Total Soil Respiration Data at the Hubbard Brook Experimental Forest, 1998-2002
TITLE
Total Soil Respiration Data at the Hubbard Brook Experimental Forest, 1998-2002
PRINCIPAL INVESTIGATOR(s)
Tim Fahey
Department of Natural Resources, Cornell University
104A Bruckner Hall
Ithaca, NY 14853
USA
OTHERS INVOLVED
Cindy Wood
Suzanne Wapner
ABSTRACT:
Total soil respiration – or the emission of CO2 from soil – was measured monthly for five years (1998-2002) at several sites in the reference forest. These data allow the estimation of C flux from soil to atmosphere. These estimates are described in detail in Fahey et al. (2005). Monitoring was discontinued with the intention of repeating the measurements if and when major changes in biota and environment on the plots occurred.
KEYWORD SET: Hubbard Brook Ecosystem Study LTER
carbon, carbon dioxide, carbon flux, HBEF Bear Brook Watershed, HBR, Hubbard Brook LTER, respiration, soil.
BEGIN DATE
1998
END DATE
2002
LOCATION
Bear Brook Watershed (west of Watershed 6).
West bounding coordinate: -71.743462
East bounding coordinate: -71.735649
North bounding coordinate: 43.957001
South bounding coordinate: 43.949928
Watershed 1
West bounding coordinate: -71.730866
East bounding coordinate: -71.725832
North bounding coordinate: 43.959356
South bounding coordinate: 43.952121
LOCATION DESCRIPTION
West of WS6: Soil collars for TSR measurement are co-located with litterfall collectors, generally about 2 m upslope, and TSR collars are given the same numbers in this database as corresponding litter traps. Twelve collars are sampled at each of four sites in the Bear Brook study area west of WS6: Bear Brook lower – southwest of WS6 weir, @ 525 m elevation; Bear Brook mid – west of WS6 @ 585 m elevation; Bear Brook high – west of rain gauge 9 @ 800 m elevation; Bear Brook (throughfall site) spruce-fir – south of WS6 trail @ 790 m elevation
Within WS1, TSR collars are co-located with the litterfall collectors (~2 m upslope) and numbered to correspond with litter collector numbers. Twelve collars are sampled at each of four sites in WS1: WS1 low – corresponds to Lysimeter Site 6 @ 560 m elevation; WS1 mid – corresponds to Lysimeter Site 4 @ 650 m elevation; WS1 high – corresponds to Lysimeter Site 3 @ 750 m elevation; WS1 spruce-fir – corresponds to Lysimeter Site 2 @ 770 m elevation
SAMPLING DESIGN
The location of the eight plots (four each in Bear Brook (west of WS6) and WS1) were chosen to stratify the sampling by elevation. These sites are co-located with the sampling for litterfall, fine root biomass, soil solutions, microbial biomass and microarthropods. Within site collars are positioned randomly.
DATA DESCRIPTION
Twelve permanent soil collars were positioned randomly in each plot; the collars minimized disruption of the forest floor during measurements while maintaining a tight seal. Measurements were conducted on 23 dates during the snow-free season (May-November) over 5 years (1998-2002), for a total of 2100 flux measurements. Precautions were taken to reduce bias in these measurements of FCO2 (Davidson et al. 2002). The CO2 concentration was measured in the ambient air adjacent to the collar. Then, the chamber was placed over the collar and allowed to equilibrate for about 1 min. Over the interval of three or four flux readings, the concentration of CO2 in the headspace of the chamber spanned a range from about 40 Ámol•mol-1 below to about 60 Ámol•mol-1 above the ambient atmospheric concentration near the soil surface, and the average of these three or four readings was used. Soil temperature was measured to ▒0.5 ░C at 5 cm soil depth using a soil probe for each reading. For a few dates when instrument failure occurred, soil temperature data were derived from thermistor measurements made in association with a soil-freezing study, as detailed by Hardy et al. (2001).
To simplify scaling to the plot and watershed scale all TSR flux values in this data set have been corrected for average plot-level coverage values of boulders and tree root crowns, assuming that TSR was zero for these locations which were not sampled. These coverage values were obtained in each plot using the line intercept method (Canfield 1941) and measured tree basal area, as reported in Fahey et al. (2005). Hence, the values of TSR (micromoles of C per meter2 per second) are lower than the actual field measured values by a constant proportion for each plot. The rock/bole corrections for each plot are: BB low, 11.0%; BB mid, 7.9%; BB high, 10.4%; BB s/f, 5.8%; WS1 low, 8.6%; WS1 mid, 6.8%; WS1 high, 33.8%; WS1 SF, 39.5%
LABORATORY PROCEDURES
Soil CO2 emission (TSR) was measured using a LI-COR soil respiration chamber (model LI-6000-09) (LI-COR Biosciences, Lincoln, Nebraska) and LI-6200 infrared gas analyzer (LI-COR Biosciences, Lincoln, Nebraska) (Norman et al. 1992).
DATA ACCESS GUIDELINES
Data Use Policy



