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  Folha Amazônica


CD-02 (Ehleringer / Martinelli)

LBA Dataset ID:



      4. KRUIJT, B.

Point(s) of Contact:

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (

Dataset Abstract:

Samples of leaves at various heights within the canopy and atmospheric air were collected along a topographical gradient in the ZF2 Reserve near Manaus during the dry season to test whether the delta 13C leaf of sunlit leaves and the carbon isotope ratio of ecosystem respired CO2 may be more negative in the valley than those on the plateau. In addition to delta 13C of leaf tissue and atmospheric CO2 leaf carbon and nitrogen concentrations are reported as well as delta 15N for leaf tissue. Data were collected in 2004 from various heights within the canopy and again in 2006 from only canopy leaves from identified species.

Beginning Date:


Ending Date:


Metadata Last Updated on:


Data Status:


Access Constraints:


Data Center URL:

Distribution Contact(s):

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (

Access Instructions:


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.

LBA-ECO CD-02 C and N Isotopes in Leaves and Atmospheric CO2, Amazonas, Brazil :

Documentation/Other Supporting Documents:

LBA-ECO CD-02 C and N Isotopes in Leaves and Atmospheric CO2, Amazonas, Brazil :

Citation Information - Other Details:

de Araujo, A.C., J.P.H.B. Ometto, A.J. Dolman, B. Kruijt, M.J. Waterloo and J.R. Ehleringer. 2012. LBA-ECO CD-02 C and N Isotopes in Leaves and Atmospheric CO2, Amazonas, Brazil. Data set. Available on-line [ ] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A

Keywords - Theme:

Parameter Topic Term Source Sensor


Keywords - Place (with associated coordinates):

(click to view profile)
(click to view profile)
North South East West
Amazonas (Manaus) ZF2 km 34 -2.50000 -2.60900 -60.00000 -60.20910

Related Publication(s):

de Araujo, A.C., J. P. H. B. Ometto, A. J. Dolman, B. Kruijt, M. J. Waterloo and J. R. Ehleringer.2008. Implications of CO2 pooling on delta13C of ecosystem respiration and leaves in Amazonian fores. Biogeosciences, 5: 779-795.

Data Characteristics (Entity and Attribute Overview):

Data Characteristics:

Data are presented in three comma-delimited ASCII files.

File #1: CD02_Gas_Samples_13C_2004_2006.csv

File #2: CD02_Foliar_13C_15N_2004_2006.csv

File #3: CD02_Met_and_flux_data_2004_2006.csv

File #1:


File contents and organization:

Column,Heading,Units/format,Variable description

1,Year,,Year in which samples were collected

2,Month,,Month in which samples were collected. January is represented by 1 and December by 12

3,Day,,Day of the month in which samples were collected

4,Time,HH:MM,Start of sample collection in local time. Local time is GMT -4

5,Flask,,Flask identification number for laboratory purposes

6,Position,,Location within the landscape: plateau slope or valley

7,Sample_type,,Samples are either atmospheric gas samples collected in flasks or soil respiration samples collected from a 40L chamber placed on the soil surface

8,Height,m,Height in meters above the ground at which the sample was collected for the atmospheric samples

9,conc_CO2,ppm,Measured concentration of carbon dioxide in the sample in parts per million (ppm)

10,inv_conc_CO2,ppm-1,Inverse concentration of carbon dioxide in the sample calcluted as 1/ column 8

11,delta_13C_R1,parts per mil,Isotopic ratio of 13C/12C in carbon dioxide referenced to PDB, measured with continuous flow on Finigan Delta Plus at CENA

12,delta_13C_R2,parts per mil,13C/12C ratio measured in second replicate from the same sample where available

13,delta_13C_R3,parts per mil,13C/12C ratio measured in third replicate from the same sample where available

14,delta_13C_Avg,parts per mil,Mean isotopic ratio of 13C/12C in carbon dioxide based on all replicates run

Example data records:
















File #2:


File contents and organization:

