements
NATURAL
ENVIRONMENT
RESEARCH COUNCIL
ABISKO SCIENTIFIC
RESEARCH STATION
THE ROYAL SWEDISH
ACADEMY OF SCIENCES
Sarah Cadbury
Chris Mellor
Barney Smith
Debbie Snook

23. 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