Your SlideShare is downloading. ×
0
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Stable isotope analyses of vegetation across Australia_Eamus
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Stable isotope analyses of vegetation across Australia_Eamus

368

Published on

Published in: Technology, Travel
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
368
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
16
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide
  • fluxes of water vapour and CO2 above a land surfaceVapour Pressure Deficit, or VPD, is the difference (deficit) between the amount of moisture in the air and how much moisture the air can hold when it is saturated
  • Transcript

    • 1. Stable isotope (13C) analyses of vegetation across Australia Derek Eamus Rizwana Rumman Tomek Wyczesany with the co-operation of many Supersite Managers across Australia
    • 2. The Australian Supersite Network
    • 3. Site descriptions Veg Rainfall (mm) Temp (oC) Litchfield NT Savanna 1700 23 - 32 Far N Qld Simple notophyll vine forest 2000 + 23 - 29 Alice Springs NT Mulga (Acacia anuera) 300 14 - 30 SE Qld (peri-urban) a mix of dry eucalypt forest and wet heath 1000 15 - 26 WA mosaic of temperate woodland, heathland and mallee vegetation 245 11 - 25 Tumburumba wet eucalypt forest 900 5 - 20 Victoria dry eucalypt forest 675 7 - 18 Tasmania tall closed eucalypt forest 600 12 - 27 SA Undulating mallee woodland ; Calperum Mallee 225 10 - 25
    • 4. Aims of the study • Examine seasonal and spatial variability in WUE across Australia • Examine niche separation of co-occurring species • Determine the relative contributions of differences in A and gs to differences in WUEi across species and sites (needs Δ18O data of cellulose) • Determination of plant functional types based upon stable isotope analyses
    • 5. Extracting water (for deuterium and 18O analyses) from soil and stem segments using cryo-distillation
    • 6. Picarro analysers for water and C stable isotope analyses
    • 7. • Why do plants contain less 13C in their leaves than the CO2 in the air? 1. 13CO2 diffuses into leaves more slowly than 12CO2 2. Rubisco preferentially binds 12CO2  δ13Cplant = δ13Catm - (diffusion effect + enzyme effect) Discrimination
    • 8. • The δ13C of C3 plants reflects how much stomatal conductance limits photosynthesis. δ13Cplant, ‰ C3 plants C4 plants Source: Cerling et al., 1997 less stomatal limitation more stomatal limitation ci ≈ ca; ci/ca=1 Less δ13C More Δ Smaller WUEi ci << ca; ci/ca<1 More δ13C Less Δ Larger WUEi Source: Werner et al, 2012, Cerling et al., 1997
    • 9. • Farquhar, Ehleringer and Hubick (1989), proposed the equation for carbon isotope discrimination:  a = Diffusion effect (the rate of diffusion of 13CO2 across stomatal pore from atmosphere to leaf is lower by a factor of ~4.4‰ than 12CO2) a i c c aba )(  b = Isotope effect caused by preference of Rubisco for 12CO2 over 13CO2 ~27 ‰
    • 10. Ca CO2 Ci H2O wi wa gc gw • Carbon isotope discrimination is a measure of intrinsic water- use-efficiency (WUEi)  WUEi is the ratio of carbon assimilation to stomatal conductance (A/gw)  Photosynthesis, A = gc (ca-ci)  WUEi = A/gw = gc (ca-ci)/gw Source: Werner et al, 2012
    • 11. NSW data (2 spp per site) + Alice Springs Supersite + Robson Creek + GDE River Red Gum y = -0.0025x - 25.752 R² = 0.67 -34 -32 -30 -28 -26 -24 -22 -20 0 500 1000 1500 2000 2500 δ13C Annual rainfall (mm) Robson Creek (FNQ) River Red Gum, Alice Springs - using GW – thinks it is receiving 1800 mm of rainfall Alice Springs New South Wales data
    • 12. Comparing our data with Miller et al. 2001 (NT gradient) and Schulze et al. (1998; Qld gradient): y = 0.002x + 18.21 R² = 0.670 y = 0.002x + 18.17 R² = 0.701 y = 1.079ln(x) + 12.61 R² = 0.630 12 14 16 18 20 22 24 26 28 30 0 500 1000 1500 2000 2500 Delta(%o) Annual rainfall (mm)
    • 13. Comparing our data with Stewart et al. 1995 (S Qld) y = -0.0028x - 25.45 R² = 0.53 -32 -30 -28 -26 -24 -22 -20 0 200 400 600 800 1000 1200 1400 1600 1800 δ13C(%o) Annual rainfall (mm)
    • 14. What can we do with δ13C data? • Can use δ13C to calculate Δ (discrimination) since: Δ = (-8- δ13C )/(1+ δ13C /1000) • Can calculate WUEi and Ci/Ca from this: WUEi = (Ca*(27- Δ ))/(1.6*(27-4.4)) Ci/Ca = (Δ -4.4)/(27-4.4)