Column,Heading,Units/format,Variable description

1,Year,,Year in which sample was collected

2,Month,,Month in which sample was collected: January is represented by 1 and December by 12

3,Day,,Day of the month on which sample was collected

4,Location,,Topographic location of sampling point: plateau slope or valley. In 2006 campinarana was added to the list as a forest type that only occurs at lower slope and valley locations

5,Height,m,Height of sampling location in meters above ground level

6,Sample_id,,Internal sample ide

7,Sample_type,,Type of material sampled: leaves with mature and young leaves distinguished in 2006 or litter

8,Canopy_position,,Location within the canopy based on sample height

9,Species,,Species identification where noted: In 2004 species were identified only with local name where possible in 2006 species were identified with scientific names

10,Description,,Notations from original field notebooks

11,delta_15N,per mil,Isotopic ratio of 15N/14N in the leaf sample referenced to PDB, measured with continuous flow on Finigan Delta Plus at CENA

12,delta_13C,per mil,Isotopic ratio of 13C/12C in the leaf or litter sample referenced to PDB, measured with continuous flow on Finigan Delta Plus at CENA

13,conc_C,percent,Concentration of carbon in the leaf or litter sample measured by dry combustion and reported in percent by weight

14,conc_N,percent,Concentration of nitrogen in the leaf or litter sample measured by dry combustion and reported in percent by weight

15,C_to_N,,Mass based ratio of carbon to nitrogen in the leaf or litter sample calculated by dividing column 13 by column 14

16,Notes,,Comments from the field notebooks

Example data records:


2004,8,2,Valley,25,2,leaves,Canopy,not identified,AM 02 BAIXIO - ZF2 KM 34 25m,0.06,-31.55,49.54,1.23,40.26,-9999

2004,8,2,Valley,25,3,leaves,Canopy,not identified,AM 03 BAIXIO - ZF2 KM 34 25m,-0.1,-31.58,52.32,2.45,21.36,-9999

2004,8,2,Valley,25,4,leaves,Canopy,not identified,AM 04 BAIXIO - ZF2 KM 34 25m,-1.87,-31.88,48.91,0.91,53.83,-9999

2004,8,2,Valley,20,5,leaves,Canopy,not identified,AM 05 BAIXIO - ZF2 KM 34 20m,1.61,-35.46,53.19,1.72,30.98,-9999

2004,8,2,Valley,7,6,leaves,Understory,not identified,AM 06BAIXIO - ZF2 KM 34 7.0m,1.91,-35.08,47.51,1.44,33.03,-9999

2004,8,5,Plateau,30,7,mature leaves,Canopy,Copaiba,AM 08 PLATO ZF2 COPAIBA F. MADURAS 30m,3.29,-29.09,54.3,2.41,22.57,-9999

2004,8,5,Plateau,30,8,new leaves,Canopy,Copaiba,AM 09 PLATO ZF2 COPAIBA F. NOVAS 30m,3.77,-27.26,51.11,3.8,13.45,-9999

2004,8,5,Plateau,26,9,leaves,Canopy,not identified,AM10 PLATO ZF2 26m,4.49,-29.8,51.44,1.96,26.21,-9999

2004,8,5,Plateau,24,10,leaves,Canopy,not identified,AM11 PLATO ZF2 24m,1.4,-26.78,47.13,1.01,46.63,-9999

File #3:


File contents and organization:

Column,Heading,Units/format,Variable description

1,Year,YYYY,Year in which data were collected

2,Day,,Day of the year on which data were collected

3,Time ,,Sampling point in decimal hours. Time given is the end of the sampling period

4,Temp_Air,degrees C,Air temperature in degrees Celsius

5,RH ,percent,Relative humidity in percent

6,E_act,kPa,Actual water vapor pressure reported in kilopascals

7,E_sat,kPa,Saturated water vapor pressure in kilopascals

8,VPD,kPa,Vapor pressure defict reported in kilopascals

9,Fco2,umol/m2/s,Carbon dioxide flux measured at 53 m height

10,CO2_conc,ppm,Atmospheric carbon dioxide concentration measured at 53 meters above ground level

11,u_star,m/s,Friction velocity measured at 53 meters above ground level


Missing data is represented by -9999.

