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Investigation:

ND-02 (Davidson / Stone / Markewitz / Carvalho / Sa / Vieira / Moutinho / Figueiredo)

LBA Dataset ID:

LBA_REE

Originator(s):

1. DAVIDSON, E.A.
2. DE CARVALHO, C.J.R.
      3. FIGUEIREDO, R.D.O.

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 results of a rainfall exclusion experiment in the Tapajos National Forest (Flona-Tapajos) at km 67 along the Santarem-Cuiaba BR-163 highway. From December 1999 through April 2005, following a one-year pre-treatment phase, rainfall was excluded from one of two 1-hectare plots of seasonally-dry humid tropical forest. Soil emissions of carbon dioxide (CO2), nitric oxide (NO), nitrous oxide (N2O), and methane (CH4) were monitored in order to determine the likely effect of increasingly frequent El Nino drought episodes in the Amazon basin. Soil trace gas flux data are provided in one comma-separated data file.

Beginning Date:

1998-09-10

Ending Date:

2005-04-10

Metadata Last Updated on:

2009-12-14

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 ND-02 Soil Gas Flux, Rainfall Exclusion, km 67, Tapajos National Forest:  http://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=955

Documentation/Other Supporting Documents:

LBA-ECO ND-02 Soil Gas Flux, Rainfall Exclusion, km 67, Tapajos National Forest:  http://daac.ornl.gov/LBA/guides/ND02_REE_Trace_Gas_Tapajos.html

Citation Information - Other Details:

Davidson, E.A., C.J.R. de Carvalho, R.O. Figueiredo 2009. LBA-ECO ND-02 Soil Gas Flux, Rainfall Exclusion, km 67, Tapajos National Forest. 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/955

Keywords - Theme:

Parameter Topic Term Source Sensor
CARBON DIOXIDE BIOSPHERE SOILS FIELD INVESTIGATION IR CO2 ANALYZER
METHANE BIOSPHERE SOILS FIELD INVESTIGATION GC-FID (GAS CHROMATOGRAPH/FLAME IONIZATION DETECTOR)
NITRIC OXIDES BIOSPHERE SOILS FIELD INVESTIGATION CHEMILUMINESCENCE
NITROUS OXIDE BIOSPHERE SOILS FIELD INVESTIGATION GC-ECD (GAS CHROMATOGRAPH/ELECTRON CAPTURE DETECTOR)

Uncontrolled Theme Keyword(s):  ALKALINITY, AMAZON, BIOGEOCHEMICAL CYCLES, BRAZIL, CAPOEIRA, CARBON, CARBON DIOXIDE, CH4, CHEMISTRY, CO2, CONDUCTIVITY, FLONA, FLORESTA NATIONAL TAPAJOS, LITTER LEACHATE, METHANE, N2O, NET N MINERALIZATION, NET NITRIFICATION, NITRIC OXIDE, NITROGEN, NITROGEN AVAILABILITY, NITROUS OXIDE, NO, NUTRIENT CYCLING, PARA, PH, PRECIPITATION, PRIMARY FOREST, SECONDARY FOREST, SLASH-AND-BURN AGRICULTURE, SOIL, SOIL GAS, SOIL WATER, TAPAJOS, THROUGHFALL, TOWER, TRACE GAS FLUXES

Keywords - Place (with associated coordinates):

Region
(click to view profile)
Site
(click to view profile)
North South East West
Pará Western (Santarém) km 67 Primary Forest Tower Site -2.85700 -2.85700 -54.95900 -54.95900

Related Publication(s):

Davidson, E.A., F.Y. Ishida, D.C. Nepstad. 2004. Effects of an experimental drought on soil emissions of carbon dioxide, methane, nitrous oxide, and nitric oxide in a moist tropical forest. Global Change Biology 10:718-730.

Nepstad, D.C., P. Moutinho, M.B. Dias, E. Davidson, G. Cardinot, D. Markewitz, R. Figueiredo, N. Vianna, J. Chambers, D. Ray, J.B. Guerreiros, P. Lefebvre, L. Sternberg, M. Moreira, L. Barros, F.Y. Ishida, I. Tohlver, E. Belk, K. Kalif, and K. Schwalbe. (2002) The effects of partial throughfall exclusion on canopy processes, aboveground production, and biogeochemistry of an Amazon forest. Journal of Geophysical Research-Atmospheres, Vol. 107, No. D20.

Data Characteristics (Entity and Attribute Overview):

Data Characteristics:

The file Soil_Trace_Gas_Emissions_Tapajos.csv is a comma-delimited file containing the means and standard errors of the 18 total trace gas emissions measurements per treatment (rainfall exclusion or control) per sampling date for the Flona Tapajos Rainfall Exclusion Site. For convenience, the Day of Year is also provided. The actual number of repetitions that were included in each mean/standard error is listed in the respective *_Reps columns. Treatment Status indicates whether the measurement was made before or after the rain exclusion went into effect. A -9999 has been listed wherever values are missing. Note that positive values indicate emissions from the soil to the atmosphere; negative values indicate net uptake by the soils of atmospheric gases.



