Impacts of acid rain and ozone on vegetation in the Greater Mekong Sub region Lisa Emberson...

Impacts of acid rain and ozone on vegetation in the Greater Mekong Sub region

Lisa Emberson

[email protected]

Patrick Büker, Tim Morrissey, Kevin Hicks, Johan Kuylenstierna, Steve Cinderby, Mike Ashmore, David Simpson, Juha-Pekka

Tuovinen, Mark Zunckel, Miles Sowden, Barabara Badu, Vanessa Walsh

Talk outline

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Why worry about air pollution impacts on vegetation ?

Air pollution risk assessment methods for application in GMS : - Modelling methods

- Experimental methods - Bio-monitoring methods

Application incorporating additional stresses ?- Climate change- Hydrological stress


Stomatal flux/uptake/deposition

Non-stomatal flux/uptake/deposition

External plantsurfaces

Soil

Air pollutantGas, particle, aerosol, solute

Direct

Indirect

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Pollutant Impact mode Impact Scale

Ozone (O3) Direct (stomates) Visible injury, growth & yield reductions, chemical quality

Regional

Sulphur dioxide (SO2)

Direct (stomates & cuticle) Indirect

* Visible injury, growth & yield reductions

Soil acidification (growth & yield reductions)

Local

Regional

Nitrogen oxides (NOx)

Direct (stomates) Indirect

* Growth & yield reductions

Soil acidification (growth & yield reductions)

Local

Regional

Hydrogen Fluorides (HF)

Direct (stomates & cuticle)

Visible injury, growth & yield reductions.Fluorosis in grazing animals

Local

Suspended Particulate Matter (SPM)

Direct **Phytotoxicity, abrasive action, reduced light transmission, occlusion of stomates

Local / Regional

* At low concentrations can stimulate growth via fertilization effect** Dependant upon chemical composition of particles

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Decline of Veitch’s silver fir and maries fir. Japan(courtesy of T. Izuta)


Annual average pH of P

Rodhe et al. 2002

Soil sensitivity to acidic deposition Kuylenstierna et al. 2001

The decrease in soil pH between 1927 to 1982-83 in a beech and spruce forest in southern Sweden (Hallbäcken and Tamm, 1985)

Change in soil pH 1960 – 1994 at Zhurongfeng in S. ChinaDai et al. 1998

Observational evidence of soil acidification in China similar to Europe

No real evidence in other parts of Asia

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O3 injury to rice, Pakistan(courtesy of A. Wahid)


Dentener et al. (2006)

Current surface ozone in 2000

Europe 36.6 ppb ± 4.2United states 38.7 ppb ± 4.9South East Asia 31.5 ppb ± 4.4


CLE2000 – CLE2030Europe +1.8 ± 1.5United states +1.3 ± 2.4South East Asia +3.8 ± 0.7

Δ in surface ozone between 2000 and 2030 current legislation scenario

Talk outline

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Air pollution risk assessment methods for application in GMS : - Modelling methods – Acid Deposition

- Experimental methods - Bio-monitoring methods


What methods exist to estimate risk?

1. Critical Load approach: deposition compared to threshold (CL)

2. Dynamic models – limited application except in China for some sites

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Estimated exceedance of acidification CL of S only (Kuylenstierna et al. 2000)

Exceedance of critical loads a static expression of risk but is it real?

time dimension issue: acidification has not occurred for long enough for clear impacts to be seen?

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“Serious acidification effects not likely to occur in next few decades in Asia except in China”

Henning Rodhe

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Estimates time development of acidification as a function of continued acidic deposition and variation in soil sensitivity over time

Hicks et al. in prep

Talk outline

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Air pollution risk assessment methods for application in GMS : - Modelling methods

- Experimental methods – surface ozone - Bio-monitoring methods


Response

Dose

Assessing O3 impacts to species/ cultivars

Experimental Methods

• individual pollutants & pollutant combinations• establish dose response relationships• pollutant interactions with other stresses

