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Pre-ABoVE: Vegetation and Physiographic Features of Pingos, North Slope, Alaska

Documentation Revision Date: 2017-06-29

Data Set Version: 1

Summary

This data set provides vegetation species and vegetation plot data collected in 1983 from 293 study plots on 41 pingos on the North Slope of Alaska. The pingos were located within the Arctic Coastal Plain in the Kuparuk, Prudhoe Bay, Kadleroshilik, and Toolik River areas. Specific attributes include dominant vegetation species, cover, soil pH, moisture, and physical characteristics of the plots.

The pingos are ice-cored, dome-shaped mounds found in permafrost regions and are an important component of the Alaskan central Arctic Coastal Plain landscape. A complete list of plant species was obtained for each plot. The vegetation pattern is complex due to differences in slope angle, slope aspect, effects of wind, disturbance by animals, site stability, and deposition of snow, as well as meso- and macroscale patterns related to the coastal climatic gradient and substrate variation.  

There are two data files with this data set in comma-separated (.csv) format.

Figure 1. A typical pingo, Prudhoe Bay, Alaska. This feature is 7 m high and has a basal diameter of 110 m (Walker, 1990).

Citation

Walker, M.D., and D.A. Walker. 2017. Pre-ABoVE: Vegetation and Physiographic Features of Pingos, North Slope, Alaska. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1507

Table of Contents

  1. Data Set Overview
  2. Data Characteristics
  3. Application and Derivation
  4. Quality Assessment
  5. Data Acquisition, Materials, and Methods
  6. Data Access
  7. References

Data Set Overview

Vegetation species and vegetation plot data were collected in 1983 from 293 study plots on 41 pingos within the Arctic Coastal Plain of the North Slope of Alaska. The pingos were located in the Kuparuk, Prudhoe Bay, Kadleroshilik and the Toolik River areas. Specific attributes include dominant vegetation, species, and cover, soil pH, moisture, and physical characteristics of the plots.

Pingos are ice-cored, dome-shaped mounds found in permafrost regions and are an important component of the Alaskan central Arctic Coastal Plain landscape. The pingo vegetation is a complex vegetation pattern which is the result of differences in in slope angle, slope aspect, effects of wind, disturbance by animals, site stability, and deposition of snow. In addition to these microscale controls, meso- and macroscale patterns related to the coastal climatic gradient and substrate variation are also reflected on pingos.

Sampling was opportunistic. Circular plots were 12.5 m2 and were permanently marked. Each pingo was assigned a name and number unless already named on US Geological Survey Maps.

Project: Arctic-Boreal Vulnerability Experiment (ABoVE)

The Arctic-Boreal Vulnerability Experiment (ABoVE) is a NASA Terrestrial Ecology Program field campaign based in Alaska and western Canada between 2016 and 2021. Climate change in the Arctic and Boreal region is unfolding faster than anywhere else on Earth. ABoVE seeks a better understanding of the vulnerability and resilience of ecosystems and society to this changing environment.

Acknowledgements:

These data were obtained from the Alaska Arctic Geoecological Atlas (http://agc.portal.gina.alaska.edu), which provides access to existing Arctic vegetation plot and map data in support of the ABoVE campaign.

Data Characteristics

Spatial Coverage:

ABoVE Grid Location: Ahh1Avv0.Bh2Bv2

Spatial Resolution: Point resolution

Temporal Coverage: Summer field seasons in 1983

Temporal Resolution: Each plot was sampled once

Study Area: (All latitude and longitude given in decimal degrees)

Site Westernmost Longitude Easternmost Longitude Northernmost Latitude Southernmost Latitude
Arctic Coastal Plain, North Slope, Alaska -149.949 -147.657 70.49962 69.71159

 

Data File Information

There are two data files with this data set in comma-separated (.csv) format.  

Table 1. Data files

Data File Name Description
pingos_environmental_data.csv Comprehensive set of environmental characterization data for pingo research plots including the descriptive site factors
pingos_species_data.csv The estimated percent land cover by species per plot
Companion files Description
pingos_veg_plots_report.pdf Document which provides details of the research in.pdf format
scalar_value_tables_pingos_env_data.pdf Document which provides the tables of scalar values and codes used to estimate and describe environmental variables. This pdf is provided for user’s convenience. These tables were taken from the companion file above.
Pingo_Veg_Plots.pdf A pdf of this guide document

 

Table 2.  Variables in the file pingos_environmental_data.csv

Much of the data were described and estimated using scalar values and codes. Refer to the companion file scalar_value_tables_pingos_env_data.pdf  for these values and codes.

