uid=ARC,o=lter,dc=ecoinformatics,dc=org all public read 1994gsbflx.6 Arctic LTER Program Gus Shaver

Marine Biological Lab 7 MBL St. Woods Hole MA 02543 USA

Arctic LTER Program

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 arc_im@mbl.edu http://ecosystems.mbl.edu/ARC/ Jim Laundre

Marine Biological Lab 8 MBL St. Woods Hole MA 02544 USA

Associated Researcher 2000 Ecosystem-level Carbon dioxide fluxes were measured in two long-term experimental wet sedge tundra sites near Toolik Lake, AK. Experimental treatments at each site included factorial NxP, greenhouse and shade house and were begun in 1985 (Sag site) or in 1988 (Toolik sites). Fluxes were measured on quadrats that were later sampled for biomass and leaf area. Alaska biomass Carbon dioxide flux respiration productivity nitrogen phosphorus tundra. Acceptance and utilization of LTER data requires that: The Principal Investigator be sent a notice stating reasons for acquiring any data and a description of the publication intentions. The Principal Investigator of the data set be sent a copy of the report or manuscript prior to submission and be adequately cited in any resultant publications A copy of any resultant publications should be sent to: Principal Investigator Ecosystems Center Marine Biological Laboratory Woods Hole, MA 02543 http://ecosystems.mbl.edu/ARC/meta_template.php?FileName=./terrest/biomass/xlsfiles/1994gsbflx.html Toolik Lake(68 degrees 38'N, 149 degrees 34'W, elevation 760 m) (68 degrees 38N, 149 degrees 34W) North Slope, Alaska, U.S.A. -149.566666666667 -149.566666666667 68.6333333333333 68.6333333333333 Sagavanirktok River (68 degrees 46'N, 148 degrees 52'W, elevation 470 m) North Slope, Alaska, U.S.A. -148.866666666667 -148.866666666667 68.7666666666667 68.7666666666667 1994-07-24 1994-07-27 15Mar95 Separated comma delimited data from Excel file. JL 28Oct2004 Added units and precision to variable description section. JL Version2: Creaded Excel metadata form. Changed title and added attribut table. 10Jan06 JimL Version 3: Added LTERNET Data Access server proxy for Excel and comma delimited data files. Version 4: Upadte LTERNET Data Access server proxy link for Excel and comma delimited data files. Changed from knb to das in url. Version 5: Updated the metadata form to new version and eml to 2.1.0 JimL 9Jul2012 Version 6: Updated metadata to newer form (with sites sheet). Ch March 2013. Data Manager

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 arc_im@mbl.edu http://ecosystems.mbl.edu/ARC/ ARC LTER

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 arc_im@mbl.edu http://ecosystems.mbl.edu/ARC/ Plots were setup as indicated below, with annual fertilization treatments of 10 g/m2 Nitrogen (as NH4NO3) and 5 g/m2 Phosphorous (as triple superphosphate). Greenhouses and shadehouses were annually set up in late May or early June and removed in the end of August or early September. Sites: Block 1 - Toolik Inlet (CT, N, P, NP, GH, GHNP, and Shade treatment codes) Indicated as "Block 1" Treatments began summer of 1989; one 5x10m plot/treatment Block 2 - Toolik Outlet (Same treatments) "Block 2" Treatments began summer of 1989; one 5x10m plot/treatment Calculations: Units: Tissue mass data are expressed in g/quadrat (400 cm2). Multiply by 25 to get g/m2. Leaf blade area is in cm2/quadrat. Multiply by .0025 to get m2 leaf/m2 ground. Sampling Description. Biomass quadrats, size 20x20 cm, were randomly located along line transects within plots. There were 4 quadrats/plot (treatment) collected in Blocks 1 and 2. All aboveground biomass plus belowground stems and rhizomes were clipped in 20x20 cm quadrats. Ecosystem-level CO2 fluxes were measured on 3 of the 4 quadrats using a LiCor 6200 Portable Photosynthesis System. A custom-made clear Plexiglas cuvette (30x30 cm surface area x 30 cm high) was placed directly over the quadrat to be sampled using the standing surface water as a seal. A standard depth was used to keep the chamber volume constant. After allowing the LiCor system to stabilize for a few seconds, 10 consecutive observations of the average CO2 flux over 20 second intervals were made. The last 6 of the 10 observations were then averaged for use as the flux measurement. Air temperature, photosynthetically active photon flux, and CO2 concentration inside the cuvette were also recorded with each observation. All flux measurements were made on a warm sunny day (26 July 1994) between 11:00 AM and 3 PM Alaska Daylight time. The cuvette was then removed briefly to allow air temperatures and CO2 concentrations to recover before being shaded with an opaque blanket for ecosystem respriation. During the unshaded measurements photon flux inside the cuvette varied from 600-2000 microE m-2 sec-1, but most measurements were made between 950-1200 micro E m-2 sec-1. Photon flux during the unshaded measurements were always less than 10 micro E m-2 sec-1, usually zero. Air temperatures were between 18o and 28o C, with most measurements made between 20o and 24o C. Concentration of CO2 inside the cuvette was 330-440 ppm, with most measurements made at 340-350 ppm. In presenting our results, we use the unshaded (full sunlight) CO2 flux measurement as our measure of Net Ecosystem Production, or NEP. Ecosystem Respiration, or RE, is the measurement made in the darkened cuvette. Gross Ecosystem Production (=Gross Ecosystem Photosynthesis), or GEP, is the difference between NEP and RE. In this presentation, negative values represent CO2 losses to the atmosphere (RE is always negative), and positive values represent CO2 inputs (GEP is always positive). See 1994gswsbm.txt for information on the biomass collection. pers-1 John Hobbie

