Environment and some features of 300- year-old larch V. - - PowerPoint PPT Presentation

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Environment and some features of 300- year-old larch V. - - PowerPoint PPT Presentation

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Environment and some features of 300- year-old larch V. Sapozhnikova, 1 B. Ageev,1 Yu. Ponomarev,1 D. Savchuk 2 1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Sciences 634021, Russia, Tomsk,

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SLIDE 1

Environment and some features of 300- year-old larch

  • V. Sapozhnikova, 1 B. Ageev,1 Yu. Ponomarev,1
  • D. Savchuk 2

1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Sciences 634021, Russia, Tomsk, Academician Zuev Square, 1 sapo@asd.iao.ru ,ageev@asd.iao.ru, yupon@iao.ru, 2 Institute of Monitoring of Climatic and Ecological Systems of Siberian Branch of the Russian Academy

  • f Sciences, 634055 Russia, Tomsk,

Academichesky prospekt, 10/3 savchuk@imces.ru

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SLIDE 2
  • R. O. Teskey, A. Saveyn, K. Steppe and M. A. McGuire (2008)

“Origin, fate and significance of CO2 in tree stems”,

New Phytologist , 177: 17–32

  • Fig. 1 Schematic of important sources and sinks of CO2 inside a

stem segment of a tree: (a) - inner bark 1) diffusion of CO2 out of the stem, 2) fixation of CO2 3) CO2 diffusing into the transpiration stream (b) - cambium (c)- xylem ray cells (d)- xylem sap corticular photosynthesis gas-analyzer

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SLIDE 3

The aim of this work is:

to show that an analysis of variations in CO2 and H2O extracted under vacuum from tree rings in discs enables present views about CO2 and H2O functions in tree life to be extended and their association with climate changes and plant growth trends under changing environmental conditions to be understood.

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SLIDE 4

Block-diagram of a photoacoustic laser spectrometer

  • Waveguide CO2 laser (1) [1],
  • photoacoustic cell (2),
  • microphone cell with

homemade plane capacitor microphone (3),

  • photodetector (4),
  • electric signal measuring and

recording system (5),

  • computer (6),
  • pump (7),
  • CO2/N2 reference mixture (8).

The system was pre-calibrated with a known amount of CO2 ,

  • exposure chambers (9).

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Fig.1.Block-diagram of a laser spectrometer

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SLIDE 5

940 950 960 970 980 0,0 0,5 1,0 1,5 2,0 2,5

  • 4
  • 2

2 Absorption coefficient H2O, Km-1 Absorption coefficient CO2,Km-1 cm-1 H2O CO2+H2O R(20) P(20) P(16) P(14) CO2 H2O

Fig.2.CO2 waveguide laser lines and H2O water vapour spectrum

Our experimental system and procedure for investigations into CO2 and H2O in disc tree rings are described elsewhere . The CO2 and H2O content in samples vacuum-extracted from tree rings was measured by a laser photoacoustic gas analyzer with a sealed-off waveguide CO2 laser using high-frequency excitation. The measurements were performed in four tunable CO2 laser lines: 10 P (20, 16, 14) coinciding with CO2 absorption lines and 10 R (20) coinciding with CO2 and water vapor absorption lines (CO2+H2O). 1700 gas samples of Siberian stone pine discs, Scots pine discs, Siberian spruce discs from Tomsk and Altay Mountains were investigated. All tree discs were stored under laboratory conditions before measurements. Thus the wood material can be considered room-dried. An isotope analysis of carbon of desorbed CO2 in a few annual rings was made (63 samples). The carbon isotope composition of atmospheric CO2 is known to be, on average, δ13C, (‰) = – 8.07 ‰, with leaves and tree wood being characterized by a lower carbon isotope composition (from – 20 ‰ to – 30 ‰ .)

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SLIDE 6

Experiment 1

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Fig.3. CO2 and (CO2+H2O) variations in disc tree rings of the Siberian stone pine (rel. units). Fig.4. CO2 content in tree rings and annual ring width

CO2 rise!

Cyclicity, CO2, ppm

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SLIDE 7

Is there a climatic response of CO2 and H2O tree ring distributions?

Fig.5. Spectral density of the CO2 and (CO2+H2O) content for a 95 % confidence interval.

A wavelet analysis, high-resolution spectral and cross-spectral analyses and digital time series filtration procedure were used for an annual CO2 and H2O distribution analysis relating to Siberian stone pine disc tree rings. Our first step was to look at the existence of climatic signal in our results.

Fig.6. Four-year components of wavelet transform for CO2 content (1), signal (H2O+CO2) ( 2, left vertical axis), and precipitation amount during dormant period ( 3, right vertical axis)

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Correlation coefficients R

4-year period

R, CO2 – precipitation (dormancy period)

  • 0,4

variations > 5 years

R, CO2 – temperatures (vegetation period)

  • 0,43

R, width – precipitation (vegetation period)

R=0.26 (variations ≤ 5 years), R=0.27 (4 year variations)

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SLIDE 9

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  • Fig. 7. Annual

variations of the tree ring CO2 content and width in Scots pine disc No. 6. (Pinus sylvestris L.)

