ARCSS040: Air Temperature and Thaw Depth, North Slope, Alaska: Field Measurements (1995-97) and Computed Values General Site Descriptions (see the detailed site information following these descriptions for specific vegetation and soil details for sites 1-10): Deadhorse N70 degrees 11.43 minutes, W148 degrees 28.99 minutes; elevation 16 m. Mast was adjacent to a thermokarsted road in wet tundra. 95-1 N70 degrees 17.01 minutes, W148 degrees 53.57 minutes; elevation 12 m. Moist non-acidic tundra and wet nonacidic tundra, mixed low- and flat-centered ice-wedge polygons. 95-2 N70 degrees 16.50 minutes, W148 degrees 55.14 minutes; elevation 12 m. Wet non-acidic tundra, low-centered polygons. 95-3 N69 degrees 26.46 minutes, W148 degrees 40.22 minutes; elevation 269 m. Moist non-acidic tundra, featureless hillslope. 95-4 N69 degrees 26.06 minutes, W148 degrees 48.34 minutes; elevation 360 m. Moist acidic tundra, featureless hillslope. 95-5 N68 degrees 45.76 minutes, W149 degrees 24.77 minutes; elevation 1142 m. Dry, barren, gently sloping, alpine fellfield. 95-6 N68 degrees 37.44 minutes, W149 degrees 37.09 minutes; elevation 777 m. Water track/moist acidic tundra complex. 95-7 N68 degrees 36.66 minutes, W149 degrees 18.87 minutes; elevation 917 m. Acidic wetland/colluvial basin complex. 95-8 N68 degrees 36.66 minutes, W149 degrees 18.56 minutes; elevation 938 m. Moist acidic tundra/weakly developed water track complex. 95-9 N69 degrees 03.87 minutes, W148 degrees 44.93 minutes; elevation 349 m. Moist non-acidic riparian shrubland. Flat island in Sagavanirktok River. 95-10 N69 degrees 07.73 minutes, W148 degrees 35.57 minutes; elevation 537 m. Wet/moist water track shrublands. Mile 56 Mile 56 on the Dalton Highway, wet tundra. Detailed Site Information: Air Temperature Data: Flux Study Plots, Kuparuk River Basin, 1995-97 Vegetation-Soil Site Characterization At The 12 Flux Tower Sites: PARTICIPANTS: Skip Walker and Alisa Gallant (vegetation); Jim Bockheim, Jeff Munroe, and Lynn Everett (soils) PERIOD OF STUDY: 12-26 August 1995 PURPOSE: To characterize and map the vegetation and soils at 10 flux tower sites of Terry Chapin et al. and two flux towers of Walt Oechel et al. METHODS: Transects: Each site consists of a 100x100-m square with corners and centerpoint (flux tower site) marked in the field with air photo panels and 4-ft lath. 6 transects (4 50-m and 2 70-m transects) radiating from the centerpoint are marked with wire flags spaced at 5-m intervals. Vegetation: Species composition, moss thickness, vegetation height: Species occurrence at the top and bottom of the plant canopy was sampled at each meter along the 6 transects using a Buckner optical point sampling device.Canopy height was sampled along the 6 transects at 1-m intervals by measuring to the height of a point intersected in the plant canopy at each meter mark along a measuring tape. Moss thickness was measured at 5-m intervals along each transect by removing a small plug of moss and measuring the thickness of the live green portion. Vegetation communities: A list of vegetation communities were made for each site. The location of communities, maximum shrub heights within the communities, and transitions between communities were recorded along each transect. Releves (vegetation samples using the Braun-Blanquet approach) were obtained for each of the major communities by recording the cover-abundance of all of the vascular, bryophyte, and lichen species within approximately 10x10-m areas. Site factors (surficial geomorphology,parent material, and subjective ratings of soil moisture, site moisture,snow regime, exposure, aspect, slope, etc.) Normally, 2-3 releves were obtained for each site. Soil pits on equivalent