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Pre-ABoVE: Arctic Vegetation Plots at Toolik Lake, Alaska, 1989

Documentation Revision Date: 2016-09-27

Data Set Version: V1

Summary

This data set provides environmental, soil, and vegetation data collected in August 1989 from 81 study plots at the Toolik Lake research site, located in the southern Arctic Foothills of the Brooks Range, Alaska. Data includes the baseline plot information for vegetation, soils, and site factors for the study plots subjectively located in 26 communities and 4 broad habitat types across the glaciated landscape. Specific attributes include: dominant vegetation species, cover, indices, and biomass pools; soil chemistry, physical characteristics, moisture, and organic matter. This product brings together for easy reference all the available information collected from the plots that has been used for the classification, mapping, and analysis of geobotanical factors in the Toolik Lake region and across Alaska.

The data set includes 4 data files in *.csv format and one additional companion file.

Figure 1: Toolik Lake Permanent Vegetation Plot SWT-16.

Citation

Walker, D.A. 2016. Pre-ABoVE: Arctic Vegetation Plots at Toolik Lake, Alaska, 1989. ORNL DAAC, Oak Ridge, Tennessee, USA. http://dx.doi.org/10.3334/ORNLDAAC/1333

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

This data set provides environmental, soil, and vegetation data collected in August 1989 from 81 study plots at the Toolik Lake research site, located in the southern Arctic Foothills of the Brooks Range, Alaska. Data includes the baseline plot information for vegetation, soils, and site factors for the study plots subjectively located in 26 communities and 4 broad habitat types across the glaciated landscape. Specific attributes include: dominant vegetation species, cover, indices, and biomass pools; soil chemistry, physical characteristics, moisture, and organic matter. This product brings together for easy reference all the available information collected from the plots that has been used for the classification, mapping, and analysis of geobotanical factors in the Toolik Lake region and across Alaska.

The Pre-ABoVE vegetation plot datasets were curated to create the Alaska Arctic Vegetation Archive (AVA-AK; Walker et al. 2016b, Walker 2013)  The AVA-AK is a regional database that is part of the larger Arctic Vegetation Archive (Walker 2016a, Walker et al. 2013, Walker and Raynolds 2011).  The database contains vegetation plots from homogeneous plant communities with tables of cover or cover-abundance scores for all species, and accompanying environmental site data.  Field data were collected using Braun-Blanquet, US National Vegetation Classification protocols, or comparable methods.

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: Area surrounding Toolik Lake, Alaska

ABoVE Grid Location: Ah1v0.Bh2v3

Spatial Resolution: Point samples

Temporal Coverage: 19890801 to 19890824

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

Toolik Lake, Alaska

 -149.6506

 -149.5873  68.6430  68.6228

 

Data File Information

The data set includes four data files in *.csv format -- Toolik_Lake_Soil_Data, Toolik_Lake_Species_Data, Toolik_Lake_Spectral_Biomass_Data, and Toolik_Lake_Environmental_Data.

There is one companion file --  Toolik_Lake_Veg_Plots_Report_WalkerBarry1991.pdf

Table 1. Data and companion files

Data File Name

Description

Toolik_Lake_Soil_Data.csv

Soil characterization data for Toolik Lake research plots

Toolik_Lake_Species_Data.csv

Species cover data for Toolik Lake research plots

Toolik_Lake_Spectral_Biomass_Data.csv

NDVI, LAI, iPAR and above ground biomass data for Toolik Lake research plots

Toolik_Lake_Environmental_Data.csv

Comprehensive set of environmental characterization data for Toolik Lake research plots including the descriptive site factors. Most measurement data have been processed to provide values at a common 10 cm depth. This measurement comparability facilitates analysis of geobotanical relationships across Alaska.

 

 

Companion File Name

Description

Toolik_Lake_Veg_Plots_Report_WalkerBarry1991.pdf

Summary report of all the data collected, methods of collection, maps/plots etc. for the 81 study plots at the Toolik Lake research site. Walker and Barry (1991).

 

Data Descriptions: The column names, their units and descriptions for each of the *.csv data files are listed below.

