Climate change and land-use interactions affect aquatic ...net.fafu.edu.cn/_upload/article/files/22/39/90917c...Climate change and land-use interactions affect aquatic ecosystems Dr

Climate change and land-use interactions affect

aquatic ecosystems

Dr. John Richardson

FAFU

courses.forestry.ubc.ca/frst386/

“Rivers in some of the world’s most populous regions

are losing water, ...”

"The distribution of the world's fresh water, already an important

topic," says Cliff Jacobs of NSF's Division of Atmospheric Sciences,

"will occupy front and center stage for years to come in developing

adaptation strategies to a changing climate.”

Of rivers examined, more than 70% were decreasing (period

1948 to 2004)

Including: Yellow River (China), Ganges (India), Niger (west

Africa), Colorado (SW USA)

Rivers that were increasing were largely northern rivers,

increased by glacier melt

Appear to be related to climate change (consistent with all

predictions, but of course there is no way to test this directly)

NSF – National Science Foundation (USA)

Predictions about

climate

Consequences from

different aspects of

climate change

Responses of aquatic

systems

Outline

photo: courtesy Dr. Mark Wipfli, U of Alaska

Source: US Geological Service (USGS)

Surface water is ~0.009% of total

http://www.metoffice.com/research/hadleycentre/models/modeldata.html

Change in annual average surface air temperature from

1960-1990 to 2070-2100 from HadCM2 IS92a

Hadley Centre for Climate Prediction and Research, the Met. Office, UK

Change in June-July-August average surface air temperature

from 1960-1990 to 2070-2100 from HadCM2 IS92a

Hadley Centre for Climate Prediction and Research, UK

Change in annual average precipitation from

1960-1990 to 2070-2100 from HadCM2 IS92a


Change in June-July-August average precipitation from

1960-1990 to 2070-2100 from HadCM2 IS92a


Change in annual average soil moisture content from

1960-1990 to 2070-2100 from HadCM2 IS92a


Change in June-July-August average soil moisture content

from 1960-1990 to 2070-2100 from HadCM2 IS92a


Biggest effect on aquatic resources will likely be in summer

http://www.metoffice.gov.uk/research/hadleycentre/pubs/brochures/2005/clim_green/slide32.pdf

Predicted change in global river flow between present day and the

late 21st century for SRES emissions scenario A1B


Potential impacts on:

Flows (averages, peaks, lows)

Timing of flows

Temperatures

Water quality (pH, nutrients, etc.)

Quality of organic matter

Timing of life cycle events

20th century was the wettest century in the past 1000 years!

Transpiration

Interaction of vegetation in H2O cycle

Evaporation

~98% of water taken up by roots is lost by transpiration through leaf stomata

e.g. 15 m high Silver Maple (Acer saccharinum) can loose 220 litres

water per hour through transpiration

↓ stomatal conductance →

↓ transpiration

↑ soil moisture & runoff


Transpiration

Surface

evaporation

Surface runoff

Subsurface runoff Infiltration

Precipitation

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

0 100 200 300 400 500 600

CO2 concentration inside leaf (ppmv)

Sto

ma

tal co

nd

ucta

nce

(m

/s)

↑ [CO2] → ↓ stomatal conductance Plant response to [CO2] –

physiological forcing stomatal conductance


Projected global average river flow with & without CO2 effect on plants business-as-usual scenario


Projected changes in river flow with & without CO2 effects on plants average 2071-2100 minus 1971-2000


Some predicted consequences of climate change for aquatic systems

Summers: warmer temperatures,

less rainfall, & higher evapo-

transpiration less water for

aquatic environments (unless

reduction in evapotranspiration is

sufficient due to increased CO2)

Headwater streams will be most

impacted by changes (and made

worse by water extraction from

groundwater, i.e., wells)

Winters: warmer winters mean less

storage as snow, so less available

during summer

Some consequences of climate change for aquatic systems

The minimal water flows, and not

the averages, are the impacts

that are most difficult to plan for,

and the most damaging for

aquatic ecosystems

More dams and greater extraction

– less water in lakes, reservoirs

and rivers

Warmer water and higher

concentrations of contaminants

Carnation Creek, BC

“Water for Life” – United Nations International

Decade for Action – 2005 – 2015

Over-

exploitation Water

pollution

Habitat

degradation

Flow

modification

Species

invasion

Dudgeon, D. et al. 2006. Freshwater biodiversity: importance, threats, status

and conservation challenges. Biological Reviews 81: 163-186.