4-year cycles CO2, ppm 1960

1920 1940 1960 1980 2000 500 1000 1500 2000 2500 3000 3500 4000 0,0 0,5 1,0 1,5 2,0 2,5 3,0

1

Width, mm(2) Disc CO2, ppm (1)

2 2 1

Year 1900 1920 1940 1960 1980 2000 2020 2000 4000 6000 8000 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0

Width , mm (2) Disc CO2 , ppm (1) Year

1 2 2 1

Fig.8. Annual variations of the tree ring CO2 content and width in Scots pine disc

  • No. 12.

1960 1960

Experiment 2

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SLIDE 10

Experiment and Result 3

Fig.10. Annual variations in the CO2 content in tree rings

  • f the larch disc (village Chernorud,

Lake Baikal). (Priol’khonie, where

Chernorud is situated, is the driest area near Lake Baikal.)

  • Fig. 9. Annual variations in the CO2

content in tree rings

  • f the Siberian stone pine disc from

Seminsky Range (1650 m above sea

level, Altai Republic, Altai Mountains).

There is a distinct tendency to a decrease in the CO2 content in tree rings with age. 10

1940 1960 1980 2000 200 400 600 800 1000

CO2, ppm Year 1987

1961 1944

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SLIDE 11

Experiment and Result 4

Fig.11. Annual variations in the carbon isotope composition of CO2.

Fig.13. Annual CO2 and carbon

isotope composition in a larch disc. Fig.12. Comparison of the variations in the carbon isotope composition of desorbed CO2 with δ13 С of cellulose [Hilasvuori,E. Dissertation,

https://helda.helsinki.fi/bitstream/handle/10138/25679/environm.pdf?sequence=1 ].

Fig 14. Comparison of the carbon isotope composition

  • f desorbed CO2 with δ13 С in the atmosphere

[Francey R.J., Allison C.E., Etheridge D.M., Trudinger C.M., Enting I.J.,

Leuenberger M., Langenfelds R.L., Michel E., and Steele L.P. 1999. „1000-year high precision record of δ13C in atmospheric CO2” T ellus (1999), 51B, 170–193 ].

1750 1800 1850 1900 1950 2000

  • 26,5
  • 26,0
  • 25,5
  • 25,0
  • 24,5
  • 24,0
  • 23,5
  • 23,0

Delta 13C CO2 Cellulose Delta 13C cellulose year

  • 34
  • 32
  • 30
  • 28
  • 26
  • 24
  • 22

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SLIDE 12

Fig.15. Annual variations in photoacoustic signals in laser lines (results smoothed out by a 11- year running average).

1700 1750 1800 1850 1900 1950 2000 2050 0,04 0,06 0,08 0,10 0,12 0,14 0,16 0,18 Photoacoustic H2O, CO2 signals, rel.units Year CO2 H2O

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SLIDE 13

Fig.9. Amplitude spectrum of larch tree ring CO2.

Fig.8. Superposition of long-term cyclicity on short-term cycles of the annual CO2 distribution in the disc tree rings of a 300-year larch. 13 CO2 rise!

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SLIDE 14

Effect of climatic factors on Larch CO2

TEMPERATURE PRECIPITATION Precipitation

  • f dormancy

period

(November-March)

temperature

  • f April

temperature

  • f August

by 0,56 by -0,37 by 0,39 The step-by-step increase of the moving lag (by 11-year) rises the coefficient of correlation at the same sign. 14

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Conclusions

  • The results obtained from investigations into the vacuum-extracted

CO2 and H2O content in larch tree disc rings have shown that a considerable portion of these substances is stored in annual ring wood, i.e., in tree stems. As stem CO2 originates from respiring cells in tree stems and roots , CO2 rise is likely to be due to an increase in cell respiration. Our measurements show that this is a cyclic process, with the main cycle being a 4-year period modulated by long-term cycles.

  • A comparison of the annual CO2 variations obtained for two larch

discs shows that an unfavorable habitat (e.g., very dry climate) can change the sign of the annual CO2 trends in tree rings. Thus, it may be concluded that environmental changes can influence stem respired CO2 through changes in the cyclicity. Moreover, it can be assumed that atmospheric CO2 rise and elevated surface temperatures observed since 1960 have changed the annual diffusion pattern of stem CO2 and caused it to accumulate.

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Acknowledgments

  • This work was supported by the Siberian Branch of the

Russian Academy of Sciences (Project VII.66.1.3).

  • We would like to thank the staff of Laboratory of Isotope

Organic Geochemistry (Tomsk, Russia) for performing an isotope analysis .

  • We would also like to express sincere thanks to N. P.

Baidin, director of Tomsk Forest Museum, for a 300-year

  • ld larch disc, and
  • Dr. T. Chesnokova for CO2,H2O spectra calculations.

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