Table 2. Toolik_Lake_Soil_Data.csv

Column Name Units  Description
SAMPLE_NO   Soil Sample number
PLOT_NO   Plot number where the soil sample was collected
HORIZON    Soil horizon
DEPTH  CM Depth of the soil layer
WET_COLOR  MUNSELL Color of wet soil in the soil sample following Munsell System of Color Notation
BULK_DENSITY  G/CC Bulk density of the soil sample
GRAVEL_GREATER_THAN_2MM  % Percentage of gravel that were greater than 2 mm in size in the soil sample
SAND  % Percentage of sand in the soil sample
SILT  % Percentage of silt in the soil sample
CLAY  % Percentage of clay in the soil sample
TEXTURE    Texture of the soil in the soil sample
WATER_GRAVIMETRIC  % Gravimetric water content in the soil sample
WATER_FIELD_CAPACITY_0_33_ATM  % Percentage of moisture content in the soil sample at 15 atmospheres of pressure
WATER_WILTING_POINT_15_ATM  % Percentage of moisture content in the soil sample at 1/3 atmosphere of pressure
ORGANIC_MATTER  % Percentage of organic matter in the soil sample
PH_PASTE   PH of the soil sample
ELECTRICAL_ CONDUCTIVITY_PASTE  MMHOS/CM Electrical conductivity of the soil sample
NO3_NH4HCO3_DTPA_EXTRACT  ppm Extractable NO3-NH4HCO3 in the soil sample
P_NH4HCO3_DTPA_EXTRACT  ppm Extractable P in the soil sample
K_NH4HCO3_DTPA_EXTRACT  ppm Extractable K in the soil sample
ZN_NH4HCO3_DTPA_EXTRACT  ppm Extractable Zn in the soil sample
FE_NH4HCO3_DTPA_EXTRACT  ppm Extractable Fe in the soil sample
MN_NH4HCO3_DTPA_EXTRACT  ppm Extractable Mn in the soil sample
CU_NH4HCO3_DTPA_EXTRACT  ppm Extractable Cu in the soil sample
CA_NH4OAC_EXTRACT  MEQ/100 G Extractable Ca in the soil sample
MG_NH4OAC_EXTRACT  MEQ/100 G Extractable Mg in the soil sample
NA_NH4OAC_EXTRACT  MEQ/100 G Extractable Na in the soil sample
K_NH4OAC_EXTRACT  MEQ/100 G Extractable K in the soil sample
CACO3_EQUIVALENT  % CACO3 equivalent in the soil sample
CATION_EXCHANGE_CAPACITY  MEQ/100 G Cation exchange capacity of the soil sample
P_BRAY_METHOD ppm Available P in the soil as detected by Bray method

 

Table 3. Toolik_Lake_Spectral_Biomass_Data.csv

Column Name Units  Description
SITE   Toolik Lake
PLOT_NUMBER   Plot Number
MICROSITE   Microsite description of the plots
PLOT_ID   Combination of plot number and microsite
PHYSIOGRAPHIC_CATEGORY   Physiographic category
ACIDIC_NONACIDIC   Description of acidic/non-acidic
ALLIANCE   Vegetation alliance
ASSOCIATION_NAME   Vegetation association name
SUBASSOCIATION   Vegetation subassociation
RED_BAND  % Red/visible band
NIR_BAND  % Near-infrared
SAVI   Soil Adjusted Vegetation Index
NDVI   Normalized Difference Vegetation Index
2ND_DERIV_AT_695NM   2nd Derivative at 695NM
2ND_DERIV_AT_743NM   2nd Derivative at 743 NM
TRANSMITTED  % Percentage of transmitted radiation
IPAR  % Percentage of incidental photosynthetically active radiation
0_58K_LAI   0.58K Leaf Area Index
0_65K_LAI   0.65K Leaf Area Index
0_61K_LAI   0.61K Leaf Area Index
MEAN_LAI   Average Leaf Area Index
PLOT_AVERAGE_LAI   Average Leaf Area Index for the plot
PLOT_AVERAGE_NDVI   Average  Normalized Difference Vegetation Index for the plot
LIVE_GRAMINOID  G/SQUARE METER Amount of live graminoid
DEAD_GRAMINOID  G/SQUARE METER Amount of dead graminoid
LIVE_FORB  G/SQUARE METER Amount of live forb
DEAD_FORB  G/SQUARE METER Amount of dead forb
LIVE_DECIDUOUS_SHRUB  G/SQUARE METER Amount of live deciduous shrub
DEAD_DECIDUOUS_SHRUB  G/SQUARE METER Amount of dead deciduous shrub
WOODY_DECIDUOUS_SHRUB  G/SQUARE METER Amount of woody deciduous shrub
LIVE_EVERGREEN_SHRUB  G/SQUARE METER Amount of live evergreen shrub
DEAD_EVERGREEN_SHRUB  G/SQUARE METER Amount of dead evergreen shrub
WOODY_EVERGREEN_SHRUB  G/SQUARE METER Amount of woody evergreen shrub
SPHAGNUM  G/SQUARE METER Amount of sphagnum
OTHER_MOSS  G/SQUARE METER Amount of other types of moss
LICHENS  G/SQUARE METER Amount of lichens
MISCELLANEOUS_DEAD  G/SQUARE METER Other vegetation types that are dead
ALGAE  G/SQUARE METER Amount of algae
LIVE_EQUISETUM  G/SQUARE METER Amount of live equisetum
DEAD_EQUISETUM  G/SQUARE METER Amount of dead equisetum
AQUATIC_MOSS  G/SQUARE METER Amount of aquatic moss
TOTAL_BIOMASS  G/SQUARE METER Amount of total biomass
GREEN_BIOMASS_INCLUDING_LICHENS  G/SQUARE METER Amount of green biomass including lichens
GREEN_BIOMASS_WITHOUT_LICHENS  G/SQUARE METER Amount of green biomass excluding lichens

