David Stone, IPILPS Workshop ANSTO 18-22 April 2005 Diurnal Cycle Observations of Stable Water Isotopes in the Biosphere.

David Stone, IPILPS Workshop

ANSTO 18-22 April 2005

Diurnal Cycle Observations of Stable Water Isotopes in the

Biosphere

IPILPS: isotopes at the land surfaceIPILPS: isotopes at the land surface

Scientific HypothesisObservation and analysis of the diurnal fluxes of H2

18O and HDO between the soil, plants and atmosphere can accurately determine the partitioning of precipitation into transpiration, evaporation and total runoff.

MethodThree ecosystems were selected as study areas

Tropical forest, such as the Amazon Basin, Sth America

Cool, humid temperate forest, such as Central Europe, or Nth America

Warm, dry temperate forest, such as SE Australia

Exploit stable water isotopes H218O and HDO to investigate the hypothesis.

Observations would be required at Tumbarumba

Field data expected to be available for the Amazon, Europe and America

IPILPS Stable Isotope data needsIPILPS Stable Isotope data needs Data expected to be available include

precipitation atmospheric vapour plant (stem and leaf) water soilwater groundwater ( not expected to vary significantly) riverwater

The data will be used within IPILPS to evaluate isotope enabled LSS output:

Overview of presentationOverview of presentation

• Expected ranges of values the precipitation input at the three ecosystems vapour<stem<leaf order of enrichment

• Data sets examined Amazon; Manaus, Santarem and Trinidad Central Europe; Munich, other German sites North America; temperate and semi-arid others

THE WATER CYCLE

Variation in del 18O (‰)

O18

O18

Leafwater 3 to10 ‰

GMW

L

LEL

Local vapour

Root zone water= stem water

= transpired water

Surface water

Surface evaporate

rainwater

9-10 ‰9-10 ‰

Expected isotope ratios for SE Australia (Tumbarumba)Expected isotope ratios for SE Australia (Tumbarumba)

9-10 ‰9-10 ‰

LeavesLeaves

Vapor Samples, ANSTO, 8 Dec 2004

0

10

20

30

40

50

60

-16 -14 -12 -10 -8 -6 -4 -2 0

del O-18

heig

ht

(m)

10am, 25C

5pm, 20CMean rainfallMean rainfall

10 ‰ depletion10 ‰ depletion

Precipitation Input Signal; 3 sitesPrecipitation Input Signal; 3 sites

Munich Vapour and PrecipitationMunich Vapour and Precipitation

Vapour and precipitation lie along a single MWLVapour and precipitation lie along a single MWL

data source: W. Stichler, unpublished

Munich; vapour/precipitation equilibriumMunich; vapour/precipitation equilibrium

Regression; r2 = 0.7

Delta 18O(p-v) = 8.5 ‰

Regression; r2 = 0.7

Delta 18O(p-v) = 8.5 ‰

data source: W. Stichler, unpublished

IPILPS data requirements and sourcesIPILPS data requirements and sources

• Water isotopologues del H2

18O and 1H2H16O (‰) both desired

• Comparison of LSS By output, and against real data

• Real field data required at appropriate time scales, monthly, daily, hourly

• Prefer data at diurnal timescale• BASIN database; (Ehleringer), Americas• CarboEuroflux; (various), Europe

Data collection methodsData collection methods

• Towers fitted with tubing for cryogenic vapour trapping, water kept frozen

• Soil and Leaf samples sealed in exetainers; distilled cryogenically before analysis

• del D and del O-18 performed by IR-MS

Tropical Rainforest data; Manaus, AmazonTropical Rainforest data; Manaus, Amazon

LBA BASIN sites

LBA BASIN sites

ManausManaus

SantaremSantarem

TrinidadTrinidad

10‰ enrichment10‰ enrichment

data source: Matsui et al,1983, Acta Amazonica, 13, 307-68

0

10

20

30

-20 -16 -12 -8 -4 0 4 8 12 16 2018 O

Hei

ght(

m)

Leaf water Stem water

Manaus Forest - Mar 99

10.4 ‰ average enrichment10.4 ‰ average enrichment

amam pmpm

0

10

20

30

40

50

-20 -16 -12 -8 -4 0 4 8 12 16 2018 O

Hei

ght (m

)

Leaf water Stem water Water vapour

Manaus Forest - May 99Data source: LBAdatabase (Ometto); submitted for publication