World Resources Institute

Hu

ma

n w

ate

r

se

cu

rity

th

rea

t

Th

rea

t to

bio

div

ers

ity

Vörösmarty CJ et al. 2010. Global threats to human water security and river biodiversity. Nature 467:555-561.

Vörösmarty CJ et al. 2010. Global threats to human water security and river biodiversity. Nature 467:555-561.

High Low

Low

High

Human water

security threat

Threat to

biodiversity

Threats – Increasing need for power – more dams?

Water crisis closes Tofino businesses

Resort town is forced to ration drinking water, turn away visitors

Vancouver Sun, 30 August 2006

Headline

http://www.metoffice.gov.uk/research/hadleycentre/pubs/brochures/2005/clim_green/slide33.pdf

Schindler, DW & WF Donahue. 2006. An impending water crisis in Canada’s western

prairie provinces. Proceedings of the National Academy of Sciences 103: 7210-7216.

0 500 1000

km

Canada

Rocky Mountains

Pacific

Ocean

Prairies

Using up “fossil” water

Greig HS, Kratina P, Thompson PL, Palen WJ, Richardson JS & Shurin JB.

2012. Warming, eutrophication, and predator loss amplify subsidies between

aquatic and terrestrial ecosystems. Global Change Biology 18: 504–514.

+ 3°C warming year-round

+ or – Three-spined Sticklebacks

Ambient or increased nutrients (N, P) Complex outcomes!

Hogg I.D. & Williams D.D. 1996. Response of stream invertebrates to a global-warming

thermal regime: An ecosystem-level manipulation. Ecology 77: 395-407.

control





Adult sizes of Nemoura trispinosa

(Plecoptera – stoneflies)

Emergence timing of adults of the

caddisfly Lepidostoma vernale

Kominoski, J.S. et al. 2007. Elevated CO2 alters

leaf-litter-derived dissolved organic carbon:

effects on stream periphyton and crayfish

feeding preference. Journal of the North

American Benthological Society 26: 663-672.

p = 0.02

3 7 12 25 35

Sampling day

p < 0.05 Ambient

Elevated

25

20

15

10

5

0

Bio

volu

me

(mm

3/c

m2 x

10

3)

1.5

1.0

0.5

0 Ch

l a (

µg/c

m2)

DOC from poplar

leaves grown under

ambient CO2 levels, or

2x ambient (720 ppm)

DOC from leaves grown under elevated

[CO2 ] had molecules that were harder to

break down, and therefore contributed less

to biofilm (periphyton) development

Kominoski, J.S. et al. 2007. Elevated CO2 alters leaf-litter-derived dissolved organic

carbon: effects on stream periphyton and crayfish feeding preference. Journal of the North

American Benthological Society 26: 663-672.

p < 0.05

Ambient Elevated

Tim

e (

s)

300

200

100

0

Crayfish Number

1 2 3 4 5 6 7 8 9 10 11

Crayfish preferred periphyton (biofilm)

produced with ambient DOC (from poplar

leaves) over DOC from leaves grown at 2X

CO2 concentrations

Hari, R.E. et al. 2006. Consequences of climatic change for water temperature and brown

trout populations in Alpine rivers and streams. Global Change Biology 12: 10-26.

North American

Water and Power

Alliance

(NAWAPA) –

Ralph M. Parsons

Company,

California

For additional reading, see Nature – 20 March 2008

Perhaps increased trade in “virtual water” instead

Summary

Many dimensions to changes in climate:

temperature, rainfall, CO2, food quality, less

storage as snow, seasonality, …

Some consequences: higher peak flows, lower

summer flows, warmer summer temperatures

A great deal of uncertainty, however, all

predictions are for change, and most changes

will be difficult to deal with

These changes will result in more and more

emphasis on forest management to protect

water yield, habitat quality, temperatures, and

water quality

Documents

Climate change and land-use interactions affect aquatic ...net.fafu.edu.cn/_upload/article/files/22/39/90917c...Climate change and land-use interactions affect aquatic ecosystems Dr