 

Table 4. Toolik_Lake_Environmental_Data.csv

Column Name

Units 

Description

FIELD_PLOT_NUMBER

 

Field plot number

PRINCIPAL_HABITAT

 

Principal habitat in the plot

PRELIMINARY_COMMUNITY_NAME

 

Preliminary vegetation type within the plots based on habitat and dominant species

PLANT_COMMUNITY

 

Primary vegetation types

MICROSITE

 

Detailed description of microsite within the plots

DATE_SAMPLED 

YYYYMMDD

Sampling date

LATITUDE

DD

Latitude of the center of the plots

LONGITUDE

DD

Longitude of the center of the plots

LANDFORM

 

Landform of the plots

LANDFORM_DESC

 

Description of landforms of the plots

SURFICIAL_GEOLOGY

 

Surficial geology of the plots

SURFICIAL_GEOLOGY_DESC

 

Description of surficial geology of the plots

GLACIAL_GEOLOGY

 

Glacial geology of the plots

GLACIAL_GEOLOGY_DESC

 

Description of glacial geology of the plots

SURFICIAL_GEOMORPHOLOGY

 

Surficial geomorphology of the plots

SURFICIAL_GEOMORPHOLOGY_DESC

 

Description of surficial geomorphology of the plots

MICROSITE

 

Microsite of the plots

MICROSITE_DESC

 

Description of microsite of the plots

TOPOGRAPHIC_POSITION

 

Topographic position of the plots

TOPOGRAPHIC_POSITION_DESC

 

Description of the topographic position of the plots

SLOPE

Degrees

Slope of the plots

ASPECT

Degrees

Aspect of the plots

EXPOSURE

 

Exposure of the plots

EXPOSURE_DESC

 

Description of the exposure of the plots

SITE_MOISTURE

 

Site moisture of the plots

SITE_MOISTURE_DESC

 

Description of the site moisture of the plots

ESTIMATED_SNOW_DURATION

 

Estimated snow duration within the plots

ESTIMATED_SNOW_DURATION_DESC

 

Description of estimated snow duration within the plots

STABILITY

 

Stability of the plots

STABILITY_DESC

 

Description of stability of the plots

CRYOTURBATION

 

Cryoturbation within the plots

MICRORELIEF_HEIGHT

CM

Microrelief height of the plots

THAW_DEPTH 

CM

Depth to permafrost of the plots

WATER_COVER 

%

Percentage of water cover in the plot

BARE_SOIL_COVER

%

Percentage of bare soil cover in the plot

ROCK_COVER

%

Percentage of rock cover in the plot

SOIL_UNITS

 

Soil units in the plot

SOIL_UNITS_DESC

 

Description of the soil units within the plot

SOIL_MOISTURE

 

Soil moisture content within the plots

SOIL_MOISTURE_DESC

 

