uid=ARC,o=lter,dc=ecoinformatics,dc=org all public read 2012_GS_ITEX_PF_CHN_Data.02 Arctic LTER Program Gaius Shaver

Ecosystems Center at the Marine Biological Laboratory 7 MBL Street Woods Hole MA 02543 United States

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/ Edward Rastetter

Ecosystems Center at the Marine Biological Laboratory 7 MBL Street Woods Hole MA 02543 United States

Associated Researcher Mathew Williams

University of Edinburgh School of Geosciences Darwin Building Edinburgh EH9 EJU United Kingdom

Associated Researcher James Laundre

Ecosystems Center at the Marine Biological Laboratory 7 MBL Street Woods Hole MA 02543 United States

Data Manager Laura van der Pol

Ecosystems Center at the Marine Biological Laboratory 7 MBL Street Woods Hole MA 02543 United States

Field Crew 2013 The percent carbon and nitrogen from leaves of shoots harvested from 1m x 1m point frame plots the summer of 2012 at Toolik Lake, Alaska. were measured on a ThermoScientific 2000. For each point frame plot, six shoots were harvested from upper, middle, and low sections of the canopy. The photosynthetic capacity of each shoot was analyzed with a LiCor 6400 infra-red gas analyzer by being run through a light response and A/Ci curve. The area of the shoot as viewed from the stop of the LiCor opaque, confer chamber ("silhouette area") as well as the area of each shoot organ type was measured. These data are published separately, though methods are described below. shoot photosynthesis shrub canopy point frame percent carbon percent nitrogen CHN Analysis 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/tracegas/xlsfiles/2012_GS_ITEX_PF_CHN_Data.html Upland site; co-located in Block 1 of the Shrub LTER sites; IVO 68° 38'18.8" N, 149° 34' 07.2" W +/- 50m. Except for plots marked "FERT", plots are outside of the designated LTER treatments, though are exposed to the same environmental conditions. All plots were chosen by the dominant shrub canopy (either Salix pulchraor Betula nana) and preferentially selected to be 90cm+ in height. -149.568666666666 -149.568666666666 68.6385555555555 68.6385555555555 Outlet site; co-located in Block 2 of the Shrub LTER sites; IVO 68° 38'008.1" N, 149° 35' 017.1" W +/- 50m. Except for plots marked "FERT", plots are outside of the designated LTER treatments, though are exposed to the same environmental conditions. All plots were chosen by the dominant shrub canopy (either Salix pulchraor Betula nana) and preferentially selected to be 90cm+ in height. -149.588083333333 -149.588083333333 68.6355833333333 68.6355833333333 2012-06-23 2012-08-07 Organisms Studied Genus Betula Species nana Genus Salix Species pulchra Genus Salix Species glauca This was a season-long project, though it followed similar methods to ITEX projects performed starting in 2003 that are likely to be replicated in the future for reasearch at the Toolik Field Station, AK. Updated Metadata sheet Version 2: Updated metadata to newer version (with sites sheet). CH April 2013. Version 3: Corrected eml excel file name wrong extension. JimL 16May13 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/ HARVEST METHOD: The methods for setting up each point frame plot are described in both the "PinDropData" and "PF_LAI" datasets. The methods here describe how each shoot was harvested from the plots which were used for the point frame method. Six shoots were harvested from each of 19 1m x 1m point frame plots which were dominated either by Salix pulchra or Betula nana tall, shrub species. The "shoots" described here are branch clippings between eight to ten inches long. Whenever possible they were selected for appearing relatively healthy, intact leaves, and each shoot was taken from a different plant. As these shoots were used for shoot-level and leaf-level measurements, shoots with bi-furcated stems -- or two stems from the same branch/height were cut -- one for leaf-level and the second for shoot-level analyses. Before being cut, we measured the distance from the point frame to the highest tip on the shoot as well as the distance from the point frame to the shoot five inches from the tip. This way, we could approximate the angle of the shoot relative to the ground. Using the same criteria as for the pin-drop measurements, we measured the distance from the top of the shoot to the soil. In addition, the row number and pin-hole number nearest to the shoot's location with respect to the point frame was also recorded . We then measured the leaf area index (LAI) of the shoot by holding an LAI-2000 (Li-Cor Inc., Lincoln, Nebraska, USA) in the exact location where the shoot had been and taking the average of three readings (one above, three below). For these measurements we used the