Canopy Leaves enrichedCanopy Leaves enriched

Understory Leaves less enrichedUnderstory Leaves less enriched

Enrichment increases during dayEnrichment increases during day

11 ‰11 ‰

9 ‰9 ‰

0

10

20

30

40

50

-20 -16 -12 -8 -4 0 4 8 12 16 2018 O

Heig

ht (m

)

Leaf water Stem water Water vapour

Manaus Forest - May 99

0

10

20

30

40

50

-20 -16 -12 -8 -4 0 4 8 12 16 20

18 O

Heig

ht (m

)

Leaf water Stem water Water vapour

Manaus Forest - Oct 99

9 ‰9 ‰

11 ‰11 ‰

Data source: LBA (Ometto); unpublished

Dry season vapour, leaf and stem water more enrichedDry season vapour, leaf and stem water more enriched

7 ‰7 ‰11 ‰11 ‰

0

10

20

30

40

50

-20 -16 -12 -8 -4 0 4 8 12 16 20

18 O

Hei

ght (m

)

Leaf water Stem water Water vapour Understory Leaf Water

Manaus Forest - Feb. 00

0

10

20

30

-20 -16 -12 -8 -4 0 4 8 12 16 2018 O

Hei

ght(

m)

Leaf water Stem water

Manaus Forest - Mar 99

12- 14 ‰12- 14 ‰

6 ‰6 ‰

Data source: LBA (Ometto); unpublished

Inter-annual differences possible?Inter-annual differences possible?

Much less leaf enrichment than in previous year

Much less leaf enrichment than in previous year

11 ‰11 ‰

0

5

10

15

20

25

30

-20 -15 -10 -5 0 5 10 15 2018 O

Hei

ght (m

)

Leaf water Stem water Water vapour

Santarem Forest - May 99

0

5

10

15

20

25

30

-20 -15 -10 -5 0 5 10 15 20

18 O

Hei

ght (m

)

Leaf water Stem water

Santarem Forest - Mar 99

10- 12 ‰10- 12 ‰

8 ‰8 ‰

Data source: LBA (Ometto); unpublished

8 ‰8 ‰

0

5

10

15

20

25

30

-20 -15 -10 -5 0 5 10 15 20

18 O

Heig

ht (m

)

Leaf water Stem water Water vapour Leaf understory

Santarem Forest - Feb 00

0

5

10

15

20

25

30

-20 -15 -10 -5 0 5 10 15 20

18 O

Hei

ght (m

)

Leaf water Stem water Water vapour

Santarem Forest - Oct 99

10- 13 ‰10- 13 ‰

5 ‰5 ‰

Data source: LBA (Ometto); unpublished

10 ‰10 ‰

9 ‰9 ‰ Much less leaf enrichment than in previous year

Much less leaf enrichment than in previous year

Dry season vapour, leaf and stem water more enrichedDry season vapour, leaf and stem water more enriched

0

10

20

30

40

50

-20 -16 -12 -8 -4 0 4 8 12 16 2018 O

Hei

ght (m

)

900A 1050A 1210P 155P 250P

Manaus Forest water vapor - J un_00

0

10

20

30

-20 -16 -12 -8 -4 0 4 8 12 16 2018 O

Heig

ht (m

)

Leaf water Stem water

Manaus Forest - J un_00

Data source: LBA (Ometto); unpublished

Vapour less enriched mid-morning, but more enriched in afternoon

Vapour less enriched mid-morning, but more enriched in afternoon

5 ‰ difference in canopy5 ‰ difference in canopy

12 ‰12 ‰

8 ‰8 ‰

0

10

20

30

40

50

-20 -16 -12 -8 -4 0 4 8 12 16 2018 O

Hei

ght (m

)

1100A 1225P 1325P 200P

Santarem Forest water vapor - J un_00

0

10

20

30

40

50

-20 -16 -12 -8 -4 0 4 8 12 16 20

18 O

Heig

ht (m

)

Leaf water Liana_leaves Liana_stem Stem water

Santarem Forest - J un_00Data source: LBA (Ometto); unpublished

Vapour more enriched midday, but less enriched in afternoon

Vapour more enriched midday, but less enriched in afternoon

5-10 ‰ difference in canopy5-10 ‰ difference in canopy

12 ‰12 ‰

8 ‰8 ‰

small difference between vapour and stems!!

small difference between vapour and stems!!

