SKIP WALKER, HOWIE EPSTEIN, BILL GOULD, STEVE MULLER

FIELD REPORT, SUMMER 1999

This report contains a brief summary of field activities on the Seward Peninsula and northern Alaska during 1 Jun to 18 Jul and a summary of the Canadian CAVM transect. 26 Jul to 13 Aug. The four figures can be downloaded using Freehand and Photoshop. (NOTE: The figures are not included as they are too large. If you would like the figures, please let me know and Skip can send them separately.)

The objective of the 1999 Ivotuk effort is to measure trends and establish relationships between biomass, LAI, and NDVI for zonal and other common vegetation types in the Arctic Foothills. This remote sensing component is in collaboration with Howie Epstein, University of Virginia. Monika Calef and David Richardson from University of Virginia monitored changes in LAI, NDVI, biomass and thaw at Ivotuk throughout the summer. Field protocols were established for sampling biomass, NDVI, LAI, and thaw depth on the four Ivotuk grids. Sampling was conducted biweekly from June 1 through August 31. Aboveground biomass harvests of 20 x 50 cm areas were collected at 10 randomly selected grid points within each of the four grids. Most vascular plants were clipped at the top of the moss surface. Moss and sedges were clipped at the base of the green layer. Sorting into six functional categories (shrubs, graminoids, forbs, horsetails, bryophytes, and lichens) was done in the field, and the samples were dried at Ivotuk and sent to University of Virginia for further sorting (evergreen and deciduous shrubs, herbaceous, woody, and dead components). LAI was measured using the Licor LAI-2000 instrument at 20 stratified random points. NDVI was measured at the same points using an Analytical Spectral Systems PS-2 spectrometer. Depth of the active layer was monitored monthly using the CALM protocols. It is anticipated that SDSU will fly at least one aircraft mission over Ivotuk this summer to collect aerial multispectral images with the ADAR instrument.

This work was in collaboration with Terry Chapin to select flux study sites near Council.

Eight 100 x 100 m grid sites were selected to characterize a conceptual topographic gradient in the Council vicinity and to provide a gradient of shrub and tree cover for monitoring energy and trace-gas fluxes in Chapin's project. Grids were established at four of the sites during our visit.

Potential Council Grids (ordered along a conceptual toposequence; Fig. 1):

1. Dry Dryas octopetala, Saxifraga oppositifolia, Cetraria cucullata,

prostrate dwarf shrub, lichen tundra (dry non-acidic tundra, DNT; Grid C-5) on a limestone ridge crest at 400 m. Corners of the grid were marked for aerial photography. Grid points will be put in next summer. Center of grid: N64∞43.550', W163∞56.589'. This site is difficult to access and an alternative site closer to Council should be considered.

2. Moist Carex bigelowii, Dryas octopetala, Salix glauca, low-shrub tundra savanna (moist non-acidic tundra, MNT; Grid C-7) on calcareous soils at transition to closed low-shrub tundra at 310m. The site was selected, but no grid was put in. The site is located about 200m north of Grid C-3 (see below).

3. Moist Betula glandulosa, Hylocomium splendens, low-shrub tundra (LST, Grid C-3). Located on south facing slope in broad expanse of low dwarf-birch shrublands at about 160 m elevation. The grid was established and the corners were marked for aerial photography. Coordinates: N64∞56.08', W163∞44.32'.

4. Moist Picea glauca, Hylocomium splendens, closed evergreen forest (EF; Grid C-1). Located on a south facing hill slope at about 100m elevation in an old second growth forest. Coordinates: N64∞54.41', W163∞40.68. The forest is thought to be structurally similar to old growth forests. The nearest old-growth forests are many kilometers from Council and were considered too remote for flux measurements. The grid was established and the corners were marked for aerial photography.

5. Moist Picea glauca, Salix planifolia ssp. pulchra, Calamagrostis canadensis, tall-shrub woodland (SW; Grid C-4). Located on a gentle slope at about 70 m elevation near Grid C-1 (see above) in the transition to valley bottom vegetation. The grid was established and the corners were marked for aerial photography. Coordinates: N64∞53.98', W163∞39.98'.

6. Moist acidic stripe complex (Grid C-6). This site is at the lower forest boundary in the transition to valley bottom vegetation. The site was selected to provide an acidic counterpart to Grid C-7 (see above) and to provide an intermediate shrub cover site for Catharine Copass' studies. The site is on a non-sorted stripe complex and is fairly heterogeneous. Catharine Copass will select a grid site later this summer.

7. Moist Eriophorum vaginatum, Betula nana, tussock-graminoid, dwarf-shrub tundra (Grid C-6). Tussock-tundra vegetation occurs on some lower hill slopes in the region. A grid site may be established in this vegetation next year.

8. Moist Cladonia spp., Ledum palustre ssp. decumbens, Carex ssp., fruiticose-lichen, dwarf shrub tundra (LH; Grid C-2). Located in a lichen heath in the valley bottom east of Council at about 35 m elevation. Grid was established and corners were marked for aerial photography. Coordinates: N64∞50.46', W163∞41.75'. This vegetation is common in valley bottoms in this region.

