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Investigation:

CD-02 (Ehleringer / Martinelli)

LBA Dataset ID:

LBA_CDO2_O_H_ISOTOPES

Originator(s):

1. EHLERINGER, J.R.
2. MARTINELLI, L.A.
3. COOK, C.
4. DOMINGUES, T.F.
      5. FLANAGAN, L.
6. BERRY, J.A.
7. OMETTO, J.P.H.B.

Point(s) of Contact:

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (ornldaac@ornl.gov)

Dataset Abstract:

This data set reports the oxygen isotope signatures of water extracted from plant tissue (xylem from the stems and leaf tissue) and of atmospheric water vapor from twelve different sites (including both pasture and forest) throughout the Amazon region of Brazil. Samples were collected approximately every 4 months between 1999 and 2003 with additional samples collected monthly between January and May of 2003. In 2004 the collection of water samples from plant tissue continued at two sites, though water vapor collections were discontinued, and measurements of deuterium signatures were added to the analyses. In addition, water vapor from the troposphere was collected during a series of aircraft flights over the Tapajos National Forest in May of 2003 and analyzed for oxygen isotopes using the same methodology. There is one comma-delimited ASCII data file with this data set.

Beginning Date:

1999-03-01

Ending Date:

2004-09-30

Metadata Last Updated on:

2011-05-12

Data Status:

Archived

Access Constraints:

PUBLIC

Data Center URL:

http://daac.ornl.gov/

Distribution Contact(s):

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (ornldaac@ornl.gov)

Access Instructions:

PUBLIC

Data Access:

IMPORTANT: The LBA-ECO Project website is no longer being supported. Links to external websites may be inactive. Final data products from the LBA project can be found at the ORNL DAAC. Please follow the fair use guidelines found in the dataset documentation when using or citing LBA data.
Datafile(s):

LBA-ECO CD-02 Oxygen Isotopes of Plant Tissue Water and Atmospheric Water Vapor :  http://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=1008

Documentation/Other Supporting Documents:

LBA-ECO CD-02 Oxygen Isotopes of Plant Tissue Water and Atmospheric Water Vapor :  http://daac.ornl.gov/LBA/guides/CD02_O_H_Isotopes.html

Citation Information - Other Details:

Ehleringer, J., L.A. Martinelli, C. Cook, T.F. Domingues, L. Flanagan, J. Berry, and J.P. Ometto. 2011. LBA-ECO CD-02 Oxygen Isotopes of Plant Tissue Water and Atmospheric Water Vapor. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/1008

Keywords - Theme:

Parameter Topic Term Source Sensor
OXYGEN ISOTOPES BIOSPHERE VEGETATION LABORATORY MASS SPECTROMETER
OXYGEN ISOTOPES ATMOSPHERE ATMOSPHERIC WATER VAPOR LABORATORY MASS SPECTROMETER
OXYGEN ISOTOPES BIOSPHERE VEGETATION LABORATORY MASS SPECTROMETER
OXYGEN ISOTOPES ATMOSPHERE ATMOSPHERIC WATER VAPOR LABORATORY MASS SPECTROMETER

Uncontrolled Theme Keyword(s):  ATMOSPHERIC WATER VAPOR, DEUTERIUM, OXYGEN ISOTOPE, PLANT WATER, STABLE ISOTOPE

Keywords - Place (with associated coordinates):

Region
(click to view profile)
Site
(click to view profile)
North South East West
  RONDONIA AMAZONAS (MANAUS) PARA WESTERN (SANTAREM) 1.00000 -10.76180 54.57920 -62.35720

Related Publication(s):

Ehleringer, J.R., D.R. Bowling, L.B. Flanagan, J. Fessenden, B. Helliker, L.A. Martinelli, and J.P. Ometto. 2002. Stable isotopes and carbon cycle processes in forests and grasslands. Plant Biology 4(2):181-189.

Lai, C.T., J.P.H.B. Ometto, J.A. Berry, L.A. Martinelli, T.F. Domingues, and J.R. Ehleringer. 2008. Life form-specific variations in leaf water oxygen-18 enrichment in Amazonian vegetation. Oecologia 157(2):197-210. DOI 10.1007/s00442-008-1071-5.

