Arctic Vegetation Plots on Unalaska Island, Aleutian Islands, Alaska, 2007

This data set provides environmental, soil, and vegetation data collected during August 2007 from 69 study plots at the Unalaska Island research site, and one plot on Amaknak Island. The study sites are within the eastern Aleutian Islands, Alaska, USA. Data includes the plot information for vegetation, soils, and site characteristics for the study plots subjectively located in 11 plant communities that occur in six broad habitat types. Specific attributes include: dominant vegetation species and cover, soil chemistry, moisture, organic matter, topography, and elevation. Cover-abundance was estimated for all vascular plants, bryophytes, and macrolichens according to the nine-point ordinal scale of Westhoff and van der Maarel (1973).

The data are provided according to the original source and also according to the listings provided in the TURBOVEG data base, a software program 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.

In 2007, one of the first quantitative studies of vegetation from sea level to alpine on Unalaska Island in the Aleutian Islands was completed (Talbot et al., 2010). The focus of the study was to 1) describe the major plant communities along environmental gradients, 2) identify the main vegetation types and communities and determine their relationship to select site factors, and 3) compare these communities to other studies completed in southern Alaska.

This data set provides vegetation cover and environmental plot data collected in 2007 from Unalaska Island. Vegetation species are listed and percent cover classes are provided according to the Westhoff and van der Maarel (1973) scale. Plot data includes moisture, topographic position, slope, aspect, shape, and soil data.

The data are provided according to the original source and also according to the listings provided in the TURBOVEG data base, a software program 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.

Related Publication:

Talbot, S.S., W.B. Schofield, S.L. Talbot, and F.J.A. Daniels. 2010. Vegetation of Eastern Unalaska Island, Aleutian Islands, Alaska. Botany, 88(4): 366-388, http://dx.doi.org/10.1139/B09-113

Acknowledgements:

Funding for this project came from the U.S. Fish and Wildlife Service.

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: Unalaska Island, Aleutian Islands, Alaska

ABoVE Grid Location: outside of grid

Spatial Resolution: Point resolution

Temporal Coverage: 2007-08-03 to 2007-08-22

Temporal Resolution: Each plot was sampled once

Study Area (All latitude and longitude given in decimal degrees, WGS84 datum )

Site	Westernmost Longitude	Easternmost Longitude	Northernmost Latitude	Southernmost Latitude
Unalaska Island, Aleutian Islands	-166.518	-166.44	53.90875	53.84094

 

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 70 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.

Table 1. Data files

Data File Name	Description
Unalaska_Environmental_Data.csv	Plot data including soil code, moisture, slope, aspect, and topography data. Also includes percent groundcover from Mosses and Lichens
Unalaska_Species_Data.csv	The estimated percent land cover by species per plot according to the nine-point ordinal scale developed by Westhoff and van der Maarel (1973) scale where: 0= (none present) 1 (covers less than 1%) 2 (covers 1 %) 3 (covers 2 to 3%) 4 (covers 4-5%) 5 (covers 6 to 12%) 6 (covers 13 to 24%) 7 (covers 25 to 49%) 8 (covers 50 to 74%) 9 (covers 75 to 100%) The plots are named according to the original stand numbers and the TURBOVEG accession numbers

 