Controlled exposure

• Free Air Concentration Enrichment (FACE)• Temporary chambers• Open Top Chambers• Solardomes• Indoor fumigation chambers / glasshouses

Distu

rban

ce

Response

Dose

YieldNutritional qualityVisible injury

ConcentrationFlux


* Annual mean * 7hr annual mean* 7hr growing season mean * AOT40

(53 ppb)

Ozone characterization indices

0

20

40

60

80

100

0 50 100 150 200 250 300 350

Year day

Ozo

ne

co

nc

(pp

b)

0

2000

4000

6000

8000

10000

12000

AO

T4

0 (

pp

b.h

rs)

Growing season

7 hr mean dose response relationships for different species including rice

cf. Wang & Mauzerall 2004

AOT40 relationship with wheat (Triticum aestivum) grain yield

• Most robust AOT40 relationship • 17 experiments, 6 countries, 10 growing seasons, 10 cultivars• Critical Level : AOT40 of 3, 000 ppb.h. corresponding to 5% yield loss (99% confidence) calculated over a 3 month growing period

(Fuhrer, 1996)

Talk outline

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Air pollution risk assessment methods for application in GMS : - Experimental methods

- Modelling methods – surface ozone- Bio-monitoring methods


How can we estimate air pollution impacts?

Dose-Response Relationships

Modelling methods

3 month AOT40 simulations calculated with the MATCH model

Engardt pers. comm., Emberson et al. in press

BUT

Are these areas identified as being at risk from ground level ozone correct?

How good is the provisional risk assessment modelling?

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Modelling methods

How good is the regional ozone concentration data?

What are the receptors most at risk?

How well can AQGs protect local species and varieties?

Modelling methods

Talk outline

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- Modelling methods- Bio-monitoring methods – surface ozone


Bio-monitoring

Bio-monitoring and Chemical Protectant Studies

• Established bio-indicator in Europe and North America

• Sensitive and resistant clones so can assess magnitude of air pollution impacts on visible injury & biomass.

Buse et al. 2002/2003

Bio-monitoring and Chemical Protectant Studies

Structural formula for N-(2-(2-oxo-1-imadazolidinyl)ethyl)-N’-phenylurea

abbreviated as EDU for ethylenediurea

EDU suppresses acute and chronic ozone injury on a variety of plants under ambient O3 conditions (Godzik & Manning, 1998)

Pakistan soybean cv. NARC-1 showing protective effect of EDU at a roadside rural site in Lahore,

Pakistan (photo courtesy of A. Wahid)

Bio-monitoring

Bio-monitoring

All Bio-monitoring sites:• Microloggers for ToC & RH % (30 min)• Ozone passive samplers (2 week)

At select sites:• Solar radiation, photosynthetically active radiation (PAR)• Continuous ozone monitoring (hourly) • Soil water content

• Plant physiological parameterse.g. Photosynthesis, stomatal conductance, leaf area index, biochemical analysis (e.g. heavy metals, protein content….)

Bio-monitoring

Europe & North America

South AsiaSouthern Africa

Provisional Risk AssessmentClover clone bio-monitoring

EDU chemical protectant study WheatMung bean

e.g. Maizestaple Pulse

6 sites 5 sites

India, Pakistan, Sri Lanka, Bangladesh, Nepal

South Africa, Botswana, Zimbabwe, Mozambique

Zambia, Tanzania

RAPIDC Project funded by Sida“Regional Air Pollution in Developing Countries”

How good is the regional ozone concentration data?Passive samplers, O3 monitors

What are the receptors most at risk?Local agricultural expertise

How well can AQGs protect local species and varieties?Bio-monitoring evaluation of damage occurring within and outside provisionally assessed risk areas

Bio-monitoring

• Species type / cultivar

ClimatePrecipitation patternsSunshine hoursHigher temperaturesAtmospheric humiditySoil Moisture deficit

Vegetation sensitivityCropping patterns (growing season)Pollutant dispersionO3 formation

• Agronomic practicesIrrigationFertilizerBreeding programmes (selecting increased / reduced crop sensitivity)