sites were described by Jim Bockheim. Vegetation and soil maps of each site will be prepared based on the transect information and photo-interpretation of the CIR photographs. Soils: Small soil pits were dug by hand along the six transects at 10-meter intervals and at the plot center for a total of 49 pits. Measurements included thickness of the organic horizon and thawing depth. Each soil was classified, and a large-scale soil map was generated for each site. At each site from one to four soil pits measuring 1 meter by 1 meter were dug by hand to the frozen surface at and with a gasoline powered chisel to 100 cm.Detailed soil descriptions were made and samples were collected for field moisture content, bulk density, and chemical/physical analyses. RESULTS: Site descriptions, vegetation, and soil: Site 1. Betty Pingo, moist site. Location: Coastal Plain, Prudhoe Bay region, N70 17.01, W148 53.57, elev.12 m. Site description: Flat with mixed flat-centered and low-centered polygons;moist nonacidic tundra. Vegetation communities: (1) Raised microsites, including polygon rims and raised centers: Moist Eriophorum triste, Carex membranacea, Dryas integrifolia, Tomentypnum nitens, Thamnolia subuliformis graminoid, prostrate-shrub tundra. (2) Lower microsites, mainly polygon basins: Wet Eriophorum angustifolium, Carex aquatilis, Drepanocladus brevifolius graminoid tundra.Cover of top 5 species: Eriophorum triste (22%), Dryas integrifolia (16%),Tomentypnum nitens (7%), Eriophorum vaginatum (4%), Carex aquatilis (2%). Mean vegetation height: 3.1 +/- 3.0 s.d. cm Mean live moss layer thickness: 1.8 +/- 0.9 cm Soil taxa: Pergelic Cryoborolls (55%), P. Cryaquolls (16%), P. Cryaquepts (16%), others (13%). Organic layer thickness: 12 +/- 1.7 S.E. cm. Thaw depth: 41 +/- 1.2 cm. Site 2. Betty Pingo, wet site. Location: Coastal plain, Prudhoe Bay region, N70 16.50, W148 55.14, elev. 12m. Site description: Flat with low-centered polygons; wet nonacidic tundra. Vegetation communities: (1) Lower microsites, including polygon basins and troughs: Wet Eriophorum angustifolium, Carex aquatilis, Scorpidium scorpioides graminoid tundra. (2) Raised microsites, including polygon rims and hummocks: Moist Eriophorum triste, Dryas integrifolia,Tomenthypnum nitens graminoid, prostrate-shrub tundra. Cover of top 5 species: Eriophorum angustifolim (28%), Scorpidiumscorpioides (11%), Carex aquatilis (10%), Drepanocladus brevifolius (3%),Dryas integrifolia (3%) Mean vegetation height: 4.1 +/- 3.9 cm Mean live moss layer thickness: 0.8 +/- 0.7 cm Soil taxa: Histic Pergelic Cryaquolls (39%), P. Cryaquolls (25%), P. Cryofibrists (24%), others (12%). Organic layer thickness: 25 + 1.5 cm. Thaw depth: 44 + 1.6 cm. Site 3. Sagwon, moist nonacidic site. Location: Northern Foothills, Sagwon vicinity, N69 26.46, W148 40.22,elev. 269 m. Site description: Hill, gentle northwest-facing slope (4 degrees) with nonsorted circles; moist nonacidic tundra. Vegetation communities: (1) Vegetated nonsorted circles: Moist Eriophorum triste, E. vaginatum, Dryas integrifolia, Hylocomium splendens, Racomitrium lanuginosum, Thamnolia subuliformis graminoid, prostrate-shrub tundra. (2) Barren nonsorted circles: Dry Saxifraga oppositifolia, Juncus biglumis, Ochrolechia frigida forb, crustose-lichen barren (3) Areas between nonsorted circles: Moist Dryas integrifolia, Salix reticulata, Eriophorum triste, Tomentypnum nitens, prostrate-shrub, graminoid, moss tundra. Cover of top 5 species: Carex bigelowii (20%), Dryas integrifolia (14%),Eriophorum triste (14%), Hylocomium splendens (10%), Eriophorum vaginatum(9%) Mean vegetation height: 3.9 +/- 4.6 cm Mean live moss layer thickness: 2.1 +/-1.4 cm Soil taxa: Pergelic Cryaquolls (43%), P. Cryaquepts (18%), P. Cryoborolls(14%), others (25%). Organic layer thickness: 9 + 1.2 cm. Thaw depth: 57 + 1.4 cm. Site 4. Sagwon, moist acidic site. Location: Northern Foothills, Sagwon Upland, N69 24.06, W148 40.22, elev. 360m. Site description: Flat hill crest, featureless, moist acidic tundra. Vegetation communities: Moist Eriophorum vaginatum, Betula nana, Salix pulchra, Hylocomium splendens tussock-graminoid, dwarf-shrub tundra. Cover of top 5 species: Eriophorum vaginatum (24%), Ledum decumbens (9%), Betula nana (9%), Hylocomium splendens (8%), Salix pulchra (6%) Mean vegetation height: 5.9 +/- 6.4 cm Mean live moss layer thickness: 2.2 +/- 1.4 cm Soil taxa: Pergelic Cryaquepts (79%), Histic Pergelic Cryaquepts (21%). Organic layer thickness: 15 + 0.9 cm. Thaw depth: 37 + 1.0 cm. Site 5. Imnavait Mountain, dry acidic site. Location: Southern Foothills, Imnavait Mountain, N68 37.44, W149 37.09,elev. 1142 m. Site description: Gentle (7 degrees) southwest-facing slope near summit of mountain, weathered sandstone and conglomerate bedrock (Fortress Mountain Formation); dry acidic tundra. Vegetation communities: (1) Exposed sites: Dry Salix phlebophylla, Douglasia ochotensis, Alectoria nigricans prostrate-shrub, cushion-forb,lichen barren. (2) Slightly protected sites: Moist Salix phlebophylla,Carex microchaeta, Polytrichum piliferum prostrate-shrub, graminoid tundra.Cover of top 5 species: Rhizocarpon sp. (9%), Salix phlebophylla (7%),White crustose lichen (4%), Seleginella sibirica (4%), Cetraria nigricans (3%). Mean vegetation height: 0.1 +/- 0.3 cm Mean live moss layer thickness: 0.1 +/- 0.2 cm Soil taxa: Pergelic Cryochrepts (98%), P. Cryumbrepts (2%). Organic layer thickness: trace. Thaw depth: >100 cm. Site 6. Toolik Lake, water-track complex. Location: Southern Foothills, Toolik Lake vicinity, N68 37.44, W149 37.09,elev. 777 m. Site description: Gentle (3 degrees) north-facing slope, including watertrack and nonsorted circles (site of LTER weir, Joe McFadden's thesis experiment, and several other studies); moist acidic tundra and water-track complex. Vegetation communities: (1) Tussock tundra areas between nonsorted circles: Moist Eriophorum vaginatum, Betula nana, Hylocomium splendens tussock-graminoid, dwarf-shrub tundra. (2) Vegetated nonsorted circles: Dry Vaccinium vitis-idaea, Racomitrium lanuginosum, Cladina arbuscula prostrate-shrub, fruticos-lichen tundra. (3) Barren nonsorted circles: Dry Luzula arctica, Juncus, Anthelia juratzkana barren. (4) Water tracks: Wet Salix pulchra, Eriophorum angustifolium low-shrub tundra. (5) Shrub by water-track margins: Moist Betula nana, Rubus chamaemorus, Sphagnum girgohnsohnii dwarf-shrub tundra. (6) Water-track transitions: Wet Salixpulchra, Rubus chamaemorus, Sphagnum sp. dwarf-shrub tundra.Cover of top 5 species: Eriophorum vaginatum (16%), Vaccinium vitis-idaea(12%), Betula nana (10%), Hylocomium splendens (9%), Ledum decumbens (7%) Mean vegetation height: 5.8 +/- 7.7 cm Mean live moss layer thickness: 1.8 +/- 1.0 cm Soil taxa: Pergelic Cryaquepts (73%), Histic Pergelic Cryaquepts (27%). Organic layer thickness: 15 + 1.0 cm. Thaw depth: 45 + 1.6. Site 7. Imnavait Creek, wet acidic site. Location: Southern Foothills, Imnavait Creek watershed, N68 36.66, W14918.87, elev. 917 m. Site description: Gentle (1 degree) north facing basin deposit with strangmoor, wetland hummocks, palsas; wet acidic tundra.Vegetation communities: (1) Raised microsites in basin including hummocks and palsas: Wet Carex rotundata, C. rariflora, Betula nana, Salix fuscescens, Sphagnum lenense graminoid, dwarf-shrub tundra. (2) Footslope of west-facing hill: Moist Betula nana, Eriophorum vaginatum, Sphagnum spp. dwarf-shrub, tussock-graminoid