Description of the soil moisture content within the plots

TALL_SHRUB_COVER

%

Percentage of tall shrub cover in the plot

LOW_SHRUB_COVER

%

Percentage of low shrub cover in the plot

DWARF_SHRUB_COVER

%

Percentage of dwarf shrub cover in the plot

MEAN_SHRUB_HEIGHT

CM

Average shrub height within the plot in the plot

GRAMINOID_COVER

%

Percentage of graminoid cover in the plot

FORB_COVER

%

Percentage of forb cover in the plot

LICHEN_COVER

%

Percentage of lichen cover in the plot

BRYOPHYTE_COVER

%

Percentage of bryophyte cover in the plot

HORSETAIL_COVER

%

Percentage of horsetail cover in the plot

DISTURBANCE_HUMAN

 

Disturbance by humans

DISTURBANCE_HUMAN_DESC

 

Description of disturbance by humans

DISTURBANCE_FOX

 

Disturbance by fox

DISTURBANCE_FOX_DESC

 

Description of disturbance by fox

DISTURBANCE_BEAR

 

Disturbance by bear

DISTURBANCE_BEAR_DESC

 

Description of disturbance by bear

DISTURBANCE_CARIBOU

 

Disturbance by caribou

DISTURBANCE_CARIBOU_DESC

 

Description of disturbance by caribou

DISTURBANCE_SQUIRREL

 

Disturbance by squirrel

DISTURBANCE_SQUIRREL_DESC

 

Description of disturbance by squirrel

DISTURBANCE_LEMMING_VOLE

 

Disturbance by lemming vole

DISTURBANCE_LEMMING_VOLE_DESC

 

Description of disturbance by lemming vole

DISTURBANCE_MOOSE

 

Disturbance by moose

DISTURBANCE_MOOSE_DESC

 

Description of disturbance by moose

DISTURBANCE_BIRD

 

Disturbance by birds

DISTURBANCE_BIRD_DESC

 

Description of disturbance by birds

DISTURBANCE_INSECT

 

Disturbance by insect

DISTURBANCE_INSECT_DESC

 

Description of disturbance by insect

HORIZON_AT_10_CM

 

Soil horizon at 10 cm depth

HORIZON_DEPTHS

CM

Depth of the soil horizon

WET_COLOR_AT_10_CM 

MUNSELL

Color of wet soil at 10 cm depth following Munsell System of Color Notation

BULK_DENSITY_AT_10_CM

gm/cm^3

Bulk density of the soil at 10 cm depth

GRAVEL_GT_THAN_2MM_AT_10_CM 

%

Percentage of gravel that were greater than 2 mm in size in the soil at 10 cm depth

SAND_AT_10_CM 

%

Percentage of sand in the soil at 10 cm depth

SILT_AT_10_CM 

%

Percentage of silt in the soil at 10 cm depth

CLAY_AT_10_CM 

%

Percentage of clay in the soil at 10 cm depth

TEXTURE_AT_10_CM 

 

Texture of the soil at 10 cm depth

SOIL_TEXTURE_TOP_MINERAL_HORIZON

 

Soil texture at the top of the mineral horizon

WATER_GRAVIMETRIC_AT_10_CM 

%

Gravimetric water content in the soil at 10 cm depth

WATER_FIELD_CAPACITY_0_33_ATM_AT_10_CM 

%

Percentage of moisture content in the soil at 10 cm depth at 15 atmospheres of pressure

WATER_WILTING_POINT_15_ATM_AT_10_CM 

%

Percentage of moisture content in the soil at 10 cm depth at 1/3 atmosphere of pressure

ORGANIC_MATTER_AT_10_CM 

%

Percentage of organic matter in the soil at 10 cm depth

PH_PASTE_AT_10_CM

 

PH of the soil at 10 cm depth

SOIL_PH_TOP_OF_MINERAL_HORIZON

 