Flux

Dose modifiers

Modelling methods

Surface Resistance Rsur

AOTx“Concentration”

AFstY“Flux”


The Air Pollution Crop Effect (APCEN) network

1. Advise on methodological development

2. To capacity build in the regions –provide technical support to the bio-monitoring campaigns

3. To help in translation of science to policy

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RAPIDCRegional air pollution in developing countries

Bio-monitoring

The APCEN Network

Region Network Members

Countries / regions represented

Africa8

Egypt, Kenya, Mozambique, South Africa, Zimbabwe

Asia

43India, Japan, Nepal, Pakistan, P.R. China,

Philippines, South Korea, Sri Lanka, Taiwan, Thailand

The Americas, Europe and Australia

16 Australia, Chile, Sweden, UK, USA

The APCEN network

2nd APCEN workshop held in Stellenbosch, South Africa 2006

Talk outline

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- Modelling methods- Bio-monitoring methods



Why worry about surface ozone concentrations ?

Δ in surface ozone between 2030clim change and 2030 current legislation scenario and projected 2030 climate

South East Asia CLE2030c – CLE2030-0.2 ± 0.6

Fuhrer et al. 2005

Morgan et al. 2006

• FACE soybean (glycine max) experiment

• Increased O3 concentrations over two growing seasons by 23 % - mimicking projections for 2050

• Resulted in 20% loss in seed yield

• Results suggest even greater losses than those previously predicted by closed chamber studies

O3

O3

Rsto = 1/ (gmax * fphen * flight * max {fmin, (ftemp * fVPD * fSWP)})

Generic glight function

0

0.2

0.4

0.6

0.8

1

0 500 1000 1500 2000Irradiance (umol m-2 s-1 PAR)

Rel

ativ

e g

glight = 1 - exp (- * PAR)

Generic gage function

0

0.2

0.4

0.6

0.8

1

1.2

0 100 200 300

Year day

Rel

ativ

e g

gage_b gage_c

gage_a

Generic gtemp function

0

0.2

0.4

0.6

0.8

1

10 15 20 25 30 35 40Temperature (oC)

Rel

ativ

e g

T_optT_min T_max

Generic gVPD function

0

0.2

0.4

0.6

0.8

1

0 1 2 3 4 5

VPD (kPa)

Rel

ativ

e g

VPD_max VPD_min

Generic gSWP functions

0

0.2

0.4

0.6

0.8

1

-2 -1.5 -1 -0.5 0

Soil water potential (MPa)

Rel

ativ

e g

SWP_max SWP_min

Gmax mmol O3 m-2 s-1 * Phenology

PAR

SMDVPD

ToC

Talk outline

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- Modelling methods- Bio-monitoring methods


-1000.00 0.00 1000.00 2000.00 3000.00

-5000.00

-4000.00

-3000.00

-2000.00

-1000.00

0.00

1000.00

0 1000 2000 3000 4000

4 0

6 0

8 0

1 0 0

Zunckel et al 2004

Modelled ozone concentrations across Southern Africa

Future applications ?

Growing season length and risk of drought in southern Africa

Future applications ?

PEt & AEtf(Ra, Rb, Rsto)VPD & Net radiation

P Ei

Soil water

PEt : AEtR

elative yield

Drought related yield losses

O3 related yield losses

Compare ozone and drought stress to maize across region

Conclusions

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Acid deposition may be a problem in the future in parts of south east Asia

O3 is likely to be already causing damage to crops and forests in the GMS ?

O3 concentrations are projected to increase relatively rapidly over the next 20 to 50 years in this region

As such, there is an urgent need to develop methods for O3 risk assessment for the GMS region :

These methods can be founded on existing experimental and modelling techniques which would ideally be supported by bio-monitoring evaluation

In addition, methodological selection and development should ensure assessments can incorporate additional stresses such as climate change and hydrological related stresses

This research is supported by Sida and Defra

Acknowledgements

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Related projects are also supported by the EU and START PACOM.

Impacts of acid rain and ozone on vegetation in the Greater Mekong Sub region Lisa Emberson...

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