All data were measured at the top of the KM34 tower at 53 meters above ground level. The tower is located on the plateau.

All data are averages from a 30 minute sampling period: For the meteorological data each sampling period included 60 measurements (scan time interval 30 seconds); for the flux data each sampling period includes 18000 samples (scan time interval 0.1 seconds).

Example data records:
















Data Application and Derivation:

Measurements of carbon stable isotope ratios of atmospheric CO2 are a powerful indicator of large-scale CO2 exchange on land across multiple spatial scales. Stable carbon isotope composition of leaf tissue and CO2 released by respiration (delta r)can be used as an estimate of changes in ecosystem isotopic discrimination that occur in response to seasonal and interannual changes in environmental conditions. Understanding of carbon dioxide stable isotope composition can play a central role in influencing our understanding of the extent to which terrestrial ecosystems are carbon sinks.

Quality Assessment (Data Quality Attribute Accuracy Report):

Quality Assessment:

All data have been thoroughly checked and are final. Data quality control measures for the laboratory analyses are described in the Methods section below.

Process Description:

Data Acquisition Materials and Methods:

Site Description:

Measurements were made at the Manaus LBA site located in the Asu catchment in the Reserva Biologica do Cuieiras. The forest belongs to the Instituto Nacional de Pesquisas da Amazonia (INPA). The mean air temperature was 26 degrees C between July 1999 and June 2000 (Araujo et al., 2002). Average annual rainfall

is about 2400 mm, with a distinct dry season during July, August and September when there is less than 100 mm rainfall per month (Araujo et al., 2002).

There is very little large-scale variation in topography in the region, but at a smaller scale, the dense drainage network has formed a pattern of plateaus and valleys. The mean elevation is about 100 ma.s.l. with about 40 to 60 m difference between plateaus and valleys bottoms. The soils along a typical

toposequence consist of well-drained Oxisols and Ultisols on plateaus and slopes, respectively, and poorly drained Spodosols in the valleys (Chauvel et al., 1987). The vegetation is old-growth closed-canopy terra firme (non-flooded) forest. Variation in soil type, topography and drainage status has created distinct patterns in forest vegetation composition. On the plateaus, well drained clay soils favor high biomass forests 35 to 40m in height with emergent trees over 45m tall: typical terra firme forest. Along the

slopes, where a layer of sandy soil is deepening towards the valley bottom, forest biomass is lower and height is around 20 to 35m with few emerging trees. In the valleys, the sandy soils are poorly drained and usually they remain waterlogged during the rainy season, supporting low biomass and low tree

height (20 to 35 m), with very few emerging trees. A distinct forest type, classified as Campinarana (as it resembles the Campina forest that develops on white sand areas), also occurs between the lower slope and valley bottom areas. This vegetation has lower biomass, tree diversity and tree height (15 to 25 m) (Guillaumet, 1987:Luizao et al., 2004). The forest canopy is stratified in four layers. The first layer is formed by emergent trees, reaching heights of 35 to 45m above ground level (a.g.l.). Below this layer, there are trees with their canopies between 20 and 35 m. The third layer is formed by understory regeneration, whereas shrubs and seedlings form a fourth layer close to the ground. More elaborate descriptions of the site can be found in Araujo et

al. (2002) and Luizao et al. (2004).