PH of the soil at the top of the mineral horizon

ELECTRICAL_CONDUCTIVITY_PASTE_AT_10_CM

MMHOS/CM

Electrical conductivity of the soil at 10 cm depth

NO3_NH4HCO3_DTPA_EXTRACT_AT_10_CM 

PPM

Extractable NO3-NH4HCO3 in the soil at 10 cm depth

P_NH4HCO3_DTPA_EXTRACT_AT_10_CM 

PPM

Extractable P in the soil at 10 cm depth

K_NH4HCO3_DTPA_EXTRACT_AT_10_CM 

PPM

Extractable K in the soil at 10 cm depth

ZN_NH4HCO3_DTPA_EXTRACT_AT_10_CM 

PPM

Extractable Zn in the soil at 10 cm depth

FE_NH4HCO3_DTPA_EXTRACT_AT_10_CM 

PPM

Extractable Fe in the soil at 10 cm depth

MN_NH4HCO3_DTPA_EXTRACT_AT_10_CM 

PPM

Extractable Mn in the soil at 10 cm depth

CU_NH4HCO3_DTPA_EXTRACT_AT_10_CM 

PPM

Extractable Cu in the soil at 10 cm depth

CA_NH4OAC_EXTRACT_AT_10_CM

MEQ/100 G

Extractable Ca in the soil at 10 cm depth

MG_NH4OAC_EXTRACT_AT_10_CM 

MEQ/100 G

Extractable Mg in the soil at 10 cm depth

NA_NH4OAC_EXTRACT_AT_10_CM 

MEQ/100 G

Extractable Na in the soil at 10 cm depth

K_NH4OAC_EXTRACT_AT_10_CM

MEQ/100 G

Extractable K in the soil at 10 cm depth

CACO3_EQUIVALENT_AT_10_CM

%

CACO3 equivalent in the soil at 10 cm depth

CATION_EXCHANGE_CAPACITY_AT_10_CM 

MEQ/100 G

Cation exchange capacity of the soil at 10 cm depth

P_BRAY_METHOD_AT_10_CM 

PPM

Available P in the soil at 10 cm depth as detected by Bray method

ELEVATION

M

Elevation of the plot

PLOT_SIZE 

M^2

Size of the plot

PLOT_SHAPE

 

Shape of the plot

SOIL_ORGANIC_DEPTH 

CM

Depth of soil organic layer

 

Table 5. Toolik_Lake_Species_Data.csv

Column Numbers Column Name Units  Description
1 PASL_TAXON_SCIENTIFIC_NAME_NO_AUTHORS   Current Taxonomy according to the Panarctic Species List (PASL) includng authors names
2 PASL_TAXON_SCIENTIFIC_NAME_WITH_AUTHOR(S)   Current Taxonomy according to the Panarctic Species List (PASL)
3 DATASET_TAXON   Dataset taxonomy
4 to 84 SWT1 to SWT81   Column headings are all 81 plot numbers. The data values are Species Cover Classes (Braun-Blanquet cover-abundance scale): where r (rare), + (common, but less than 1 percent cover), 1 (1-5 percent), 2 (6 to 25 percent), 3 (25 to 50 percent), 4 (51 to 75 percent), 5 (76 to 100 percent).

 

Application and Derivation

These data bring together for easy reference all the available information collected from the plots and have has been used for the classification, mapping and analysis of the geobotanical factors in the Toolik Lake region (Hobbie and Kling, 2014; Shippert et al., 1995; Walker et al, 1994; Walker et al., 1995 ). Derived regional maps of these data will be used in regional models of fluxes of trace gases, water, and energy from tundra surfaces. In addition, a circumpolar vegetation classification resulting from these data sets would be highly desirable to extend the results to the entire arctic region.

Quality Assessment

No specific quality assessment information provided.

Data Acquisition, Materials, and Methods

The eighty-one study plots at the Toolik Lake research site located in the southern Arctic Foothills of the Brooks Range, Alaska (shown in Figure 2) were subjectively located in 26 plant communities and 4 broad habitat types including: dry tundra (19 plots), snowbeds (7 plots), moist tundra (27 plots), and wet tundra (15 plots).

 

Location map of the 81 Toolik Lake Permanent Vegetation Plots

Figure 2. Location map of the 81 Toolik Lake Permanent Vegetation Plots.

 

Vegetation Plot Sampling

A formal relevé sampling of the designated plots was done during the period 1-24 August,1989 to sample the diversity of vegetation types of the region. For more details see Toolik_Lake_Veg_Plots_Report_WalkerBarry1991.pdf.

Sampling of the plots included:

  1. Taking photographs of the general site (Figure 1), vegetation (Figure 3), and soil profiles (Figure 4). Photos are provided in Walker and Barry (1991).
  2. Measuring site factors listed in listed in Table 4 plus measurements of thaw depth, estimates of cover of bare soil, rocks, and the major plant growth forms as summarized in Table 4.
  3. Field sampling of soils where soil pits were dug adjacent to the plots and described and classified according to the U.S. soil taxonomy [Walker and Barry, 1991]. Soil variables for each plot, typically at 10 cm depth was derived from the complete soils data in Table 2. Soil texture is primarily from the top mineral horizon per the soil text descriptions; secondarily from 10 cm, or listed as ‘organic’ when no mineral horizon is present.
  4. Laboratory analysis of soil samples
  5. Estimating vegetation cover using the Braun-Blanquet cover-abundance scale (r = rare; + = common but less than 1 % cover; 1 = 1-5%; 2 = 6-25%; 3 = 25-50%; 4 = 51-75%; 5 = 76-100%)

Vegetation at the Toolik Lake permanent plots

Figure 3. Vegetation at one of the Toolik Lake permanent plots (Plot SWT-72).