Data not provided are represented as -9999.

Column number Variable Units/format Description
1 date yyyy Year plots were investigated
2 pingo_number numeric Pingo number as provided by the author
3 plot_number numeric Plot number
4 author_plot number numeric Pingo number and plot number at that pingo, listed as #_#
5 study_area   Areas where plots and pingos were located: Prudhoe Bay, Toolik River, Kadleroshilik, or Kuparuk
6 pingo_name   Name assigned to pingo unless already assigned by the US Geological Survey (USGS)
7 latitude decimal degrees Plot latitude provided in decimal degrees.
8 longitude decimal degrees Plot longitude provided in decimal degrees.
9 plant_community   Plant community name
10 general_landscape_unit code Code (number) used to describe the general landscape.
11 slope_angle degrees Slope angle of the plot in degrees
12 aspect degrees Aspect in degrees
13 slope_position code Plot-slope position 
14 exposure_wind scalar Exposure of individual plots to winds estimated using a scalar value.
15 thaw_depth cm Thaw depth in cm
16 snow_duration scalar Snow cover and duration estimated using the ordinal scale of 1-10
17 surface_stability scalar Surface stability estimated using the ordinal scale of 1-10
18 cryoturbation % Cryoturbation (0-100%) estimated using the ordinal scale of 1-10, with 0% being 1, and 75-100% being 10
19 microrelief_ht cm Microrelief height
20 pH   Soil pH
21 soil_type code Code (number) used to describe the soil:1-13
22 soil_or_site_moisture scalar Estimated soil or site moisture. Note that there is uncertainty as to whether this is soil or site moisture according to the data provider. Refer to Tables 9 and 13 in the companion file for the scalar values
23 plot_size m2 Plot size: 12.5 m2
24 microsite   Describes releve location
25 soil_texture   Soil texture as described in notes

  

Table 3. Variables in the file pingos_species_data.csv

This file provides species cover classes by percent.

Column number Column header Description
1 PASL_taxon_scientific_name Current nomenclature according to the Panarctic Species List (PASL)
2 PASL_taxon_scientific_name_author Current nomenclature according to the Panarctic Species List (PASL) with the data authors name
3 dataset_taxon Data set taxonomy
4-296 TURBOVEG_plot_accession_number and dataset_plot_number_author Two rows of 293 column headers.  The first row is TURBOVEG accession numbers. Column headers= 10632-10924. The 2nd row are the plot numbers as named in the original data set by pingo number_plot number; column headers= numbers 1_1 to 41_16 (nonsequential #s).  The data are species cover classes by percent*
 

* Data file notes:

Values greater than 0.5 but less than 1 percent were assigned the value 0.7. 

Values less than 0.5 but greater than 0 percent were assigned the value 0.3 percent.

In two instances, taxa were lumped into a single taxon in the PASL:

 1) Cetraria islandica (Cetraria islandica and Cetraria islandica crispiformis)

 2) Cladonia fimbriata (Cladonia fimbriata and Cladonia chlorophea).

 

Table 4. Example data from the file pingos_species_data.csv

    TURBOVEG_plot_accession_number 10632 10633 10634
    dataset_plot_number_author 1_1 1_2 1_3
PASL_taxon_scientific_name PASL_taxon_scientific_name_author dataset_taxon      
Abietinella abietina Abietinella abietina (Hedw.) Fleisch. Thuidium abietinum 0 0 0
Achillea millefolium subsp. borealis Achillea millefolium subsp. borealis (Bong.) Breitung Achillea borealis 0 0 0
Alectoria ochroleuca Alectoria ochroleuca (Hoffm.) Massal. Alectoria ochroleuca 0 0 0

 

Application and Derivation

These data could be useful to climate change studies.

Quality Assessment

Data were entered into the CYBER computer at the University of Colorado for analysis. At each stage, a series of checks was used to ensure accuracy against the field notes. Refer to the comp file pingos_veg_plots_report.pdf for additional information.