Air sampling collection and data conditioning

All sampling was carried out in representative plots along a transect that was divided into 3 topographical sections: plateau, slope and valley. In each plot, air samples were collected at different levels above and within the canopy for delta 13C atmospheric analysis. Each profile sampling system consisted of high-density polyethylene (HDPE) tubes (Dekoron 1300, 6.25mm OD, non-buffering ethylene copolymer coating, USA) with intakes at different heights. Nylon funnels with stainless steel filters were installed on the air intakes to avoid sample contamination by particles. A battery-operated air pump (Capex V2X, UK) was used to draw air through the tubing, a desiccant tube containing magnesium perchlorate and a glass sample flask. The flow rate was 10 L per minute. The longest air sampling tube had an internal volume of about 0.65 L that corresponds to a maximum residence time of 4 s. All air samples were collected in pre-evacuated 100mL glass flasks that were closed with two high-vacuum Teflon stopcocks (34-5671, Kontes Glass Co., USA) after air had been pumped through the flask for about 3 minutes. The atmospheric C concentration was measured at the same time with an infrared gas analyzer (IRGA) (LI- 800, LI-COR, Inc., USA). For this a T piece was connected at the air pump output, which allowed a low sub-sampling flow of about 800mL per min to be passed through the IRGA. Plateau air samples were collected at K34 tower (118m a.s.l.) with a tube system attached to it. The slope profile system was suspended from the highest branch of a tall tree located about midway down the slope (89.2ma.s.l.) at 550m from the K34 tower, whereas the valley profile system, which was suspended in the same way as that on the slope, was installed in the valley (77.3ma.s.l.) at about 850m from the K34 tower. In October 2006, the valley profile system was relocated 500 m to the west and attached to the newly erected B34 tower. Nighttime sampling began about one hour after sunset (about 19:30 local time) and ended about one hour before sunrise (about 05:30 local time) to avoid any effects of photosynthesis on the estimates of delta13C Reco. Daytime values of delta13Ca within and above the canopy were obtained between 07:00 and 18:00 h (local time).

Sampling of foliage and litter

In August 2004, leaf samples were collected once from trees at each topographical section by a tree climber, sampling a vertical profile through the forest canopy. The sampling heights were not uniform among the topographical sections, as follows: plateau (3, 10, 17, 21, 24, 26, and 30ma.g.l.), slope (3, 8, 10, 12, 20, 26, 28, 30 ma.g.l.), and valley (3, 7,

20, 2 5ma.g.l.). There was no botanical classification for the trees sampled in August 2004. In October 2006, sun leaves at the top of the canopy were collected once by a tree climber at plateau and valley sections. Trees with botanical classification to species level were now systematically selected according to either their importance value index (IVI) or occurrence

at both plateau and valley areas (Oliveira and Amaral, 2004; Oliveira and Amaral, 2005). Each sample from a single tree consisted of at least five healthy leaves that were combined according to their status (either mature or young). In August 2004, litter samples were randomly collected at each topographical section. These were bulked by topographic section to form

single samples. The samples were pre-dried at ambient air temperature for 3 days in a home-made greenhouse located an open-sky area and shipped to CENA for stable isotope ratio and elementary analyses.

Soil-respired CO2 sampling

In August 2004, CO2 released from the soil was sampled at each topographical section using the protocol described by Flanagan et al. (1999) and Ometto et al. (2002). The sampling was repeated at plateau and valley sites in October

2006 and now included the Campinarana site. Samples were collected using a stainless steel chamber with an internal volume of about 40 L and a small electric fan to enhance mixing within the chamber. Samples were collected at two

sites in each topographical section. At each site, five sample flasks were filled using five minutes time intervals between sampling for determining the carbon isotope ratio of soil respired CO2 (delta13CRsoil).

Laboratory analyses

The delta13Ca in sample flasks were measured using a continuous-flow isotope-ratio mass spectrometer (IRMS) (Delta Plus, Finnigan MAT, Germany) as described by Ehleringer and Cook (1998) and Ometto et al. (2002). Measurement precision of this method was 0.13 percent for 13C (Ometto et al., 2002). The air remaining in the flask after stable isotope ratio analysis was used to measure ca using a system similar to that described by Bowling et al. (2001a).