 

Soil profile at the Toolik Lake permanent plots

Figure 4. Soil profile at one of the Toolik Lake permanent plots (Plot SWT-16).

This data set was provided by the GINA repository at http://geobotanical.portal.gina.alaska.edu/plot-archive/plot-datasets/33-toolik-lake; access date 29 June 2016. For additional background information on this data set please refer to http://www.arcticatlas.org/support/tldatareport/index.

 

Data Access

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

Pre-ABoVE: Arctic Vegetation Plots at Toolik Lake, Alaska, 1989

Contact for Data Center Access Information:

References

Hobbie, J. E., & Kling, G. W. (Eds.). (2014). Alaska's changing Arctic: Ecological consequences for tundra, streams, and lakes. Oxford University Press.

Shippert, M. M., Walker, D. A., Auerbach, N. A., & Lewis, B. E. (1995). Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska. Polar Record, 31(177), 147-154.

Walker, D. A., F. J. A. Daniëls, I. Alsos, U. S. Bhatt, A. L. Breen, M. Buchhorn, H. Bültmann, L. A. Druckenmiller, M. E. Edwards, D. Ehrich, H. E. Epstein, W. A. Gould, R. A. Ims, M. H, M. K. Raynolds, J. Sibik, and S. S. Talbot. 2016a. Arctic vegetation: A hierarchic review of productivity, biodiversity patterns and an Arctic vegetation archive. Environmental Research Letters

Walker, D. A.; A. L. Breen; L. A. Druckenmiller; L. W. Wirth; W. Fisher; M. K. Raynolds; J. Šibík; M. D. Walker; S. Hennekens; K. Boggs; T. Boucher; M. Buchhorn; H. Bültmann; D. J. Cooper; F. J.A Daniëls; S. J. Davidson; J. J. Ebersole; S. C. Elmendorf; H. E. Epstein; W. A. Gould; R. D. Hollister; C. M. Iversen; M.T. Jorgenson; A. Kade; M. T. Lee; W. H. MacKenzie; R. K. Peet; J. L. Peirce; U. Schickhoff; V. L. Sloan; S. S. Talbot; C. E. Tweedie; S. Villarreal; P. J. Webber; D. Zona. The Alaska Arctic Vegetation Archive. 2016b. Phytocoenologia doi: http://dx.doi.org/10.1127/phyto/2016/0128  

Walker, D.A. (Ed). Alaska Arctic Vegetation Archive Workshop, Boulder, Colorado, October 14-16, 2013. CAFF Proceedings Report #11. Akureyri, Iceland. ISBN: 978-9935-431-29-5.

Walker, D. A., A. L. Breen, M. K. Raynolds, and M. D. Walker, editors. 2013. Arctic Vegetation Archive Workshop, Krakow, Poland April 14-16, 2013. CAFF Proceedings Report #10. Akureyri, Iceland. ISBN: 978-9935-431-24-0.

Walker, D. A., and M. K. Raynolds. 2011. An International Arctic Vegetation Database: A foundation for panarctic biodiversity studies. CAFF Strategy Series Report nr. 5. Conservation of Arctic Flora and Fauna (CAFF), Akureyri, Iceland.

Walker, D. A., Auerbach, N. A., & Shippert, M. M. (1995). NDVI, biomass, and landscape evolution of glaciated terrain in northern Alaska. Polar Record, 31(177), 169-178.

Walker, M. D., Walker, D. A., & Auerbach, N. A. (1994). Plant communities of a tussock tundra landscape in the Brooks Range Foothills, Alaska. Journal of Vegetation Science, 5(6), 843-866.

Walker D.A. and Barry N. (1991). Toolik Lake permanent vegetation plots: site factors, soil physical and chemical properties, plant species cover, photographs, and soil descriptions. Data Report 48, Department of Energy R4D Program, Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO.