Arctic Vegetation Plots at Umiat, North Slope, Alaska, 1951

This data set provides vegetation cover and plot data collected during the periods of July and August, 1951, from 51 stands (areas of homogeneous vegetation communities) in the the Umiat region of Alaska, on the Colville River. The Umiat area is within the Northern Foothills section of the Arctic Foothills province on the slope north of the Brooks Range. Data include vegetation species, percent cover classes, soil moisture, topographic position, slope, aspect, and plot shape and size.

The study plots were subjectively located in plant communities that occurred in six broad habitat types. A modified Hult-Sernander scale was used to determine the vegetation percent cover classes. The data are provided according to the original source (Churchill, 1955) and also according to the listings provided in TURBOVEG, a database for managing vegetation-plot data (see http://www.synbiosys.alterra.nl/turboveg/).

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

This data set provides vegetation cover and plot data collected in 1955 from the Umiat region of Alaska. Early vegetation sampling on Alaska's North Slope was undertaken by Ethan D. Churchill while stationed at Umiat on the Colville River. Field work was conducted in July and August of 1951 to identify plant communities and to determine their relationship to environmental conditions.

Vegetation species are listed and percent cover classes are provided according to a modified Hult-Sernander scale. Plot data includes moisture, topographic position, slope, aspect, shape, and size.

The data are provided according to the original source (Churchill, 1955) and also according to the listings provided in TURBOVEG, a database for managing vegetation-plot data (see http://www.synbiosys.alterra.nl/turboveg/).

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) iis a NASA Terrestrial Ecology Program field campaign that will take place 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 files were edited by Donald A. Walker, Amy L. Breen and Lisa A. Druckenmiller at the University of Alaska Fairbanks' Alaska Geobotany Center and obtained via the Arctic Geoecological Atlas (http://arcticatlas.geobotany.org/), which provides access to existing Arctic vegetation plot and map data in support of the ABoVE campaign.  

Spatial Coverage: Umiat, Alaska

ABoVE Grid Location: Ahh1Avv0

Spatial Resolution: Point resolution

Temporal Coverage: 1951-07-01 to 1951-08-31

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
Umiat, Alaska	-152.13	-152.13	69.37001	69.37001

 

Data File Information

There are two data files with this data set in comma-separated (.csv) format. The files provide the vegetation species found at 51 plots as well as the percent ground cover occupied by the species and plot data. These data may also be found in the TURBOVEG database. The files include the TURBOVEG accession numbers as well as the original plot nomenclature and numbering. There are also three companion files which provide plot photos and research information.

 

Table 1. Data files

Data File Name	Description
Umiat_Environmental_Data.csv	Plot data including soil code, moisture, slope, aspect, and topography data. Also includes percent groundcover from Mosses and Lichens
Umiat_Species_Data.csv	The estimated percent land cover by species per plot according to a modified Hult-Sernander scale. The plots are named according to the original stand numbers and the TURBOVEG accession numbers.
Companion files	Description
Umiat_Plot_Photos.pdf	Photos of the plots at Umiat in .pdf format
Umiat_Veg_Plots.pdf	A pdf of this guide document

 

Table 2. Variables in the file Umiat_Environmental_Data.csv

Column number	Variable	Units/format	Description
1	FIELD_RELEVE_NUM
2	DATE	YYYY	Survey date=1951
3	MOSSES_LIVERWORTS_CODE
4	LICHENS_CODE
5	TOT_NUM_VASCULAR_SPECIES_QUADRATS
6	AV_NUM_VASCULAR_SPECIES_QUADRAT
7	HOMOGENEITY-INDEX
8	FREQUENCY-HOMOGENEITY_TEST
9	STAND_AREA	m2
10	PLOT_SHAPE		All plots are reported as “square”
11	COMMUNITY_TYPES_SUBTYPE
12	SOIL_CODE
13	SITE_MOISTURE
14	SLOPE	degrees
15	ASPECT
16	TOPOGRAPHIC_POSITION
17	STAND_LOCATION_DESCRIPTION		General description of the plot

 