Ometto, J.P.H., L.B. Flanagan, L.A. Martinelli, and J.R. Ehleringer. 2005. Oxygen isotope ratios of waters and respired CO2 in Amazonian forest and pasture ecosystems. Ecological Applications 15(1):58-70.

Data Characteristics (Entity and Attribute Overview):

Data Characteristics:

Data are presented in one comma-delimited ASCII file: CD02_Stable_Isotope_Water.csv



Column Heading Units/format Description

1 Region Sampling region

2 Site Sampling site within the region

3 Longitude decimal degrees Longitude of sampling site in 4 Latitude decimal degrees Latitude of sampling site5 Year 5 Year YYYY Year of collection

6 Month MM Month of collection

7 Time HHMM Time at which sample was collected in local time 24 hour clock

8 Ecosystem Ecosystem type: forest, lake, pasture, or flight for atmospheric collections

9 Sample_type Form in which sample was collected (leaf/stem/soil/rain/water vapour)

10 Description Description of sample and/or sampling conditions where noted

11 Local_name Common name of tree, shrub, or grass where identified

12 Scientific_name Scientific name of tree, shrub, or grass with family in parenthesis where noted

13 delta_18O parts per mil Isotopic ratio of 18O/16O referenced to SMOW

14 delta_D parts per mil Isotopic ratio of deuterium to hydrogen referenced to SMOW

15 Sampling_height meters Height in meters (m) at which sample was collected



Missing values are indicated as 9999.Year, month, and collection time only are reported; no day of collection provided.

Missing character values: not provided

Example data records:

Region,Site,Longitude,Latitude,Year,Month,Time,Ecosystem,Sample_type,Description,

Local_name,Scientific_name,delta_18O,delta_D,Sampling_height

Manaus,ZF2 km 14,-2.58900,-60.11520,1999,3,1645,Forest,leaf,random sampling,

not provided,not provided,11.28,9999,25

Manaus,ZF2 km 14,-2.58900,-60.11520,1999,3,1715,Forest,leaf,random sampling,

not provided,not provided,17.02,9999,0.5

...

Rondonia,Fz N Senhora,-10.7618,-62.3572,2000,9,1215,Pasture,leaf,grass W54,

not provided,not provided,10.3,9999,0.4

Rondonia,Fz N Senhora,-10.7618,-62.3572,2000,9,1220,Pasture,leaf,grass W55,

not provided,not provided,12.5,9999,0.3

...

Santarem,km 83,-3.01639,-54.95083,2002,3,1430,Forest,water vapor,5 min.,

not provided,not provided,-13.16,9999,31

Santarem,km 83,-3.01639,-54.95083,2002,3,1430,Forest,water vapor,6 min.,

not provided,not provided,-11.72,9999,21

...

Santarem,SECA Dry,-2.8570,-54.9590,2002,10,1519,Forest,leaf,ST1-6-35_Matamata,

Matamata,Eschweilera sp.,4.93,9999,11

Santarem,SECA Dry,-2.8570,-54.9590,2002,10,1519,Forest,stem,ST1-6-35_Matamata,

Matamata,Eschweilera sp.,-0.26,9999,11

Data Application and Derivation:

The oxygen isotope ratio (delta 18O) of atmospheric CO2 is a powerful indicator of large-scale CO2 exchange on land. Oxygen isotope exchange between CO2 and water in leaves and soils controls the delta 18O of atmospheric CO2. The data presented here can be used to validate current models including the Craig-Gordon model. These data can also be used to calculate discrimination against isotopically \'heavy\' CO2 during photosynthesis for both pasture and forest ecosystems.

Quality Assessment (Data Quality Attribute Accuracy Report):

Quality Assessment:

Standard samples were run along with the field samples for all analyzes to check the calibration of the instruments. There are no known problems with the data.