Data Acquisition, Materials, and Methods

Site characteristics

The study area was within the Arctic Coastal Plain of the North Slope of Alaska, in the Kuparuk, Prudhoe Bay, Kadleroshilik, and Toolik River areas.  Pingos are ice-cored, dome-shaped mounds found in permafrost regions and are an important component of the Alaskan central Arctic Coastal Plain landscape. They may be as high as 50-m, with basal diameters exceeding 1-km, but on the coastal plain most are between 5 and 20-m high, with diameters between 70 and 400-m. Pingos are not evenly distributed across the coastal plain but are abundant in areas with sand and gravel substrates.

The pingo vegetation is primarily dominated by Dryas integrifolia although it is not present in all stand types. The complexity of the vegetation pattern is a result of differences in in slope angle, slope aspect, effects of wind, disturbance by animals, site stability, and deposition of snow. In addition to these microscale controls, meso- and macroscale patterns related to the coastal climatic gradient and substrate variation are also reflected on pingos.

Soils on the pingos are Mollisol, Inceptisol, Entisol, and Histosols. Distribution of the soil types was related to microsite and regional gradients (Walker, 1990).

The pingos in the study are described as (1) steep-sided, with relatively steep side slopes, usually between 10 and 30-m, found exclusively within the boundaries of recognizable drained thaw- lake basins, and presumed to be a result of the formation of permafrost in thawed, saturated, coarse sediments following lake drainage; or (2) broad-based, having a greater total volume and gentler side slopes than the steep-sided pingos (Walker et al., 1991). Nine pingos in the study area were considered to be the broad-based type.

Methods

A total of 293 plots were located on 41 pingos in the four areas listed above.  Final latitude and longitude for the pingos were estimated in 2014 using topographic maps and a project mylar overlay, color infrared aerial photographs, and Google Earth.

pingo locations

Figure 2. Locations of  the 41 pingos in the study areas of the Arctic Coastal Plain (Walker, 1990).

Sampling was opportunistic. Circular plots were 12.5-m2 and were permanently marked. Each pingo was assigned a name and number unless already named on USGS Maps.

Plots were located in up to nine different locations on the pingos including:

 a) bottom of snowbank (40 plots)

 b) middle snowbank (45 plots)

 c) ENE side of the pingo (36 plots)

 d) north slope of pingo (41 plots)

 e) south slope of pingo (45 plots)

 f) summit of pingo (41 plots)

 g) WSW slope of pingo (39 plots)

 h) very late lying or permanent snowbed (4 plots)

 i) frost boil (1 plot).

One plot had insufficient location information.

Pingo diagram

Figure 3. Topographic map of Pingo 6 (Angel) with a 1.5-m contour interval. Seven microsite sampling locations are labeled as (1) ENE wind exposed, (2) summit, (3) dry leeward side snowbank, (4) middle of snowbank on leeward side (well-drained), (5) bottom of snowbank at leeward base of pingo (poorly drained), (6) south slope, (7) north slope. Topographic information from Air Photo Tech 1979 (Walker, 1990).

The plots occurred in seven broad habitat types:

 a) zoogenic communities associated with animal dens and bird mounds (50 plots)

 b) willow shrub vegetation of riparian areas and warm habitats (8 plots)

 c) talus slope, debris and alluvial vegetation (4 plots)

 d) deep snowbed vegetation (40 plots)

 e) dry to moist dwarf-shrub heath and low-shrub vegetation on acidic nutrient poor substrates (40 plots)

 f) dry and mesic dwarf-shrub and graminoid vegetation on non-acidic substrate (133 plots)

 g) steppe tundra communities on south facing slopes of pingos (19 plots).

 A complete list of plant species was obtained for each plot.

 

Environmental Plot Data

Most of the environmental plot data were estimated using scalar values and prior information from related publications. Soil pH was determined in the laboratory.

Refer to the companion file pingos_veg_plots_report.pdf for additional information.

 

This data set was provided by the GINA repository at http://geobotanical.portal.gina.alaska.edu/plot-archive/plot-datasets/33-toolik-lake.

 

Data Access

These data are available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Pre-ABoVE: Vegetation and Physiographic Features of Pingos, North Slope, Alaska

Contact for Data Center Access Information:

References

Walker, M.D., D.A. Walker, K.R. Everett, and S.K. Short. 1991. Steppe Vegetation on South-Facing Slopes of Pingos, Central Arctic Coastal Plain, Alaska, U.S.A. Arctic and Alpine Research 23: 170-188.

Walker, M.D. 1990. Vegetation and floristics of pingos, Central Arctic Coastal Plain, Alaska. Dissertationes Botanicae. J. Cramer, Stuttgart, Germany.