Three sites were selected at Quartz Creek on 12 June within Larry Hinzman's grid. On Jun 12, Amber Moody and marked three 100 x100-m grid cells within Larry Hinzman's 1000 x 1000-m grid at Quartz Creek. These grid cells are relatively homogeneous and representative of broad areas of tundra in the Quartz Creek area. The centers of the cells are marked with a white "X" visible from the air, and florescent pin flags. The GPS coordinates of the centers were determined with a Garmin GPS unit that averaged the values for 2 minutes.

Q-1, N65˚27.109', W164˚37.662'. Moist Eriophorum vaginatum, Betula nana Graminoid, Dwarf-shrub Tundra. (Typical tussock tundra)

Q-2, N65˚27.218, W164˚38.184'. Nonsorted stripes with lichen-rich tundra. Stripes: Dry Cladonia spp, Empetrum hermaphroditum, Vaccinium uliginosum Lichen, Prostrate Dwarf-shrub tundra.

Interstripe areas: Moist Betula nana, Carex bigelowii Dwarf-shrub, Graminoid Tundra. (This site is near Larry's met station.)

Q-3, N65˚27.256', W164˚37.935'. Moist Salix planifolia ssp. pulchra, Calamagrostis canadensis Tall Shrubland. (shrub tundra at head of Mauze Gulch drainage).

The purpose of the Atqasuk and Barrow ATLAS grids is to characterize zonal inland and coastal vegetation for the Flux study in a form that is comparable to the other Flux grids and complement long-term information from Webber and others at these sites.

This is a 100 x 100-m grid in zonal tussock-tundra vegetation. The Atqasuk grid was characterized in 1998. During our 1999 visit, LAI was measured at 33 random grid points and biomass clip harvest was collected at 10 random points. Both LAI and biomass were done using the same methods as at Ivotuk. Thaw was measured using the CALM protocol. The vegetation had not greened up completely so the site was revisited on July 15 to record peak-season LAI.

Point sampling of plant species, vegetation height, moss layer thickness, soil organic layer thickness, vegetation types, LAI, biomass, and plant community composition was done using the same methods as at the other ATLAS grids (see 1998 Field report). The vegetation had not greened up yet, so the site was revisited July 18 to record peak-season LAI.

The purpose of these grids are to characterize acidic and non-acidic tundra at the major vegetation transition at the northern edge of the Arctic Foothills. These two grids provide a good replicate for information collected at the Sagwon Hills for the Flux Study, and good intermediate sites along the Barrow-Ivotuk climate gradient. The Ivotuk camp provided helicopter and communication support. We camped for 6 days along the Oumalik River at the boundary between acidic tundra and non-acidic tundra. Acidic tundra occurs on upland surfaces, and non-acidic tundra occurs on the lowland loess deposits downwind of the sand sea that covers most of the coastal plain between the Colville and Meade Rivers. Sampling was done during a spectacular display of Eriophorum vaginatum flowering in the Arctic Foothills. A similar event was seen in 1982.

The grids are 50 x 50 m with 5-m grid-point spacing and are marked with panels for aerial photography. Air and ground temperature recording stations were established for Vladimir Romanovsky. Chein-lu Ping's group characterized soils during a visit on July 10. The coordinates of the centers of the grids are O-1 (Oumalik non-acidic site): N69∞44.12', W155∞52.17', and O-2 (Oumalik acidic site): N69∞43.95', W155∞51.78'.

Vegetation, biomass and LAI were sampled using the same methods as at the other ATLAS grids with the exception that no point sampling of species at the grid points was done due to time constraints.

The sites are on the approximate boundary between MNT and MAT tundra. The MNT site is on a small, lower north-facing slope. The calcareous soils have loess parent material that was derived from the sand sea to the north of the site. The acidic MAT soils are the result of peat deposition on top of the loess. Peat accumulation is deeper on the less steep upper hillslopes. There is a fairly sharp boundary dividing MNT and MAT that is evident on many hill slopes in the region at about 200-foot elevation. The slope at the MNT site (O-1) is not long enough to put in a 100m grid so we put in a 50 m grid. The site is otherwise excellent and offers well developed MNT and MAT tundra in close proximity to each other and close to water for the camp.

Frost scars affect about 50-60% of the site, but nearly all of these are well vegetated and appear stable. They are detectable by the lack of Tomentypnum nitens or a thick moss carpet. Thaw is highly variable. On 7 July, thaw averaged about 35-40 cm on frost scars and about 15-25 cm in inter-scar areas. Lupinus arcticus was flowering abundantly at time of sampling. There are abundant low shrubs of Salix glauca 25-30cm tall. Similar sites occur all along the Oumalik River on hill slopes and ridge crests, particularly north of this site.

The MAT site is about 0.5 km south of the O-1 on an ecotone between MNT and shrubby MAT. The site is a good representative of MAT, but it has occasional MNT species (e.g. Tomentypnum nitens, Dryas integrifolia, Senecio atropurpureus, Saussurea angustifolium) especially on frost scars. To the south the tundra becomes somewhat shrubbier. To the north the tundra has many more MNT species. Thaw at the acidic site was very shallow, averaging about 14 cm in the intertussock areas, about 25 cm on the tussocks, and 35 cm on frost scars. Frost scars are much less common (7 of 121 points) than at the MNT site (36 of 121 points).

