Summary:
Productivity of an ephemeral desert grassland was determined at the Badkhyz Nature Reserve Station in southern Turkmenistan, between 1948 and 1982. Monthly dynamics of above-ground plant biomass were made during the growing season (January-May) from 1948 to 1963, and the record of peak live biomass continues until 1982, with a gap from 1973 to 1976. These data are part of a series of grassland data sets recently assembled and checked by Dr. Tagir Gilmanov. These data cover a wide range of climate and "continentality" (increasing maximum summer temperatures, decreasing precipitation) from the North-West to the South-East of the Commonwealth of Independent States (former USSR).
Climate data for this site are also available: see Any Other Relevant Information in section 11 of this document.
More information on the entire Net Primary Production Project can be found at the NPP homepage.
Table of Contents
- Data Set Overview
- Investigator(s)
- Theory of Measurements
- Equipment
- Data Acquisition Methods
- Observations
- Data Description
- Data Organization
- Data Manipulations
- Errors
- Notes
- Application of the Data Set
- Future Modifications and Plans
- Software
- Data Access
- Output Products and Availability
- References
- Glossary of Terms
- List of Acronyms
- Document Information
1. Data Set Overview:
Data Set Identification:
NPP Grassland: Badkhyz, Turkmenistan, 1948-1982
Introduction:
The Badkhyz study site (35.68 N 62.0 E) is situated near Kushka in southern Turkmenistan. It is typical of the emphemeroidal ecosystems found on the serozem soils in the foothills of the mountains of Middle Asia. The climate of the region is characterized by the marked seasonality of precipitation, which occurs only in winter/early spring, giving an early and short growing season, followed by prolonged drought from May to October.
Long-term observations on climate, soils and productivity of this ecosystem have been published by Nechaeva et al. (1971), Artykov (1975), and Kamelin and Rodin (1989).
Objective/Purpose:
Data on biomass dynamics and productivity were recently assembled and checked as part of a series of grassland data sets covering a wide range of climate and "continentality" (increasing maximum summer temperatures, decreasing precipitation) from the North-West to the South-East of the Commonwealth of Independent States (Gilmanov
et al., 1996).
Summary of Parameters:
There are seven (7) parameters for this dataset. Items 1 and 2 refer to the site and the treatment of the site. Items 3, 4, 5, and 6 indicate the date of data collection. 1. Site 2. Treatment 3. Year 4. Month 5. Day 6. Date in decimal year 7. Above ground biomass
Discussion:
Peak live biomass measurements are available from 1948 to 1972, and 1977 to 1982, with a high inter-annual variation in climate regime. More detailed monthly data is available, restricted to growing season only, from 1948 to 1963.
Related Data Sets:
NPP data from other
grassland sites are available elsewhere in this archive.
Summary tables containing site characteristics and metadata for all the grassland sites are also available.
2. Investigator(s):
Investigator(s) Name and Title:
Dr. N.T. Nechaeva, Dr. S.Ya. Prikhod'ko and Dr. K.F. Shuravin
Title of Investigation:
Determination of net primary productivity of a desert steppe at Badkhyz, Turkmenistan.
Contact Information:
Dr. T.G. Gilmanov
Center for Ecology and Productivity of Forests
Russian Academy of Sciences
69 Novocheryomushkinskaya
Moscow 117418
RUSSIA
c/o Department of Biology and Microbiology
South Dakota State University
Brookings, SD 57007
U.S.A.
Telephone (U.S.A.): +1 (605) 688-4925/6141
Fax (Russia): +7 (095) 200-2216/2217 (Attn. Gilmanov 002840)
Fax (U.S.A.): +1 (605) 688-6677
Email: Tagir_Gilmanov@sdstate.edu
3. Theory of Measurements:
Net primary production (NPP), sensu stricto, is the total photosynthetic gain (less respiratory losses) of vegetation per unit ground area. For a given period, this is equal to the change in plant mass plus any losses due to death and decomposition, measured for both above ground and below ground plant parts. Earlier estimates of grassland NPP were based on peak standing dry matter only, and the studies of the International Biological Programme (IBP) in the late 1960s and early 1970s were based mainly on above-ground biomass changes, with few estimates of below-ground production.
Peak above-ground live biomass (or in some cases, the difference between maximum and minimum biomass) has been used as an estimate of net primary production - usually where only one or two measurements per year are available. Sometimes a conversion factor has been applied to take account of estimated turnover and the estimated ratio of above-ground to below-ground dry matter.