Table 3. Variables in the file Umiat_Species_Data.csv

Column number	Column header	Description
1	PASL_TAXON_SCIENTIFIC_ NAME	Current nomenclature according to the Panarctic Species List (PASL)
2	PASL_TAXON_SCIENTIFIC_ NAME_AU	Current nomenclature according to the Panarctic Species List (PASL) with the data authors (AU) name
3	DATASET_TAXON	Data set taxonomy
4-55	TURBOVEG_NUM and DATASET_PLOT_ NUM	Two rows of 51 column headers. The first row is TURBOVEG accession numbers. Column headers= 12942-12992. The 2nd row is DATASET_PLOT_ NUM, the plot numbers as named in the original data set; column headers= STAND_#. For example, STAND_ 70. The data values are the estimated percent land cover by species per plot according to a modified Hult-Sernander scale where: 0= (none present) + (trace or 0.5 percent) 1 (covers less than 1/6) 2 (covers 1/6 to 1/8) 3 (covers 1/8 to 1/4) 4 (covers 1/4-1/2) 5 (covers 1/2 to 3/4) 6 (covers 3/4 to 4/4) Example data are provided in Table 4 below.

 

Table 4. Example data from the file Umiat_Species_Data.csv

		TURBOVEG_ NUM	12942	12943	12944	12945
		DATASET_ PLOT_NUM	STAND_70	STAND _8	STAND_2	STAND_63
PASL_TAXON_SCIENTIFIC_ NAME	PASL_TAXON_SCIENTIFIC_ NAME_AU	DATASET_ TAXON
Alnus viridis s. crispa	Alnus viridis s. crispa (Dryl. ex Aiton) Turrill	Alnus crispa		1	1	0
Andromeda polifolia	Andromeda polifolia L.	Andromeda polifolia	0	1	0	0
Anemone richardsonii	Anemone richardsonii Hook.	Anemone richardsonii	0	0	0	0
Antennaria rosea s. pulvinata	Antennaria rosea s. pulvinata (Greene) R. J. Bayer	Antennaria isolepis	0	0	0	0
Arctagrostis latifolia	Arctagrostis latifolia (R. Br.) Griseb.	Arctagrostis latifolia	1	1	0	0

Note: In five instances, taxa were lumped into a single taxon in the PASL: 1) Carex bigelowii s. ensifolia (Carex consimili and Carex lugens), 2) Equisetum arvense s. alpestre (Equisetum arvense var. boreale and Equisetum arvense var. boreale f. pseudo-varium), 3) Salix niphoclada (Salix brachycarpa var. mexiae and Salix niphoclada), 4) Salix glauca s. acutifolia (Salix desertorum, Salix glauca var. acutifolia, Salix glauca var alisceae), and 5) Salix pulchra (Salix pulchra and Salix pulchra var. palmeri).

These data represent a historical snapshot of conditions on the North Slope in the mid-20th century. They could be useful for studies of vegetation and land cover change and also for climate models.

Stands were not permanently marked and very little plot-specific environmental data were recorded.

Modifications to the source data:

1) A verbal description of aspect was converted to degrees and then crosswalk to TURBOVEG categorical data. Where slope was 0 and aspect was lacking, aspect values were converted to -1 “too flat to determine”.

2) Cover of mosses, lichens, and bare ground were converted from the modified Hult-Sernander scale codes (pluses and minuses were dropped due to lack of assigned value) to fractional ranges given in the text (Churchill, 1955). The midpoint in the fractional range was taken and converted to a cover percentage as indicated:

+ (trace or 0.5 percent),

1 (covers less than 1/6 of the area or 4 percent),

2 (covers 1/6 to 1/8 or 9 percent),

3 (covers 1/8 to 1/4 or 18 percent),

4 (covers 1/4 to 1/2 or 38 percent),

5 (covers 1/2 to 3/4 or 63 percent),

6 (covers 3/4 to 4/4 or 87 percent).

3) The pluses and minuses associated with cover values as presented in the publication were dropped (although not where plus alone indicates a trace) as these symbols were not assigned a value.

4) Habitat types and site moisture were assigned by D.A. ‘Skip’ Walker in January 2016.

5) Location data were not available for the plots so all were assigned the latitude and longitude for Umiat.