-20.00

-15.00

-10.00

-5.00

0.00

600 800 1000 1200 1400 1600 1800time

del O

-18

0.2 metres

22 metres

42 metres

Manaus Forest - J un_00

-20.00

-15.00

-10.00

-5.00

0.00

5.00

600 800 1000 1200 1400 1600 1800time

del O

-18

0.2 metres

21 metres

45 metres

Santarem Forest - J un_00

Amazon Forest Vapour daytime variation, June 2000Amazon Forest Vapour daytime variation, June 2000

Data source: LBA (Ometto); unpublished

Vapour more enriched midday, but less enriched in afternoonVapour more enriched midday, but less enriched in afternoon

Vapour less enriched mid-morning, but more enriched in afternoonVapour less enriched mid-morning, but more enriched in afternoon

Data source: Leo Sternberg, IAEA 2004Data source: Leo Sternberg, IAEA 2004

Amazon Forest Vapour Keeling Plot analysis, June 1995Amazon Forest Vapour Keeling Plot analysis, June 1995

Data source: Leo Sternberg, IAEA 2004Data source: Leo Sternberg, IAEA 2004

Amazon Forest Vapour Keeling Plot analysis, May - Dec 1995Amazon Forest Vapour Keeling Plot analysis, May - Dec 1995

Diurnal leaf vapour and water del 18-O, Trinidad; Aug 1995

-25

-20

-15

-10

-5

0

5

10

15

20

25

6:00 8:00 10:00 12:00 14:00 16:00

time of day

del 1

8-O

transpired vapour day 1

transpired vapour day 2

leaf water (day 1)

leaf water (day 2)

Atmos Vapour (day 1)

Atmos Vapour (day 2)

Poly. (transpired vapourday 1)Poly. (leaf water (day 1))

Poly. (Atmos Vapour(day 1))

data source: Harwood et al. 1998, Plant, Cell, And Environment 21:269-283

Average precip, calcAverage precip, calc

ConclusionsConclusions

• AmazonLeaf enrichment increases during day

Canopy Leaves enriched, understory much less so

Stem water enriches slightly in dry season

Dry season vapour, leaf & stem water more enriched

Vapour<Stem<Leaf enrichment close to optimum

Keeling plot analysis, 18O, indicates transpiration

predominant flux of return vapour to atmosphere

Cool Temperate; Munich, GermanyCool Temperate; Munich, Germany

CarboEuroFlux sitesCarboEuroFlux sites

Jena and DresdenJena and Dresden

data source: W. Stichler, unpublished

data source: W. Stichler, unpublished

data source: W. Stichler, unpublished

Munich Vapour and PrecipitationMunich Vapour and Precipitation

data source: W. Stichler, unpublished

Hainich Germany, Beech Forest (2001-2, Euro)

-12

-10

-8

-6

-4

-2

0

2

9:36 12:00 14:24 16:48 19:12 21:36 0:00

time of day

del 1

8-O

Soil water

Stem water

Leaf water

Roots

Litter

data source: website: CARBOEUROFLUX

Average precip, calc

Leaf water depletes overnightLeaf water depletes overnight

Samples taken in evening 19:00-23:00Samples taken in evening 19:00-23:00

Stem and soilwater: little variationStem and soilwater: little variation

Hainich (Jena) Germany, Beech Forest (Jul-Aug 2001)

-12

-10

-8

-6

-4

-2

0

2

19/04/01 28/07/01 5/11/01 13/02/02 24/05/02 1/09/02 10/12/02date

del 1

8-O

Soil water

Stem water

Leaf water

Roots

Litter

data source: website: CARBOEUROFLUX

Average precip, calc

Leaf water depletes summer to winterLeaf water depletes summer to winter

Stem and soilwater show little variationStem and soilwater show little variation

Tharandt (Dresden) Germany, Beech Forest (Jul-Aug 2001)

-15

-10

-5

0

5

10

15

20

8/06/01 28/07/01 16/09/01 5/11/01 25/12/01 13/02/02 4/04/02 24/05/02 13/07/02 1/09/02 21/10/02 10/12/02

date

del 1

8-O

Soil water

Stem water

Leaf water

data source: website: CARBOEUROFLUX

Average precip, calc

Leaf water depletes summer to winterLeaf water depletes summer to winter

Stem and soilwater show little variationStem and soilwater show little variation

Cool Temperate; Ottawa and OregonCool Temperate; Ottawa and OregonBASIN sitesBASIN sites