Table 2. Variables in the file Unalaska_Environmental_Data.csv

Column number	Variable	Units/format	Description
1	FIELD_RELEVE_NUM_AU		Releve number as provided by the author (AU)
2	PUBLISHED_RELEVE_NUMBER	PUBLISHED_RELEVE_NUMBER	Releve number as published
3	SITE_VISIT_DATE	YYYYMMDD	Date plot was investigated
4	SPECIFIC_LOCATION		Directions to the site
5	LATITUDE	decimal degrees	Plot latitude
6	LONGITUDE	decimal degrees	Plot longitude
7	PLOT_SIZE	m	Plot sizes were 5 x 5 meters
8	TOPOGRAPHY		Topography of site
9	ELEVATION	m	Elevation of site
10	SLOPE	degrees	Slope of site
11	PLANT_COMMUNITY_NAME		Plant community at the plot
12	SHRUB_0.5-2M	%	Percent of shrubs .5-2 m in the plant community
13	DWARF_SHRUB_LESS_THAN_0.5M	%	Percent of dwarf shrubs less than .5m in the plant community
14	GRAMINOID	%	Percent of graminoids in the plant community
15	FORB	%	Percent of forbs in the plant community
16	BRYOPHYTE	%	Percent of bryophytes in the plant community
17	LICHEN	%	Percent of lichens in the plant community
18	LITTER	%	Litter present, provided as a percent
19	ORGANIC_MATTER	g/kg	Soil organic matter provided in g/kg
20	PH_PASTE		Soil ph
21	ELECTRICAL_CONDUCTIVITY	DS/m	Soil electrical conductivity provided as deciSiemens per meter (DS/m)
22	NO3	PPM	Soil nitrate content provided in parts per million (PPM)
23	NH4	PPM	Soil ammonium content provided in parts per million (PPM)
24	P	PPM	Soil phosphorus content provided in parts per million (PPM)
25	SO2	PPM	Soil sulfur dioxide content provided in parts per million (PPM)
26	B	PPM	Soil boron content provided in parts per million (PPM)
27	Zn	PPM	Soil zinc content provided in parts per million (PPM)
28	Mn	PPM	Soil manganese content provided in parts per million (PPM)
29	Cu	PPM	Soil copper content provided in parts per million (PPM)
30	Fe	PPM	Soil iron content provided in parts per million (PPM)
31	K	PPM	Soil potassium content provided in parts per million (PPM)
32	Ca	cmol/kg	Soil calcium provided as centimoles per kg (cmol/kg) of soil
33	Mg	cmol/kg	Soil magnesium provided as centimoles per kg (cmol/kg) of soil
34	Na	cmol/kg	Soil sodium provided as centimoles per kg (cmol/kg) of soil
35	TOTAL_BASES	cmol/kg	Total of all bases provided as centimoles per kg (cmol/kg) of soil
36	ECOLOGICAL_MOISTURE_CODE	numeric	Moisture code=1 - 7
37	ECOLOGICAL_MOISTURE_REGIME		Moisture regime = subhydric, mesic, subxeric, xeric, submesic, or hydric

 

Table 3. Variables in the file Unalaska_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 70 column headers. The first row is TURBOVEG accession numbers. Column headers= 12792-12861. The 2nd row is DATASET_PLOT_ NUM, the plot numbers as named in the original data set column headers = numbers 1 - 70. The data values are the estimated percent land cover by species per plot according to the nine-point ordinal scale developed by Westhoff and van der Maarel (1973) scale where: 0= (none present) 1 (covers less than 1%) 2 (covers 1 %) 3 (covers 2 to 3%) 4 (covers 4-5%) 5 (covers 6 to 12%) 6 (covers 13 to 24%) 7 (covers 25 to 49%) 8 (covers 50 to 74%) 9 (covers 75 to 100%) Example data are provided in Table 4 below

 

Table 4. Example data from the file Unalaska_Species_Data.csv

Note: In 3 instances, taxa were lumped into a single taxon in the PASL: Cetraria islandica (Cetraria islandica s. crispiformis and Cetraria islandica s. islandica), Cladonia gracilis s. lat. (Cladonia gracilis s. elongata and Cladonia gracilis s. vulnerata), and Limnorchis hyperborea (Platanthera convallariaefolia and Platanthera stricta).