Data File Description: Soil_Trace_Gas_Emissions_Tapajos.csv

Column Number Heading Description

1 Site Study Site: Flona-rainfall exclusion

2 Date Sample date (YYYY/MM/DD)

3 Day_of_Year Day of Year

4 Treatment_Status Treatment: pre-exclusion, post-exclusion

5 Treatment Treatment class: Exclusion, Control

6 CO2_Mean Carbon dioxide, mean

7 CO2_Std_Err Carbon dioxide, standard error

8 CO2_Reps Carbon dioxide, number of repetitions

9 CO2_Units Carbon dioxide, measurement units

10 NO_Mean Nitric oxide, mean

11 No_Std_Err Nitric oxide, standard error

12 NO_Reps Nitric oxide, number of repetitions

13 NO_Units Nitric oxide, measurement units

14 N2O_Mean Nitrous oxide, mean

15 N2O_Std_Err Nitrous oxide, standard error

16 N2O_Reps Nitrous oxide, number of repetitions

17 N2O_Units Nitrous oxide, measurement units

18 CH4_Mean Methane, mean

19 CH4_std_err Methane, standard error

20 CH4_Reps Methane, number of repetitions

21 CH4_Units Methane, measurement units



Example data record:



Site,Date,Day_of_Year,Treatment_Status,Treatment,CO2_Mean,CO2_Std_Err,CO2_Reps,CO2_Units,

NO_ Mean,No_Std_Err,NO_Reps,NO_Units,N2O_Mean,N2O_Std_Err,N2O_Reps,N2O_Units,

CH4_Mean,CH4_std_err,CH4_Reps,CH4_Units



FLONA-rainfall exclusion,1998/09/10,253,pre-exclusion,exclusion,0.14,0.01,18,g C/m2/h,

6.19,1.11,18,ng N/cm2/h,0.62,0.08,16,ng N/cm2/h,

-0.90,0.44,16,mg CH4/m2/d

FLONA-rainfall exclusion,1998/09/10,253,pre-exclusion,control,0.12,0.01,18,g C/m2/h,

3.93,0.47,18,ng N/cm2/h,0.61,0.10,17,ng N/cm2/h,

-0.36,0.61,17,mg CH4/m2/d

...

FLONA-rainfall exclusion,2005/04/12,105,post-exclusion,exclusion,0.10,0.02,18,g C/m2/h,

0.27,0.02,18,ng N/cm2/h,4.52,0.78,18,ng N/cm2/h,

-0.37,0.23,18,mg CH4/m2/d

FLONA-rainfall exclusion,2005/04/12,105,post-exclusion,control,0.09,0.01,18,g C/m2/h,

0.36,0.04,18,ng N/cm2/h,5.54,1.33,18,ng N/cm2/h,

-0.26,0.17,18,mg CH4/m2/d

Data Application and Derivation:

Changes in precipitation in the Amazon Basin resulting from regional deforestation, global warming, and El Nino events may affect emissions of carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and nitric oxide (NO) from soils. Changes in soil emissions of radiatively important gases could have feedback implications for regional and global climate. Here we report the final results of five year of a large-scale (1 ha) throughfall exclusion experiment, followed by one year of recovery with natural throughfall, conducted in a mature evergreen forest near Santarem, Brazil. The exclusion manipulation lowered annual N2O emissions in 4 out of 5 treatment years (a natural drought year being the exception), and then recovered during the first year after the drought treatment stopped.

Quality Assessment (Data Quality Attribute Accuracy Report):

Quality Assessment:

The quality of each flux measurement was vetted by the PI. Measurements were discarded if measured concentrations were outside of a reasonable range, or where the tracing of chamber concentrations was too erratic to reliably fit a slope.

Process Description:

Data Acquisition Materials and Methods:

Two 1 ha plots were identified from an initial survey of 20 ha of forest. A 1.5 m deep trench was excavated around the perimeter of the treatment plot to reduce the potential for lateral movement of soil water from the surrounding forest into the plot. A similar trench was excavated around the control plot to avoid the confounding of treatment and trenching effects. All measurements reported here were taken at least 20 m from the trench edge to guard against edge effects.



Plastic PAR-transmitting greenhouse panels were installed in the understory of the exclusion plot only for the duration of the rainy season. The panels were

installed such that small gaps were left around tree stems to allow in nutrient-rich stemflow. In all, about half of the annual rainfall was diverted from the exclusion plot. While they were in place, panels were flipped on their sides every two days to return any accumulated litter to the forest floor beneath.



Eighteen soil gas flux chambers were installed in each plot for a total of 18 CO2, NO, N2O, CH4 measurements per treatment.



Fluxes of nitric oxide (NO) and carbon dioxide (CO2) were measured in the field using dynamic chambers connected to a Scintrex LMA-3 chemiluminescent analyzer and a LiCor 6252 IRGA. Fluxes of N2O and CH4 were measured by filling syringes with gas from static chamber headspace at 10-minute intervals, and analyzing the samples in a laboratory using gas chromatography.

References:

Davidson, E.A., D.C. Nepstad, F.Y. Ishida, P.M. Brando. 2008. Effects of an experimental drought and recovery on soil emissions of carbon dioxide, methane, nitrous oxide, and nitric oxide in a moist tropical forest. Global Change Biology 14:2582-2590. DOI: 10.1007/s10533-008-9231-6



Verchot LV, Davidson EA, Cattanio JH, Ackerman IL (2000) Land use change and biogeochemical controls of methane fluxes in soils in eastern Amazonia. Ecosystems 3:41-56. doi:10.1007/s100210000009



Verchot LV, Davidson EA, Cattanio JH, Ackerman IL, Erickson HE, Keller M (1999) Land use change and biogeochemical controls of nitrogen oxide emissions from soils in eastern Amazonia. Global Biogeochemical Cycles 13:31-34. doi:10.1029/1998GB900019

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