Late season thaw depth measured in the Arctic Long Term Ecological Research (ARC LTER) moist acidic tussock experimental plots at Toolik Field station, Alaska Arctic 1993 to 2018

Abstract: 

Late season thaw depth was measured in the Arctic Long Term Ecological Research (ARC LTER) experimental plots (1981 Moist Acidic Tussock, 1989 Moist Acidic Tussock, 2006 Low Fertilization Moist Acidic Tussock, 1989 Moist Non-acidic Tussock, 1989 Moist Non-acidic Non-tussock and 1989 Wet Sedge tundra) at Toolik Lake, Alaska using a steel thaw probe. Note: for 2017-2018 only 1989 Moist Non-Acidic Tussock Tundra and 2006 Low fertilization Moist Acidic Tussock Tundra were measured. For other sites it has become difficult to distinguish rocks from frozen soil with a steel thaw probe.

Project Keywords: 

Data set ID: 

1610

EML revision ID: 

9
Published on EDI/LTER Data Portal

Citation: 

Shaver, G., Rastetter, E. 2019. Late season thaw depth measured in the Arctic Long Term Ecological Research (ARC LTER) moist acidic tussock experimental plots at Toolik Field station, Alaska Arctic 1993 to 2018 Environmental Data Initiative. http://dx.doi.org/10.6073/pasta/e84452e07fe88c29e1ca4606adcd2702
People

Owner/Creator: 

Contact: 

Additional People: 

Associated Researcher
Dates

Date Range: 

Friday, August 20, 1993 to Monday, August 20, 2018

Publication Date: 

2019

Methods: 

Plots are setup as indicated below, with annual fertilization treatments of 10 g/m2 Nitrogen (as NH4NO3) and 5 g/m2 Phosphorous (as triple superphosphate) for all N, P and NP treatments. Greenhouses and shade houses are set up annually in early June and removed in mid-August.

Sites:

1981 Moist Acidic Tussock

Plots were setup in June 1981 with annual fertilization treatments of 10 g/m2 Nitrogen (as NH4NO3) and 5 g/m2 Phosphorous (as triple superphosphate) were applied. Greenhouses and shade houses were annually set up in late May or early June and removed in the end of August or early September. Greenhouses and shade houses were discontinued in 1989. There are 4 replicate blocks, each containing 1 replicate of each of the following treatments.
 Control (CT)
 Fertilized (NP)
 Greenhouse (GH)
 Greenhouse fertilized (GHNP)
 Shade (SH)

1989 Moist Acidic Tussock Tundra
      Blocks 1-4
                   (CT, N, P, NP, GH, GHNP, Shade, and Shade NP treatments)
                    Treatments began summer of 1989. Plots size are 5x20 meters
                         plot/treatment except for GH, GHNP, Shade, and Shade NP which are 2.4 x 4.9 meters.
                  
                 Exclosures of large mesh and small mesh fences:
                  (EXCT fence, EXCT no fence, EXNP fence and EXNP no fence)
                    Treatments began in 1997. Plot size are 5x10 meters.
                   All fences are large mesh with an inner 5x5 meter small mesh fence.
    
Moist Non-Acidic Non-Tussock Tundra
      Blocks 1-3 (CT, N, P and NP treatments)
                    Treatments began summer of 1997. Plots size are 5x20 meters
                         plot/treatment.
   

Moist Non-Acidic Tussock Tundra
      Blocks 1-3 (CT, N, P and NP treatments) (GH and GHNP treatments are on block 1 and 2 only)
                    Treatments began summer of 1997. Plots size are  5x20 meters
Wet Sedge
        Block 1 - Toolik Inlet (CT, N, P, NP, GH, GHNP, and Shade treatments)
                     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

Low Fertilization - in 2006, a new set of experimental treatments were established in MAT near the earlier plots described above. These include a gradient of fertilization treatments that receive nitrate or ammonium alone, or receive N and P additions with 0.5, 1, 2, 5, or 10 g N added with half of that amount added as P. An additional set of plots were set aside upon establishment for future experiments, and are noted as H.

 A total of 8 measurements were made with a stainless steel probe. All measurement made in inter-tussock mossy area; not wet hollows. Depths for each plot were taken along the 20 meter sides every at 2.5, 7.5, 12.5, 17.5 meters. For greenhouses and shade houses one depth was taken between every set of rafters (every 1.2 meters).

No measurements were made in the shrub or heath experimental plots due to gravel and rocks.

NOTES AND COMMENTS:  The tussock greenhouses and shade houses were measured after the plastic and shade cloth were removed.

2006 Measurements were not made in Non- Acidic sites because thaw was deep enough that a rock layer was reached. 
2008 No measurements in Non acidic tundra.
2009 Thaw in the low fertilization plots were made.

2016 Seasonal measurements but only 5 reps were done. 

2017-2018 only 1989 Moist Non-Acidic Tussock Tundra and 2006 Low fert Moist Non-Acidic Tussock Tundra were measured.  For other sites it has become difficult to distinguish rocks from frozen soil with a steel thaw probe. 

Version Changes: 

There is gap between 1993 and 1997 when thaw was not measured.
Updated Metadata sheet
Version 1 Created new metadata excel sheet. 5apr05 Jim L
Version 2: Added LTERNET Data Access server proxy for Excel and comma delimited data files.
Version 3: Update LTERNET Data Access server proxy link for Excel and comma delimited data files. Changed from knb to das in url.
Version 4: Added data from 2006 - 2009. Date updated to ISO standard Jim L Mar 2010
Version 5: Changed cell L470 from "3/28" to "28". Updated metadata form to newer version (without site sheet). Updated data to 2012. CH 2 Feb 2013. Updated to newer metadata with site sheet. CH March 2013.
Version 6: Checked keywords against the LTER network preferred list and replaced non-preferred terms. Jim L 27Jan14
Version 7: Changed Distribution URL since the LTER network DAS system is being discontinued. Jim L 9Apr2015
updated file to 2015.
Added 2016 data Jim Laundre 23Feb2017
Version 8: Added 2017-2018 data Jim L
Version 9: Corrected spelling in title and abstract and defined acronyms. Jim L June 2019

Sites sampled.

Download a comma delimited (csv) or Excel file (includes metadata and data sheets).

Use of the data requires acceptance of the data use policy --> Arctic LTER Data Use Policy

To cite this data set see the citation example on the LTER Network Data Portal page for this data set.