tundra. (3) Lower microsites in basin including interhummock areas with standing water: Wet Eriophorum scheuchzeri, Carex rotundata, Sphagnum orientale, Drepanocladus revolvens graminoid tundra. (4) Marginal area of the basin with few shrubs: Wet Carex rotundata, Salix fuscescens, Sphagnum lenense graminoid, moss tundra. (5) Beaded pond of Imnavait Creek: Aquatic Sparganium hyperboreum, Hippuris vulgaris forb marsh. Cover of top 5 species: Sphagnum lenense (13%), Carex rotundata (8%),Sphagnum warnstorfii (7%), Betula nana (6%), Sphagnum orientale (6%) Mean vegetation height: 2.2 +/- 3.2 Mean live moss layer thickness: 2.0 +/- 1.0 Soil taxa: Histic Pergelic Cryaquepts (54%), P. Cryofibrists (35%), P.Cryaquepts (10%). Organic layer thickness: 34 + 1.7 cm. Thaw depth: 55 + 1.7. Site 8. Imnavait Creek, moist acidic site with watertracks. Location: Southern Foothills, Imnavait Creek watershed, N68 36.66, W14918.56, elev. 938 m. Site description: Lower hillslope (15 degrees west-facing) with watertracks, scattered glacial erratics and nonsorted circles, moist acidic tundra, shrublands in water tracks (site of R4D studies, Kaye Everett's water-track weir) Vegetation communities: Inter-water-track areas: (1) Moist Eriophorum vaginatum, Ledum decumbens, Vaccinium vitis-idaea, Sphagnum girgensohnii tussock-graminoid, dwarf-shrub tundra. (2) Water tracks: Wet Salixpulchra, Rubus chamaemorus, Sphagnum angustifolium low-shrub tundra, and moist Betula nana, Rubus chamaemorus, Sphagnum spp. dwarf-shrub tundra. Cover of top 5 species: Eriophorum vaginatum (12%), Betula nana (11%), Vaccinium vitis-idaea (9%), Carex bigelowii (8%), Ledum decumbens (6%) Mean vegetation height: 3.6 +/- 3.6 Mean live moss layer thickness: 2.5 +/- 1.1 Soil taxa: Pergelic Cryaquepts (82%), Histic Pergelic Cryaquepts (18%). Organic layer thickness: 15 + 1.9 cm. Thaw depth: 43 + 1.2. Site 9. Sagavanirktok River, riparian shrubland Location: Northern Foothills, Happy Valley region, N69 03.87, W148 44.93,elev. 349 m. Site description: Island in braided river complex of Sagavanirktok River flood plain, flat with some abandoned channels through the island, riparian shrubland. Vegetation communities: (1) Flat areas: Dry Salix glauca, S. lanata, Arctous rubra, Hedysarum mackenzii, Hylocomium splendens low shrubland. (2) Small abandoned channels through the island: Moist Equisetumvariegatum, Carex capillaris, Distichium capilaceum barrens. Cover of top 5 species: Arctous rubra (23 %), Salix lanata (14%), Salixglauca (11%), Elymus innovatus (8%), Salix niphocladus (8%) Mean vegetation height: 18.4 +/- 19.8, Mean live moss layer thickness: 0.3 +/- 1.0 Soil taxa: Pergelic Cryorthents (100%). Organic layer thickness: 1 + 0.2 cm. Thaw depth: >192 cm. Site 10. Happy Valley, water-track complex Location: Northern Foothills, Happy Valley region, N69 07.73, W148 35.57,elev. 537 m. Site description: Well-developed water-track complex, southeast-facing slope (4 degrees); moist and wet acidic shrublands. Vegetation communities: (1) Interwater track areas: Moist Betula nana,Rubus chamaemorus, Hylocomium spendens low-shrub tundra. (2) Water tracks:Wet Salix pulchra, Eriophorum angustifolium, Sphagnum spp. low-shrub tundra. (3) Transitional areas to water tracks: Wet Salix pulchra, Betula nana, Rubus chamaemorus, Petasites frigidus, Carex bigelowii, Sphagnum spp.low-shrub tundra. Cover of top 5 species: Betula nana (27%), Hylocomium (20%), Salix pulchra(12%), Carex bigelowii (11%), Eriophorum vaginatum (5%)Mean vegetation height: 13.8 +/- 14.0 Mean live moss layer thickness: 3.2 +/- 1.1 Soil taxa: Histic Pergelic Cryaquepts (54%), P. Cryaquepts (46%). Organic layer thickness: 19 + 0.9 cm. Thaw depth: 46 + 1.2 cm.