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 jhobbie@mbl.edu Lead PI Gus Shaver

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 gshaver@mbl.edu Lead PI Jim Laundre

The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole MA 02543 USA

(508) 289 7496 arc_imr@mbl.edu Information Manager The goal of Arctic LTER project is to predict the future ecological characteristics of the site based upon our knowledge of the controls of ecosystem structure and function as exerted by physical setting and geologic factors, climatic factors, biotic factors, and the changes in fluxes of water and materials from land to water. To achieve this goal the Arctic LTER uses several approaches: Long-term monitoring and surveys of natural variation of ecosystem characteristics in space and time. Includes: climate, plant communities and productivity, thaw depth, stream flow, chemistry of streams and lakes, temperatures of streams and lakes, lake chlorophyll lake productivity, zooplankton abundance. Experimental manipulation of ecosystems for years and decades. Includes: tundra warming, shading, and fertilizing, grazer exclusions, fertilization of lakes and streams, addition and subtraction of predators. Synthesis of results and predictive modeling at ecosystem and watershed scales. Includes: stream N cycling, lake physics, bioenergetics of fish populations, water movement and transfer of DOC and nutrients from land to water, soil respiration, cycling and storage of C in tundra under different scenarios of future climates. This material is based upon work supported by the National Science Foundation under Grants #DEB-981022, 9211775, 8702328; #OPP-9911278, 9911681, 9732281, 9615411, 9615563, 9615942, 9615949, 9400722, 9415411, 9318529; #BSR 9019055, 8806635, 8507493. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. The Arctic LTER research site (68°N and 149°W) is in the foothills region of the North Slope of Alaska and includes the entire Toolik Lake watershed and the adjacent watershed of the upper Kuparuk River, down to the confluence of these two watersheds. This area is typical of the northern foothills of the Brooks Range, with continuous permafrost, no trees, a complete snow cover for 7 to 9 months, winter ice cover on lakes, streams, and ocean, and cessation of river flow during the winter. Tussock tundra vegetation of sedges and grasses mixed with dwarf birch and low willows form the dominant vegetation type with areas of drier heath tundra on ridge tops and other well-drained sites as well as areas of river-bottom willow communities. -149.75 -149.0433 68.8 68.5 610 1360 meter 1994gsbflx.csv Ecosystem-level Carbon dioxide fluxes in two long-term experimental wet sedge tundra sites near Toolik Lake, AK, ARC LTER 1994. 1994gsbflx.csv 1 \r\n column , " http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-arc.1380&urlTail=terrest/biomass/data/1994gsbflx.csv Label Label Quadrat label - First two characters= block number. Next characters = treatment code + rep. no. Quadrat label - First two characters= block number. Next characters = treatment code + rep. no. Leaf Area Leaf Area Leaf area centimeterSquaredPerFourHundredthMeterSquared real LAIm2_m2 LAIm2_m2 Leaf area in m2/m2 (leaf area * (10,000/400)/10,000) meterSquaredPerMeterSquared real IPAR IPAR Avg QNTM * (1-e^(-0.8*Leaf Area)) dimensionless real Blade wt Blade wt Weight of leaf blade gram real Leaf_culm wt Leaf_culm wt Ratio of leaf blade wt to culm wt dimensionless real Above wt Above wt Total aboveground plant biomass gram real Total wt Total wt Total biomass gram real Above(vasc) Above(vasc) Biomass of vascular plants gram real NEP NEP Net Ecosystem Production - full sunlight CO2 flux micromolePerMeterSquaredPerSecond real Resp Resp Ecosystem Respiration - darken CO2 flux micromolePerMeterSquaredPerSecond real GEP GEP Gross Ecosystem Production - (NEP - Resp) micromolePerMeterSquaredPerSecond real Avg QNTM Avg QNTM Average photon flux inside the cuvette micromolePerMeterSquaredPerSecond real Avg TAIR Avg TAIR Average air temperature inside the cuvette celsius real Avg CO2 Avg CO2 Average CO2 concentration inside the cuvette partPerMillion real 42 1994gsbflx.xls An excel file that has worksheets with the metadata and data. 1994gsbflx.xls Microsoft Excel http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-arc.1380&urlTail=terrest/biomass/xlsfiles/1994gsbflx.xls Microsoft Excel file Leaf area in square centimeter per .04 square meter of ground Leaf area in square meter per square meter of ground micro Einsteins (1E-06 moles of photons) per square meter per second (radiant flux density) ratio of two quantities as parts per million (1:1000000)