Process Description:

Data Acquisition Materials and Methods:

Site Descriptions



The sites were located within the Amazon Basin near Santarem, Manaus, and Ji-Parana, Brazil. In each region, measurements were collected at forest and pasture sites. Each of the forest sites were primary evergreen forests (��terra firme��) with a mean canopy height of 30�35 m, although some emergent trees reached 45� 50 m. The primary forest site near Santarem was located 67 km south of the city, in an area between the Tapajos River and the highway BR 163. The forest covers an area of 600,000 ha and was established as a national forest in 1974 (FLONA Tapajos). The Santarem pasture site was located 77 km south of Santarem. The Manaus forest site was located 70 km from the city, in a forest reserve controlled by the Instituto Nacional de Pesquisas Amazonicas (INPA). The Manaus pasture site was located about 60 km from the forest site, along a secondary road (ZF-3). The grass at this site had less vigorous growth than the Santarem pasture grass. The Ji-Parana primary forest site (Rebio Jaru,) was a reserve controlled by the Brazilian Environment Protection Agency (IBAMA), located north of Ji-Parana (80 km), by the Machado River (120 m above sea level). The pasture site (Fazenda Nossa Senhora da Aparecida) was a cattle ranch 50 km northeast from Ji-Parana (Ometto et al., 2005).



Plant tissue water and water vapor from the canopy:



Water samples were collected to characterize the stable isotope ratios of different water compartments in pasture and forest ecosystems. Xylem water samples were collected from stems to determine plant water sources in the soil. Leaves were sampled for their leaf water, and atmospheric water vapor was trapped so that leaf water values could be modeled. The leaves and stems were collected from several heights within the forest canopy, placed immediately inside individual glass vials sealed with a rubber stopper and wrapped with Parafilm. The samples were kept cold (0-5 degrees C) in the field and later frozen in the lab. Tropospheric water vapor was collected by flights of a small airplane from the surface to above PBL. Air was pumped at different moments through dry ice water traps.



Isotopic analyses:



Water was extracted from the samples using cryogenic vacuum distillation (Ehleringer et al. 2001). Oxygen isotope ratios for all water samples were determined by equilibration of water with CO2 (Socki et al. 1999). Measurements of the oxygen isotope composition of the equilibrated CO2 were performed by online injection of CO2 into a coupled gas chromatograph and isotope ratio mass spectrometer (Delta Plus, Finnigan MAT, Bremen), operating in a continuous flow mode (Fessenden et al. 2002).

References:

Ehleringer, J.R., J. Roden, and T.E. Dawson. 2001. Assessing ecosystem-level water relations through stable isotope ratio analyses, in Methods in Ecosystem Science, O.E. Sala, R.B. Jackson, H.A Mooney, and R.W. Howarth, pp 181-198, Springer Verlag, New York.



Fessenden, J.E., C.S. Cook, M.J. Lott, and J.R. Ehleringer. 2002. Rapid 18O analysis of small sized water samples using a continuous-flow isotope ratio mass spectrometer. Rapid Communications in Mass Spectrometery 16:1257-1260. doi:10.1002/rcm.711







Helliker , B.R., J.S. Roden, C.S. Cook, and J.R. Ehleringer. 2002. A rapid and precise method for sampling and determining the oxygen isotope ratio of atmospheric water vapor. Rapid Communications in Mass Spectrometry 16:929-932.doi:10.1002/rcm.659





Hodnett, M. G., M. D. Oyama, J. Tomazella, and A. de O. Marques Filho. 1996. Comparisons of long term soil water storage behavior under pasture and forest in three areas of Amazonia. Pages 79â�â�œ100 in J. H. C. Gash, C. A. Nobre, J. M. Roberts, and R. L. Victoria, editors. Amazonian deforestation and climate. John Wiley and Sons, Chichester, UK.



Ometto, J.P.H., L.B. Flanagan, L.A. Martinelli, and J.R. Ehleringer. 2005. Oxygen isotope ratios of waters and respired CO2 in Amazonian forest and pasture ecosystems. Ecological Applications 15(1):58-70.doi:10.1890/03-5047







Socki, R. A., C. S. Romanek, and E. K. Gibson. 1999. On-line technique for measuring stable oxygen and hydrogen isotopes from microliter quantities of water. Analytical Chemistry 71:2250-2253. doi:10.1021/ac981140i

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