The "IBP Standard Method" of Milner and Hughes (1968) assumes that where live biomass increases between successive samples, production equals this increase; where biomass decreases or remains the same, production is assumed to be zero. Annual production is then obtained by summing the estimates for each sample interval.
Essentially, this method was used for the IBP synthesis by Singh and Joshi (1979), in particular for their estimates of below-ground production. A modified method was used for above-ground production, determined by a decision matrix (Singh et al., 1975); where increments in live biomass coincided with increases in standing dead matter, the latter were added to the monthly production.
The limitations of the above methods are discussed in detail by Long et al. (1989). In particular, the peak biomass method and variations on the IBP method underestimate production by not accounting for simultaneous growth and death. This may be significant in temperate grasslands with a long growing season, and is particularly a problem in tropical grasslands where the growing season may extend over much of the year. Some limited overestimation may occur by not accounting for periods of negative NPP (due to stress, or translocation between above and below ground plant parts) but underestimation of root turnover is probably the largest source of error. Long et al. (1989) estimated NPP for three terrestrial tropical grassland sites by summing monthly changes in live biomass plus losses due to death and decomposition for above and below ground vegetation. Monthly losses were determined as the change in dead matter plus the estimated disappearance of dead matter through decomposition. Dead matter disappearance was calculated each month as the product of relative decomposition rate and mean amount of dead matter.
Although some correlation between estimates obtained using different methods has been reported (Singh et al., 1975), the degree of underestimation may be strongly site-specific (Linthurst and Reimold, 1978; Long and Mason, 1983). Where sufficient data are available for a given grassland site, it may be possible to estimate NPP according to the different methods for the purposes of comparison. This may involve entry of data into algorithms or a spreadsheet containing these algorithms.
Methodological aspects of field experimental studies of biomass and production of grassland ecosystems in the Commonwealth of Independent States (former USSR) were summarized by Titlyanova (1988). The methods of field measurements of above-ground and below-ground biomass in Russian grasslands are based on the harvest technique and with respect to sampling area, replication, etc., are very close to the methods used by western ecologists during the IBP studies (e.g. Milner and Hughes, 1968; Sims and Coupland, 1979). The Russian approach to estimation of the annual production of grassland plant communities (with subdivision on aboveground and belowground components) is based on a calculation procedure utilizing data of repeated (usually 2-weekly) sampling during the season of live, standing dead and litter fractions of phytomass. This method of calculation gives the estimates of production which are 1.6 to 2.0 times higher than the seasonal maximum of the standing crop of the corresponding phytomass fraction (Titlyanova, 1988).
4. Equipment:
Sensor/Instrument Description:
- laboratory balance
- quadrat sampling frame
Collection Environment:
Ground level
Platform/Source:
Field investigation
Platform/Source Mission Objectives:
Determination of net primary productivity
Key Variables:
Above-ground live biomass
Principles of Operation:
See "3. Theory" Above
Sensor/Instrument Measurement Geometry:
Not Applicable
Manufacturer of Sensor/Instrument:
Information Not Available
Calibration:
Not Applicable
5. Data Acquisition Methods:
Refer to literature or Principal Investigator/ Contact for details
6. Observations:
Data/Field Notes:
Contact Principal Investigator (see 2. above) for details of any peculiar conditions at the time of data collection
site elevation (m): 700
mean annual precipitation (mm): 266
mean monthly min temperature (C): -14.7 (Jan)
mean monthly maximum temperature (C): 41.2 (July)
vegetation type: desert steppe
dominant species: Poa bulbosa (C3? photosynthetic types)
historical long-term management regime (estimated): NOT KNOWN
maximum aboveground live biomass (typical month): 69 g/m2 (May)
soil type: serozem, light loam
soil pH: 8.0
soil texture (sand/silt/clay): 0.68/ 0.23/ 0.15
soil carbon content: 1160 g/m2 (0-20 cm)
soil nitrogen content: 140 g/m2 (0-20 cm)
7. Data Description:
Spatial Characteristics:
Spatial Coverage:
Study site located at 35.68 N, 62.0 E
Spatial Coverage Map:
Not Available
Spatial Resolution:
Not Applicable
Projection:
Not Applicable
Grid Description:
Not Applicable
Temporal Characteristics:
Temporal Coverage:
January 1948 to May 1982. Preview data set to check for data gaps, missing values, etc.