Site description

The Umiat area is within the Northern Foothills section of the Arctic Foothills province on the slope north of the Brooks Range. The general topography of the upland is gently rolling hills and moderately flat valleys. The climate of the Umiat area is rigorous. The average annual temperature is 10.7 degrees F; the lowest recorded temperature was -63 degrees during February, the highest was 85 degrees during July, and the mean monthly temperature was below 0 degrees for the period December through April (Churchill, 1955).

The tundra vegetation of the Umiat area displays in many cases variation within a few feet or inches, probably as a result of the variation in environmental conditions accompanying a few inches difference in microrelief and resulting in a mosaic of microstands. Each stand has a homogeneity of micromosaics that is distinctive over a given area and is dissimilar to the distinctive homnogeneities of adjacent area. The elevation on the floodplain at Umiat is approximately 340 feet. Elevations of the ridges and tops of hills of the upland extend to 950 feet (Churchill, 1955).

Figure 2. Aerial view of the river and floodplain at Umiat, Alaska.

 

Vegetation Species

Early vegetation sampling on Alaska's North Slope was undertaken by Ethan D. Churchill while stationed at Umiat on the Colville River. Field work was conducted in July and August of 1951 to identify plant communities and to determine their relationship to environmental conditions.

In July and August of 1951, 51 stands (areas of unified vegetation) were subjectively located and sampled. Stands were determined by aerial photography and ground reconnaissance to ensure homogeneity. Ten, 1-square meter plots were systematically located as uniformly and widely as possible within homogeneous vegetation of the stand but restricted so that transitional areas into adjacent stands were avoided. Plant species cover was recorded using a modified Hult-Sernander scale where:

0 (none present),

+ (trace or 0.5 percent),

1 (covers less than 1/6),

2 (covers 1/6 to 1/8),

3 (covers 1/8 to 1/4),

4 (covers 1/4-1/2),

5 (covers 1/2 to 3/4), and

6 (covers 3/4 to 4/4).

 

Plant communities occurred in broad habitat types including:

1) Willow shrub vegetation of riparian areas and warm habitats (south-facing slopes) (2 plots),

2) Moist to wet acidic tussock and nontussock (Eriophorum vaginatum-Carex bigelowii-Sphagnum-Hylocomium) tundra (40 plots),

3) Dry acidic prostrate-shrub heaths (Arctous alpina, Salix phlebophylla, Empetrum heaths) (2 plots),

4) Frost boil vegetation in nonacidic tundra (Juncus biglumis, Saxifraga oppositifolia) (2 plots),

5) Alder communities (2 plots), and 6) Sedge grass and dwarf shrub mire and fen vegetation (3 plots) (Churchill, 1955).

 

Plot characterization data are also included with this data set. However, location data were not available for the plots so all were assigned the latitude and longitude for Umiat.

 

Environmental Data

Churchill (1955), references Payne et al. (1951), Smith and Mertie (1930), Stenfansson and Whittington (1947), and Black and Barksdale (1948) regarding the geology and topography of the area. 

Habitat types and site moisture were assigned by the primary contact  D. A. ‘Skip’ Walker, in January 2016.

Black, R. F., and W. L. Barksdale. 1948. Terrain and permafrost, Umiat Area, Alaska. Progress Report No. 5, Military Geology Section, U. S. Geol. Surv. Washington. 23 p.

Churchill, E. D. 1955. Phytosociological and environmental characteristics of some plant communities in the Umiat region of Alaska. Ecology. 36:606-627.

Payne, T. G., W.W. Dana, W. A. Fischer, George Gryc, E.H. Lathram, R.H. Morris, H.N. Tappan, and S.T. Yusler. 1951. Geology of the Arctic Slope of Alaska. Oil and Gas Investigations, Map 126 Sheet 1. U. S. Geol. Surv., Washington.

Smith, P. S., and J. B. Mertie, Jr. 1930. Geology and mineral resources of northwestern Alaska. U. S. Geol. Surv. Bull. 815. 351 p.

Stenfansson, K., and C. L. Whittington. 1947. Stratigraphy and structure of the Umiat anticline. Report No. 3, Geological Investigations Naval Pet. Res. No. 4, Alaska. U. S. Geol. Surv. Washington. 11 p.