one-quarter cut out and took care to always hold the instrument level and with the technician's body casting a uniform shadow over the instrument's eye, with the technician standing between the instrument and the sun. On occasion when it was raining during the shoot harvest, the area near where the shoot had been was marked with flagging tape, and the the LAI measurement was taken at a later date, using the height from frame/distance from ground meausrements as well as the row number and pin hole measurements as a guide. Once cut, the shoot was placed immediately into water and transported to the lab. Once in the lab, the end of each shoot was clipped under water to ensure that there were no air bubbles in the stem that would inhibit the flow of water. Shoots were then allowed to sit at ambient room conditions (~20-25 degrees Celsius) until the the photosynthetic rates could be measured. AREA CALCULATIONS: Area calculations were made using the open source software Image J, available at http://rsbweb.nih.gov/ij/download.html. The procedures for each kind of area calculation are outlined here: SHOOT SILHOUETTE AREA: Digital image capture of intact stem and leaves 1. Arrange the shoot on a white background (e.g. blank paper or foam board) as it sat in the LiCor conifer chamber. Add a note of sample number and date. 2. Place a ruler that you can later use as a reference. Ensure ruler/stem do not overlap. 3. Use a tripod to hold the camera in a steady position and as close as possible to the stem, keep this distance constant throughout the samples if possible to avoid the need to re-calibrate Image J. 4. Take a digital image of the shoot in very bright light conditions, using diffuser or reflector panels as needed to minimize shadows. [Shadows can be mistakenly analyzed in the software as plant tissue if not careful.] 5. Download the images in the computer, save them as TIFF files. SHOOT TISSUE AREA: Image capture of shoot tissues (leaf, petiole, stipule, organ, green/brown stem) using a scanner 1. Pluck the sample with forceps, arrange leaves, petioles, stipules, green and brown stems and inflorescences separately, grouped by type onto the white background of a plastic board. Place a ruler that you can later use as a reference. Add a note of sample number and date. 2. Press flat with the clear plastic cover. Ensure ruler/plant parts are not overlapping. 3. Place plastic side down on scanner (ensure no parts have overlapped when inverting plastic board). 4. Scan the images to the computer, save them as TIFF files. BOTH SILHOUETTE AND TISSUE AREA ANALYSES: In the Image J software program: 1. Open leaf image via Select File ? Open? your file name 2. Convert scanned colour image of leaf to greyscale: 3. Image?Type?8 bit 4. Set measurement scale: Draw a line over a 50 mm section of the ruler then Analyze ?Set Scale 5. In Set Scale window enter 50 into the 'Known Distance' box and change the 'Unit of Measurement' box to mm , check 'Global' (the Global option will apply the same scale to all the images you open after this, if you took the photos from different heights you might need to repeat this procedure every time) 6. Draw a new line and confirm that the measurement scale is correct. 7. Threshold the leaf image: Image? adjust? threshold 8. Play with sliders to include all of leaf in red and click ‘Apply’ 9. Calculate area of entire silhouette area and area of each tissue type: Enclose the region of the shoot or tissues that you wish to calculate the area for with the rectangular selection tool, then Analyze ? Analyze Particles 10. Select the options of display masks and display results. Area of measured pixels is displayed. Check that only your leaf is included in the outline (not the ruler or extraneous tissue types). The data of the leaf area is displayed on a new window ‘summary’, this data can be copied into Excel or the data can be saved directly as an Excel file. Keep summary window open between picture analyses to maintain a record of measured areas. 11. Save new black and white image as well as its original colour photo with an appropriate file name. DRYING AND WEIGHING: Once digital images of each shoot and tissue had been made, each plant tissue was separated, counted, and placed in a labeled coin envelope. These samples were then dried for a minimum of three days at 60 degrees Celsius prior to being weighed on a four-point balance with glass enclosure. Plant tissues were weighed in aggregate, thus the average mass included in these data are the total tissue mass divided by the count of that tissue (e.g. number of leaves, petioles, etc). In the same manner, plant tissure area was calculated in aggregate, thus the average area per leaf/petiole/stipule is based on the total area of that tissue divided by the count of that tissue. At the start of this project, we did not take care to distinguish leaves, petioles, or stipules. While not thought to make a significant difference in the area or mass calculations for most samples, we did not want to include the petioles in the CHN analyses. Thus, for those samples that had removeable petioles (all B. nana, most S. pulchra, but no Vaccinium spp. or L. palustre samples), the petioles were clipped after drying and the leaves re-weighed. In some cases the mass of the leaves with petioles removed was greater than the original mass; in these cases, the original mass was preserved. [The original mass of all samples weighed is listed in the ORIGINAL LEAF MASS W/ PETIOLE data-column.] NOTE: The area used for correcting the LiCor A/Ci and light curve data included leaves, petioles, and stipules. CHN ANALYSIS: Grinding: All leaf samples were dried in an oven at 60°C before grinding. Samples were small enough to grind the entire sample without subsampling. Leaves were ground using the Retsch MM 200 for 3 minutes or until a talcum powder consistency was achieved. Weighing: After grinding, samples were stored in glass scintillation vials and dried again at 60°C for at least 36 hours. Once samples were removed, vials were tightly re-capped. When not in use, vials were stored in dessicators. 3.5-4.5 mg of each sample was weighed into a 10x12 mm tin capsule. A standard calibration curve was created using increasing amounts of aspartic acid (from about 0.2 mg to 5.0 mg). A chemical standard, acetanilide, and an organic sample, apple leaf, were run after the standard curve. Every ten samples, an aspartic acid check standard and a duplicate of an already-packed sample were run. CN analysis: CN analysis was run between 10/4/2012 and 11/15/2012 by Rachel Rubin using the ThermoScientific 2000 at the Ecosystems Center, MBL, Woods Hole, MA. Duplicate sample values were averaged (mass, %N and %C) before inclusion into final results. The CHN data is available in the file "PF_CHN". pers-1 ITEX Manual, updated 2011 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 2012_GS_ITEX_PF_CHN_Data.csv Percent carbon and nitrogen of leaves from shoots harvested at three levels in the canopy from 19 plots dominated by S. pulchra and B. nana shrubs near LTER Shrub plots at Toolik Field Station, AK the summer of 2012. 2012_GS_ITEX_PF_CHN_Data.csv 1 \r\n column , " http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-arc.10147&urlTail=terrest/tracegas/data/2012_GS_ITEX_PF_CHN_Data.csv YEAR YEAR year of measurement yyyy DATE DATE date of measurement dd-mon-yy SITE SITE Toolik Toolik GROUP GROUP Measurement location in relation to Toolik Lake LTER Shrub plots; In vicinity of Block1 = Upland, IVO Block 2 = Outlet Measurement location in relation to Toolik Lake LTER Shrub plots; In vicinity of Block1 = Upland, IVO Block 2 = Outlet PLOT PLOT Individual plot identifier Individual plot identifier TREATMENT TREATMENT control or fertilized annually (with N and P) control or fertilized annually (with N and P) PLOT SIZE PLOT SIZE 1m x 1m point frame size 1m x 1m point frame size DOM VEG DOM VEG Dominant canopy vegetation Dominant canopy vegetation SPP SPP Shoot species sampled Shoot species sampled SHOOT ID SHOOT ID Identification for each shoot sampled (NOT unique); consists of canopy position (up/mid/low), species abbreviation, and a number Identification for each shoot sampled (NOT unique); consists of canopy position (up/mid/low), species abbreviation, and a number CANOPY POSN CANOPY POSN Relative position of shoot in the canopy Relative position of shoot in the canopy RUN RUN Number of the tray run through the CHN analysis (ThermoScientific2000) Number of the tray run through the CHN analysis (ThermoScientific2000) SAMPLE NAME SAMPLE NAME Unique sample ID created by combining the PLOT with the SHOOT ID Unique sample ID created by combining the PLOT with the SHOOT ID SAMPLE CODE SAMPLE CODE Sample location on the tray run through the CHN analysis (ThermoScientific 2000) number real MASS (MG) MASS (MG) Mass of the ground sample used for the run (mg leaf) milligram real %N %N percent Nitrogen in sample (%) percent real %C %C percent Carbon in sample (%) percent real C:N C:N Ratio of carbon to nitrogen (%C / %N) dimensionless real COMMENTS COMMENTS Notes about samples Notes about samples 116 2012_GS_ITEX_PF_CHN_Data.xlsx An excel file that has worksheets with the metadata and data. 2012_GS_ITEX_PF_CHN_Data.xlsx Microsoft Excel http://metacat.lternet.edu/das/dataAccessServlet?docid=knb-lter-arc.10147&urlTail=terrest/tracegas/xlsfiles/2012_GS_ITEX_PF_CHN_Data.xlsx Microsoft Excel file ratio of two quantities as percent composition (1:100)