Temporal Coverage Map:
Not Applicable
Temporal Resolution:
One month
Data Description:
There are seven (7) parameters for this dataset. Items 1-2 refer to the site and the treatment of the site. These items are referred to as coded variables.
1.
variable=Site
definition=site where data were gathered
code=bdk: Badkhyz
2.
variable=Treatmt
definition=long term management of site
code=lngtrm: data not available
3.
variable=Year
definition=year in which data were collected
units=year
minimum=1948
maximum=1982
4.
variable=Mn
definition=month in which data were collected
units=month
minimum=01
maximum=05
5.
variable=Dy
definition=day in which data were collected
units=day
minimum=01
maximum=15
6.
variable=Tyear
definition=Date in decimal year
units=year plus the Julian date divided by 365
minimum=1948.041
maximum=1982.332
7.
variable=AGbiomass
definition=above ground biomass
units=[g][m^-2]
minimum=0
maximum=172
Sample Data Record:
Site Treatmt Year Mn Dy Tyear AGbiomass
------------------------------------------------------
bdk lngtrm 1948 01 15 1948.041 5.0
8. Data Organization:
Data Granularity:
The data file associated with the Badkhyz Grassland is listed below.
1. Data File bdk_npp.txt 4.7 KBytes
Period: 01 Jan 1948 through 01 May 1982
Latitude: 35.68N, Longitude: 62E
A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary.
Data Format:
The dataset is an ASCII file. The first 18 lines are metadata; data records begin on line 19. The variable values are delimited by semi-colons. The value -999.9 is used to denote missing values.
Site;Treatmt;Year;Mn;Dy;Tyear;AGbiomass [units g/m2]
bdk;lngtrm ;1948;01;15;1948.041; 5.0
bdk;lngtrm ;1948;02;15;1948.126; 7.0
9. Data Manipulations:
Formulae:
Derivation Techniques and Algorithms:
Algorithms and/or software available for calculating NPP from data sets using different methods are not currently available.
Data Processing Sequence:
Information Not Available
Calculations
NPP Data Dictionary
Graphs and Plots
Information Not Available
10. Errors:
Information Not Available
11. Notes:
Limitations of the Data:
Net primary production of grasslands is subject to a number of different methods of estimation from biomass data, some of which may be inappropriate for particular biome types. Methodology of estimation/calculation needs to be taken into account, as well as methodology of measurement, when making comparisons between different regions. Errors in biomass measurement may also occur between different study sites. For short time series of data it may be assumed that measurement methodology remains consistent; however, over very long time series changes in staff, tools, etc. may lead to "calibration" errors.
Known Problems with the Data:
Information Not Available
Usage Guidance:
See "Limitations of the Data" above
Any Other Relevant Information About the Study:
Monthly climate data from 1941 to 1982 (monthly maximum and minimum temperature and monthly rainfall) are available for this study site in the file
/data/npp/grassland/comp/bdk_cli.txt">bdk_cli.txt.
12. Application of the Data Set:
Data on net primary production of particular ecosystem types worldwide is in demand from modellers working at a variety of scales from Global Climate Models (GCMs) to regional or national estimates of carbon fluxes between atmosphere, biosphere and soils. Ground-based data are also required for calibration of remote sensing measurements, and parameterisation and validation of models based on remote sensing.
13. Future Modifications and Plans:
Refer to Principal Investigator for details of continuing data collection.
14. Software:
Software Description:
Utility software is planned to available for (i) generating quasi-real daily/hourly climate data from the monthly data; (ii) calculating NPP from data sets using different algorithms, crude root/shoot ratios, etc.
Software Access:
Not Yet Available
15. Data Access:
Contact Information:
ORNL DAAC User Services Office
Oak Ridge National Laboratory
Telephone: +1 (865) 241-3952
Email Address: ornldaac@ornl.gov
Data Center Identification:
ORNL Distributed Active Archive Center
Oak Ridge National Laboratory
Telephone: +1 (865) 241-3952
Email Address: ornldaac@ornl.gov
Procedures for Obtaining Data:
Users may place requests by telephone, electronic mail, or FAX. Data are also available via the World Wide Web at
">http://
Data Center Status/Plans:
NPP data may be ordered from the ORNL DAAC. Please contact the ORNL DAAC User Services Office for the most current information about these data and how to order them.