The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. Permission to use this dataset is granted to the Data User free of charge subject to the following terms:

1) Acceptable use. Use of the dataset will be restricted to academic, research, government or other not-for-profit professional purposes.

2) Redistribution. The data and metadata are provided for use by the Data User. The Data User will not redistribute the original Data Set or metadata to others without the explicit permission of the Principal Investigator.

3) Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly attribute the Data Set in any publications or in the metadata of any derived data products that were produced using the Data Set. Citation should take the following general form: Creator, Year of Data Publication, Title of Dataset, Publisher, Dataset identifier.

Citation example: Holmes, R.T. 2012. Bird Abundances at Hubbard Brook (1969-2010) and on three replicate plots (1986-2000) in the White Mountain National Forest. Durham, NH. Hubbard Brook Data Archive [Database]. http://hubbardbrook.org/data/dataset.php?id=81 (23 July 2012)

4) Acknowledgment: The Data User should acknowledge any institutional support or specific funding awards referenced in the metadata accompanying this dataset in any publications where the Data Set contributed to its content. Acknowledgments should identify the supporting party, the party that received the support, and any identifying information such as grant numbers.

Acknowledgment example: Data on [topic] were provided by [name of PI] on [date]. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station, Newtown Square, PA. Significant funding for collection of these data was provided by [agency]-[grant number], [agency]-[grant number], etc.

5) Consultation and questions. Data users are strongly encouraged to consult with the Principal Investigator(s) who collected these data for further information. Also, when appropriate, Data Users should consider including the Principal Investigator as a collaborator and/or co-author in the use of these data.

6) Notification. The Data User will notify the Principal Investigator of any publication or derivative work based on the Data Set. The Data User will also provide the Principal Investigator and/or the administrator of the Hubbard Brook Ecosystem Study with a pdf or two reprints of any publication(s) resulting from use of the Data Set.

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CONTACT PERSON

Information Manager, Hubbard Brook LTER
234 Mirror Lake Road
North Woodstock, NH 03262
USA

Phone: (603) 726-8902
Email: hbr-im@lternet.edu

Data file: soil_resp.txt
Description: Total soil respiration data collected at the Bear Brook reference watershed, Hubbard Brook LTER, 1998 - 2002
Notes on Data: The data are physically located at the Fahey Lab, Cornell University, Ithaca NY
ColumnVariableDescriptionUnitsCoded?Missing value label
1SITESite/Watershednoneynone
2ELEVElevationnoneynone
3YEARYearYYYYnnone
4DATESample dateYYYY-MM-DDnnone
5COLLARCollar ID numbernoneynone
6 SOILRESP Total soil respiration micromolePerSquareMeterPerSecondnnone
7 SOILT5C Soil temperature at 5 cm depth celsiusnnone

CODES

Variable: SITE
Code
Description
bear_brook
Bear Brook Watershed West of WS6
WS1
Watershed 1
Variable: ELEV
Code
Description
High
High elevation site
Low
Low elevation site
Mid
Mid elevation site
Low
Low elevation site
S/F
Spruce-fir site
Variable: COLLAR
Description:
Collar number