Oregon sitesOregon sitesOttawaOttawa

OklahomaOklahoma

ArizonaArizona

Ottawa Pine Forest, Flanagan 1993; Stem and Leaf

-20

-15

-10

-5

0

5

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00

time of day

del 1

8-O

Leafwater

StemWater

data source: Flanagan, L.B. and Varney, G.T. 1995, Oecologia 101:37-44

10 ‰ enrichment10 ‰ enrichment

Oregon Pine forest, (Cascade), mid-canopy vapour, Aug 1997

-20.00

-15.00

-10.00

-5.00

0.00

5.00

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00

time of day

de

l 18

-O

VapourLeafwaterStemWaterSoilwaterPoly. (Vapour)Poly. (Leafwater)

data source: D. Bowling unpublished observations

Average precip, calcAverage precip, calc

Leafwater enriched during daytimeLeafwater enriched during daytime

10 ‰ enrichment10 ‰ enrichment

Oregon Pine forest (Metolius), mid-canopy vapour; Aug 1997

-20.00

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

20.00

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00

time of day

del

18-

O

VapourLeafwaterStemWaterSoilwaterPoly. (Vapour)Poly. (Leafwater)

Source: D. Bowling et al., 2002. Oecologia 131:113-124 and unpublished observations

latitude: 44° 30´ Nlongitude:121° 37´ Welevation: 941 m

Average precip, calcAverage precip, calc

Oregon (Sisters) Pine forest, mid-canopy vapour; Aug 1997

-20.00

-15.00

-10.00

-5.00

0.00

5.00

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00

time of day

del

18-O

VapourLeafwaterStemWaterSoilwaterPoly. (Vapour)Poly. (Leafwater)

data source:D. Bowling unpublished observations

latitude: 44° 18´ Nlongitude:121° 20´ Welevation: 930 mAverage precip, calcAverage precip, calc

Shallow soilwaterShallow soilwater

deeper soilwaterdeeper soilwater

Oklahoma Prairie grass (2000, Riley etal)

-15

-10

-5

0

5

10

15

20

4-May-00 14-May-00 24-May-00 3-Jun-00 13-Jun-00 23-Jun-00 3-Jul-00 13-Jul-00 23-Jul-00 2-Aug-00

date

del

18-

O

Soil water

Stem water

Leaf water

Vapour

0-2.5cm

2.5-5cm

5-10cm

5-10cm

5-10cm

0-2.5cm

0-2.5cm

2.5-5cm

10-20cm

10-20cm

data source: Global Change Biology, (2003) 9, 1567-1581

Average precip, calcAverage precip, calc

13 ‰ enrichment13 ‰ enrichment

ConclusionsConclusions

• EuropeLeaf enrichment decreases during evening (6-11pm)Stem, roots, soil and litter show small variations, but

little systematic seasonal changeVapour<Stem<Leaf enrichment less than optimum

• Humid North America Soilwater data have a large variationForest stem<leaf enrichment at optimum Grassland stem<leaf enrichment at optimumForest and Grassland vapour<stem enrichment less than

optimum ( Summer data only available)

Warm Temperate - semi arid regions; Warm Temperate - semi arid regions; Israel, ArizonaIsrael, Arizona

ISRAEL; expected del O-18, Vapour, Soil, Stem and Leaf (Yakir)

-20

-15

-10

-5

0

5

10

15

20

6:00 9:00 12:00 15:00 18:00

time of day

del 1

8-O

Leafwater

StemWater

Soilwater

Vapour

data source: Yakir and Sternberg, 2000, Oecologia, 123, 297-311

Average precipAverage precip

Depletion during daytimeDepletion during daytime

Keeling Plot: Tucson, Arizona del D; (9am -3pm), Sept 1997

y = -580.13x - 81.033

R2 = 0.8926

y = -412.01x - 98.501

R2 = 0.8661

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140 0.160

1/[H2O]

del

D

Understory

Whole ecosystem

LELLEL

GMWL

GMWL

ConclusionsConclusions

• Semi-arid Israel and North America Israel: vapour<stem<leaf enrichment at optimum

Arizona: vapour became depleted during the dayKeeling plot analysis, using both 2H and 18O

indicates transpiration predominant flux of return vapour to atmosphere