16. Output Products and Availability:
Available on-line, as computer FTP file (zipped or unzipped), on CDs, or on IBM-formatted diskettes.
17. References:
Artykov, K. (1975) Agroclimatic foundations of the phytomeliorative works in the foothills of Turkmenistan. Ashkhabad, 101 pp. (In Russian). Gilmanov, T.G., W.J. Parton and D.S. Ojima (1996) Testing the CENTURY ecosystem level model on data sets from eight grassland sites in the former USSR representing a wide climatic/soil gradient. Ecological Applications (in press).
Kamelin R.V. and L.E. Rodin, eds. (1989) Pistacea woodlands of Badkhyz. (In Russian). Nauka, Leningrad. 246 pp.
Linthurst, R. and R.J. Reimold (1978) An evaluation of methods for estimating the net primary production of estuarine angiosperms. J. Applied Ecology 15, 919-932.
Long, S.P. and Mason, C.F. (1983) Saltmarsh Ecology. Blackie, Glasgow.
Long, S.P., E. Garcia Moya, S.K. Imbamba, A. Kamnalrut, M.T.F. Piedade, J.M.O. Scurlock, Y.K. Shen and D.O. Hall (1989) Primary productivity of natural grass ecosystems of the tropics: a reappraisal. Plant and Soil 115, 155-166.
Milner, C. and R.E. Hughes (1968) Methods for the Measurement of the Primary Production of Grassland. IBP Handbook No.6. Blackwell, Oxford.
Nechaeva N.T., S.Ya. Prikhod'ko and K.F. Shuravin (1971) Harvest formation on the Poa-Carex pastures of the foothills of Central Asia in relation to meteorological conditions (as exemplified by Badkhyz, Turkmenian Republic). In: Biokompleksy pustyn' i povyshenie ikh produktivnosti. Ylym, Ashkhabad. p. 71-113. (In Russian).
Nechaeva, N. T., S. Ya Prikhod'ko, and K. F. Shuravin. 1971. Net Primary Production for Badkhyz (Turkmenistan) Grassland Site Dataset, In Nechaeva N.T., S.Ya. Prikhod'ko and K.F. Shuravin (1971) Harvest formation on the Poa-Carex pastures of the foothills of Central Asia in relation to meteorological conditions (as exemplified by Badkhyz, Turkmenian Republic). In: Biokompleksy pustyn' i povyshenie ikh produktivnosti. Ylym, Ashkhabad. p. 71-113. (In Russian).
Sims, P.L. and R.T. Coupland (1979) Producers. In: Grassland ecosystems of the world: analysis of grassland and their uses (ed. R.T. Coupland). Cambridge University Press. pp. 49-72.
Singh, J.S. and M.C. Joshi (1979) Tropical grasslands primary production. IN: Grassland Ecosystems of the World (R.T. Coupland, ed.) Cambridge University Press. pp. 197-218.
Singh, J.S., W.K. Lauenroth and R.K. Sernhorst (1975) Review and assessment of various techniques for estimating net aerial primary production in grasslands from harvest data. Botanical Review 41, 181-232.
Titlyanova, A.A. (1988) Methodology and methods of studying of the production-destruction processes in herbaceous ecosystems, In: Biologicheskaya produktivnost' travyanykh ecosistem [Biological productivity of herbaceous ecosystems] (V.B. Ilyin, ed.). Nauka, Novosibirsk (In Russian). pp. 3-10.
18. Glossary of Terms
A general glossary for the DAAC is located at http://cdiac.esd.ornl.gov/cdiac/glossary.html.
A glossary of EOSDIS terms is available at http://wist.echo.nasa.gov//v0ims/glossary.of.terms.html.
19. List of Acronyms:
A general list of acronyms for the DAAC is available at
http://cdiac.esd.ornl.gov/cdiac/pns/acronyms.html.
The EOSDIS Acronym and Abbreviation List is located at http://wist.echo.nasa.gov//v0ims/acronyms.html
20. Document Information:
December 10, 1997 (data citation revised on September 23, 2002)
Review Date:
January 15, 1998
Document ID:
ORNL-NPP_BDK
Citation:
Gilmanov, T. G. 1998. NPP Grassland: Badkhyz, Turkmenistan, 1948-1982. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
Document Curator:
webmaster@www.daac.ornl.gov
Document Author:
Dr. J. M. O. Scurlock
Document URL:
http://daac.ornl.gov