    • 15.  Using eddy covariance data available in the Supersites to compare ecoWUE and stable isotope assessments of WUEi Recent studies show that:  Ecosystem instantaneous water-use-efficiency ecoWUEinst and ecosystem intrinsic water-use-efficiency ecoWUEi are responsive to changes in soil moisture content and leaf-to- air VPD (Vickers et al. 2012)  an assessment at canopy-scales will enable the comparison across contrasting communities (Campos et al. 2013)
    • 16. WUEi across multiple sites y = -0.0258x + 87.48 R² = 0.67 0 10 20 30 40 50 60 70 80 90 100 0 500 1000 1500 2000 2500 Intrinsicwater-use-efficiency Mean annual rainfall (mm)
    • 17. Example of application of stable isotope analyses: Ecohydrological niche separation Can we identify contrasting strategies for water- use among co-existing plant species? – Moreno-Gutierrez et al 2012: δ13C used to disaggregate 10 co-occurring species along an ecophysiological gradient – Combined δ13C and Δ18O revealed a wide spectrum of degree of stomatal regulation of A – This correlated with WUEi and coexisting species maintained their species specific isotopic niches that reflect ecohydrological niche segregation
    • 18. Niche separation ? Variation in δ13C within a site across species is as large as across sites across a rainfall gradient – data from FNQ -35.00 -30.00 -25.00 -20.00 -15.00 -10.00 Alphitoniawhitei Elaeocarpusgrandis Flindersiabrayleyana Acaciacelsa Argyrodendronperlatum Melicopeelleryana Flindersiabrayleyana Homolanthusnovoguineensis Eiaeocarpusgrandis Elaeocarpusgrandis Alphitoniapetriei Flindersiabrayleyana Blepherocoryiainvoluaisula Flindersiabrayleyana Neolitseadealbata Elaeocarpusgrandis Castanospermumaustrale Cardwelliasublimis Plascospermuncoriaceum castanosporaalphandii Unknown Flindersiabrayleyana Elaeocarpusgrandis Unknown Aiphitoniapetriei Aleuritesrockinghamensis Alphitoniapetriei Flindersiabrayleyana Castanospermumaustrale Flindersiabrayleyana Flindersiabrayleyana Aleuritesrockinghamensis Acaciacelsa Unknown Alphitoniapetriei Aistoniascholaris Alstoniascholaris Unknown.(Kaoripine?) Alstoniascholaris δ13C%o
    • 19. Example of application of stable isotope analyses: Plant Functional Type Analyses Can we identify contrasting plant functional types using Δ13C ? – Werner and Maguas 2010: Compared Δ13C of across 11 species of contrasting PFT – Found pronounced and consistent variation in Δ13C across PFTs – correlated with phenology, leaf attributes (SLA, foliar N) – Principal component analyses showed Δ13C to be as good a predictor of PFT as using multiple leaf traits.
    • 20. Current data gaps • Samples from different PFTs • Wide selection of species across a site • Δ18O of leaf cellulose to disaggregate effects of gs from A
    • 21. The END Thanks for listening and any questions?
    • 22. Conclusions • Do species matter?
    • 23. Brief site descriptions • Litchfield Savanna: tall open eucalypt savanna in a tropical wet-dry climate; mean annual min/max temp of 23–32 oC; annual rainfall of 1700 mm • FNQ Rainforest: a simple notophyll vine forest in a tropical wet climate; mean annual min/max temp of 23–29 oC ; annual rainfall of 2000+ mm • Alice Mulga: open Mulga woodland savanna in a semi-arid climate; mean annual min/max temp of 14–30 oC; annual rainfall of 275 mm • SEQ Peri-urban: a mix of dry eucalypt forest and wet heath in a subtropical climate; mean annual min/max temp of 15–26 oC; annual rainfall of 1000 mm • Great Western Woodland: a mosaic of temperate woodland, heathland and mallee vegetation in a semi-arid climate; mean annual min/max temp of 11–25 oC; annual rainfall of 245 mm
    • 24. • Tumbarumba Wet Eucalypt: wet eucalypt forest in a temperate climate; mean annual min/max temp of 5–20 oC; annual rainfall of 900 mm • Victorian Dry Eucalypt: dry eucalypt forest is a temperate climate; mean annual min/max temp of 7–18 oC; annual rainfall of 675 mm • Warra Tall Eucalypt: a tall closed eucalypt forest in a temperate climate; mean annual min/max temp of 12–27 oC; annual rainfall of 600 mm • Cumberland Plain EucFace: remnant eucalypt woodland in a temperate climate; mean annual min/max temp of 11–24 oC; annual rainfall 700 mm • Calperum Mallee: an undulating mallee woodland in a semi-arid climate; mean annual min/max temp of 10–25 oC; annual rainfall of 225 mm

    ×