Measurement precision and accuracy of this method were 0.2 and 0.3 ppm, respectively (Ometto et al., 2002). Leaf and litter samples were dried at 65 degrees C to constant weight, then ground with mortar and pestle to a fine powder. A 1 to 2 mg subsample of ground organic material was sealed in a tin capsule and placed into an elemental analyzer (Carlo Erba Instruments, Model EA 1110 CHNS-O, Milan, Italy) for combustion and subsequent elemental C and N analysis. The CO2 generated by combustion was purified in a gas chromatograph column and passed directly to the inlet of the IRMS (Delta Plus, Finnigan MAT, USA) operating in continuous-flow mode. These provided stable isotope ratios of carbon, oxygen and nitrogen (13C/12C; 18O/16O; 15N/14N) with a measurement

precision of 0.2percent (Ometto et al., 2006). The carbon isotope ratio was expressed in the delta notation (delta), which relates the measured 13C/12C molar ratio of the sample and the international Pee Dee Belemnite (PDB) limestone standard(Ehleringer and Rundel, 1989).


Araujo, A. C., Nobre, A. D., Kruijt, B., Elbers, J. A., Dallarosa, R., Stefani, P., von Randow, C., Manzi, A. O., Culf, A. D., Gash, J. H. C., Valentini, R., and Kabat, P.2002. Comparative measurements of carbon dioxide fluxes from two nearby towers in a central Amazonian rainforest: The Manaus LBA site, J. Geophys. Res.- Atmos., 107(D20),8090, doi:10.1029/2001JD000676.

Bowling, D. R., Cook, C. S., and Ehleringer, J. R.2001. Technique to measure CO2 mixing ratio in small flasks with a bellows/IRGA system, Agricultural and Forest Meteorology: 109, 61-65.

Chauvel, A., Lucas, Y., and Boulet, R.1987. On the genesis of the soil mantle of the region of Manaus, Central Amazonia, Brazil, Experientia, 43: 234-241.

Ehleringer, J. R. and Rundel, P. W. 1989. Stable isotopes: History, units, and instrumentation, in: Stable isotopes in ecological research, 1st ed., edited by: Rundel, P. W.,

Ehleringer, J. R., and Nagy, K. A., Ecological studies, Springer-Verlag, New York, USA, 1-15.

Ehleringer, J. R. and Cook, C. S. 1998. Carbon and oxygen isotope ratios of ecosystem respiration along an Oregon conifer transect: preliminary observations based on small-flask sampling, Tree Physiology, 18, 513-519.

Flanagan, L. B., Kubien, D. S., and Ehleringer, J. R. 1999. Spatial and temporal variation in the carbon and oxygen stable isotope ratio of respired CO2 in a boreal forest ecosystem, Tellus Series B Chemical and Physical Meteorology, 51, 367-384.

Guillaumet, J. L.1987. Some structural and floristic aspects of the forest, Experientia, 43, 241-251.

Luizao, R. C. C., Luizao, F. J., Paiva, R. Q., Monteiro, T. F., Sousa, L. S., and Kruijt, B.2004. Variation of carbon and nitrogen cycling processes along a topographic gradient in a central Amazonian forest, Glob. Change Biol., 10, 592-600.

Oliveira, A. N. de, and Amaral, I. L. d.2004. Floristica e fitossociologia de uma floresta de vertente na Amazonia Central, Amazonas, Brasil, Acta Amazonica, 34, 21-34.

Oliveira, A. A. de, and Amaral, I. L. d.2005. Aspectos floristicos, fitossociologicos e ecologicos de um sub-bosque de terra firme na Amazonia Central, Amazonas, Brasil, Acta Amazonica, 35, 1116.

Ometto, J. P. H. B., Flanagan, L. B., Martinelli, L. A., Moreira,M. Z., Higuchi, N., and Ehleringer, J. R.2002. Carbon isotope discrimination in forest and pasture ecosystems of the Amazon Basin, Brazil, Glob. Biogeochem. Cy., 16(4), 1109, DOI:10.1029/2001gb001462.

Ometto, J. P. H. B., Ehleringer, J. R., Domingues, T. F., Berry, J. A., Ishida, F. Y., Mazzi, E., Higuchi, N., Flanagan, L. B., Nardoto, G. B., and Martinelli, L. A.2006. The stable carbon and nitrogen isotopic composition of vegetation in tropical forests of the Amazon Basin, Brazil, Biogeochemistry, 79, 251-274.


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