		TURBOVEG_NUM	12792	12793	12794	12795
		DATASET_PLOT_NUM	1	2	3	4
PASL_TAXON_SCIENTIFIC_NAME	PASL_TAXON_SCIENTIFIC_NAME_AU	DATASET_TAXON
Achillea millefolium s. borealis	Achillea millefolium s. borealis (Bong.) Breitung	Achillea millefolium v. borealis	0	0	1	2
Aconitum delphinifolium s. delphinifolium	Aconitum delphinifolium [s. delphinifolium] DC.	Aconitum delphinifolium	0	0	0	0
Aconitum maximum	Aconitum maximum Pallas ex de Candolle	Aconitum maximum	0	0	1	0
Agrostis exarata	Agrostis exarata Trin.	Agrostis exarata	0	0	0	0

These data could be useful for parameterizing land cover within models of the Arctic carbon cycle and in understanding changes in vegetation due to climate change in the Arctic.

Voucher specimens were deposited at several herbaria and determined or confirmed by specialists (Talbot et al., 2010).

Site description

The study area sites are within the eastern Aleutian Islands. The Aleutian Islands extend in an arc from the northwestern portion of the North American landmass 1,900 km into the Pacific Ocean toward Asia. Mean annual temperature is 4.5 degrees C and mean annual precipitation is 1,458 mm. The topography is rugged. Soils are Andisoils. Species dispersal occurs in at least two directions, westward from North America along the Aleutians and eastward from Asia toward Interior Alaska (Talbot et al., 2010).

Methods

From August 3rd to August 27th, 70 plots were established in units of homogeneous vegetation so as to represent conspicuous variation in plant communities. The plots were 5-m x 5-m in size. Cover-abundance was estimated for all vascular plants, bryophytes, and macrolichens according to the nine-point ordinal scale of Westhoff and van der Maarel (1973).

Environmental factors recorded were aspect (degrees), elevation (m, a.s.l.), litter cover (%), slope inclination (degrees), ecological moisture regime (ordinal values: 1, xeric; 2, subxeric; 3, submesic; 4, mesic; 5, subhygric; 6, hygric; 7, subhydric; and 8, hydric), and mesotopography. Latitude and longitude were recorded by GPS using WGS84 datum. One soil sample from the rooting zone was collected in the center of each relevé at a depth of 15–20 cm (Talbot et al., 2010).

Vegetation species

Eleven plant communities in six broad ecological groups were identified in this study. These plant communities occur in 6 broad habitat types including: 1) Dry coastal beach and sand dune vegetation (9 plots), 2) Willow, grass, fern, forb thickets (4 plots), 3) Wet acidic sedge, forb mire (9 plots), 4) Late snowbed communities (3 plots), 5) Moist and dry acidic dwarf-shrub and lichen heaths (Vaccinium uliginosum, Empetrum nigrum, Ledum decumbens, Spiraea beauverdiana, and Betula nana-lichen heaths (22 plots), and 6) Alder communities (23 plots).

Cover-abundance was estimated for all vascular plants, bryophyte, and macrolichens using the nine-point original scale of Westhoff and van der Maarel (1973) in sixty-nine subjectively chosen plots on Unalaska Island and one plot on Amaknak Island where:

0= (none present)
1 (covers less than 1%)
2 (covers 1 %)
3 (covers 2 to 3%)
4 (covers 4-5%)
5 (covers 6 to 12%)
6 (covers 13 to 24%)
7 (covers 25 to 49%)
8 (covers 50 to 74%)
9 (covers 75 to 100%)

Soil analysis

Soil analysis included pH, organic matter, K, Ca, Mg, Na, soil nitrate-N, ammonium-N, SO₄-S, Boron, Zn, Mn, Cu, and Fe. Soils were analyzed using an autoanalyzer and organic matter was determined by the Walkley-Black method. The orthophosphate analyte was determined using the Olsen extraction method (Talbot et al., 2010).

Talbot, S.S., W.B. Schofield, S.L. Talbot, and F.J.A. Daniels. 2010. Vegetation of Eastern Unalaska Island, Aleutian Islands, Alaska. Botany, 88(4): 366-388, http://dx.doi.org/10.1139/B09-113

Westhoff, V. and E. van der Maarel. 1973. The Braun-Blanquet approach. In Handbook of Vegetation Science (Ed. R. Tüxen) Part V. Ordination and Classification of Communities (ed. R. H. Whittaker), p. 617-726. Junk, The Hague.