A land cover map of the Arctic Slope was prepared in 1998 by extrapolation of the Kuparuk River map to all of northern Alaska, using a mosaic of 23 Landsat-MSS images (Fig. 2, Muller et al., in press). In 1999, we assessed the accuracy of the map by examining the vegetation at 240 random points along six transects, mainly in the western part of the map, where we previously had very little ground information. We used the same methods for accuracy assessment as in the 1996 assessment of the Kuparuk River basin land-cover map (Muller et al., 1998) except the transects were chosen to take maximum advantage of available fuel. An Air Logisitcs Long Ranger helicopter was used for the assessment. Fuel caches were established at Liberator Ridge and the Ketik River to allow access to the western part of the map in the vicinity of Meat Mountain. Accuracy varied from about 65% on the Atqasuk to Meat Mountain transect to about 92% on the Ivotuk to Inigok transect (Fig. 3). A full report of the assessment is in preparation (Muller et al., in prep.)

Scientists involved in the Circumpolar Arctic Vegetation Mapping (CAVM) project and students in a university field course conducted an 1800 mile north-south transect in the Canadian Arctic in order to investigate large-scale variation in vegetation. Our objectives were to help define phytogeographic zonation related to climate. Three goals of the project were to: (1) resolve interpretations of Arctic vegetation zonation (i.e. the Russian, Fennoscandian, and North American schools of thought) in order to develop a uniform and internationally accepted terminology for subdividing Arctic vegetation, (2) develop better understanding of vegetation patterns in the Canadian Arctic by bringing the principals involved in the CAVM to the least well-documented of the circumpolar regions, and (3) promote interest and research in the Arctic by involving graduate and undergraduate students in the project through the University of Minnesota field course, Arctic Field Ecology.

Participants included:

CAVM scientists and their areas of expertise (in parentheses):

Dr. Fred Daniëls, Germany (Greenland)

Dr. Sylvia Edlund, Canada, (High Arctic Canada)

Dr. Arve Elvebakk, Norway (Svalbard)

Dr. Bill Gould, USA (Canada)

Dr. Nadezhda Matveeva, Russia (Taimyr Peninsula)

Dr. Skip Walker, USA (Alaska)

Dr. Boris Yurtsev, Russia (Russia)

Arctic Field Ecology students:

Dianna Alsup, graduate student, Texas A & M University

April Desjarlais, undergraduate student, University of Saskatchewan

Christine Hill, graduate student, Northeastern Illinois University

Howard Hill, graduate student, Northeastern Illinois University

Chris Schadt, graduate student, University of Colorado

We visited 11 sites by twin otter and helicopter along the transect (Fig. 4):

- Eureka and East Wind Lake on Ellesmere Island,

- Bundy Fiord, Expedition Fiord, and Cape Levvel on Axel Heiberg Island,

- Stratigrapher River on Amund Ringnes Island,

- A low altitude flight (50-100 feet) from Eureka to Resolute, passing over

Amund Ringnes Island, Cornwall Island and Bathurst Island,

- Resolute on Cornwallis Island,

- Cambridge Bay, Tuktu River, and Hadley Bay on Victoria Island, and

- Daring Lake near the northern limit of trees.

At each site we: (1) conducted floristic surveys and (2) sampled plant communities along a toposequence in order to describe the range of representative vegetation and soils in wet, mesic, dry, riparian and snowbed environments. We conducted about 75 relevés along the transect.

We compared our observations along the transect with current zonal definitions and are working toward an international consensus on circumpolar arctic vegetation zonation related to climate. Preliminary observations indicate that the zonation patterns are complex in the Canadian Arctic because of the mix of large and small islands, frozen and open ocean, and strong variation in substrates. Nevertheless, a clear gradient was observed related to climate and comparable to patterns seen in other Arctic regions. There is a dominance by tall and low shrubs in the southern portions of the Arctic (e.g., Daring Lake), which give way to dominance by erect dwarf shrubs (e.g., southern Victoria Island), and then to prostrate dwarf shrubs in the mid Arctic regions (e.g., Resolute, Eureka, Bundy Fiord, Expedition Fiord, northern Victoria Island). Woody plants disappear entirely in the coldest areas (e.g., Amund Ringnes Island). Trends in other plant functional types and Braun-Blanquet syntaxonomical units were also noted and summarized in table format. Distinct plant-community differences related to parent material were also observed. Most of the transect was in calcareous limestone and dolomite regions.The expedition members recommended another transect along an acidic gradient, possibly on Baffin Island and Ellesmere Island or Greenland in summer 2000. A data report containing field information from each site and a publication describing the transect results are in preparation.

Skip Walker

Note new address after June 1!

Institute of Arctic Biology

University of Alaska Fairbanks

311 Irving I

PO Box 757000

Fairbanks, Alaska 99775-7000

ffdaw@uaf.edu