Seed Germination in Arctic and Alpine Species

Account of germination tests made with the aim of ascertaining seed viability of plants from the arctic tundra of Alaska (near Umiat, 69 22 N, 152 10 W) and the alpine tundra of Wyoming. A greater proportion of the latter germinated (of 26 species, 21 i.e. 80%; of 36 arctic species, 22 or 61%); though individual species from both tundras showed a high percentage of germination. Conditions affecting germination, influence of light and darkness, wetness, etc., are analyzed

IBP High Arctic Ecosystem Study, Devon Island

The research in 1971 continued to emphasize the physical environment and the biological response of organisms on meadows (c. 49 per cent of the lowland) and raised beach ridges (c. 15 percent of the lowland) in the Truelove Lowland. The lakes (22 percent) were not included in the studies and all data are expressed on the basis of a 3,300 ha land area. As in 1970, the research was concentrated on a typical mesic meadow (soils, meteorology, primary production, nitrogen fixation, invertebrates, decomposition) with additional data gathered in 2 to 5 other meadows (extensive sites), depending upon the research unit. The intensive beach ridge site, approximately 7,500 years old, was studied with the same components of research as the master meadow site. In addition, 2 to 11 other beach ridges (extensive sites), and a site on the plateau (c. 300 m. above sea level) were studied in varying detail (soils, meteorology, primary production, and invertebrates). In all, 22 separate research projects were conducted in 1971. Two flights for aerial photography of the Truelove Lowland were made. The Atmospheric Environmental Service of the Department of Transport photographed black and white and an infrared scan in late July, and the Inland Waters Branch photographed black and white imagery at 3,330 and 830 m and infrared false colour at 1,660 m in mid-August. ..

Devon Island Programs, 1970

The Arctic Institute's research base on Devon Island was used by over twenty-five investigators and their field assistants during the 1970 summer field season, from late April to mid-September. There were two separately directed, but related, programs. One, a large integrated ecosystem study, was directed by L.C. Bliss of the University of Alberta and sponsored by the Canadian International Biological Program (IBP); the other was an Arctic Institute-sponsored comparative ecology project, under the direction of James A. Teeri. Substantial improvements were made to the Base Camp (located in the Truelove Lowland), and a total of 8 Parkall and Jamesway huts are now available as sleeping quarters, laboratories, warehouse, kitchen, and storage areas. In addition, a separate field camp was established about 8 km east of the base to facilitate the study of muskox, fox, and weasel. Local transportation was by two skidoo motorboggans, a double-tracked Ranger V vehicle and trailer, and a Massey-Ferguson tractor and trailer. Transportation between Resolute and the Base Camp was by Otter and Beaver aircraft. ..

Adaptations of Arctic and Alpine Plants to Environmental Conditions

Discusses tundra environments, i.e. beyond the climatic timberline, mostly in Alaska, Canada, Greenland, and USSR, and various mechanisms used by plants in adapting to them. Despite a very short growing season with low air and soil temperatures, adverse wind effects, and a low nitrogen-utilization level, tundra plants are well adapted to their environment. They are apparently efficient converters of energy, due partly to their utilization of much of the growing season for growth and development, their use of considerable carbohydrate reserves of the previous year, and the higher caloric values of the species

Susceptibility to Environmental Impact in the Queen Elizabeth Islands

Exploration for oil and gas is proceeding on a rapidly increasing scale in the Queen Elizabeth Islands, and the region needs therefore to be assessed comprehensively in terms of susceptibility of habitat to physical disturbance. ... The evaluation is however necessarily provisional, since only a small part of the total land area has so far been the subject of detailed biological description. Areas likely to be ecologically critical are delimited with the object of assisting governmental and industrial planning. ... Land areas were subdivided into four broad categories based largely on observations made by the present authors. ... The categories are as follows: 1) Polar Desert (31% of land area): susceptibility low .... 2) Polar Semi-desert (25% of land area): susceptibility moderate .... 3) Diverse terrain (22% of land area): susceptibility high in many sites. ... 4) Large meadows (<2% of land area): susceptibility high .... While biological diversity and plant cover are far less in the High Arctic than in the warmer mainland Arctic, there are numerous areas where the land is susceptible to disturbance. The most common forms of degradation are sheet and gully erosion in areas of sparse plant cover, and the softening in summer of slightly disturbed surfaces on moist, fine-grained substrates. This situation contrasts with that in the Low Arctic where removal of vegetation and potential thermokarst are of great concern. In relatively small areas of high plant cover, surfaces have a susceptibility similar to the extensive tundra areas farther south. The biological consequences of disturbance can be much greater, however, not because of deleterious effects on the landscape alone, but because these isolated rich sites comprise the bulk of the energy base for the remainder of the terrestrial food web

Adaptations of Luzula confusa to the Polar Semi-Desert Environment

Luzula confusa is both morphologically and physiologically adapted to the polar semi-desert environment of the western Queen Elizabeth Islands. This species combines the more efficient graminoid photosynthetic system and a less drought-resistant mechanism with some of the cushion plant energy-trapping characteristics such as tufted growth form and persistence of dead leaves, with consequent thicker boundary layer. In this manner, the plant is able to assimilate carbon throughout the 24-hr arctic day. The species utilizes the most favorable part of the growing season by rapid initiation of growth via relatively high photosynthetic rates, especially at low temperatures. This species is very responsive (net assimilation rates) to small changes in leaf temperature and leaf water potential. This permits the species to take advantage of small rises in leaf temperature (leaves normally 5 to 8 degrees C) and to adjust to high VPD and low leaf water potential during the occasional drought. The slow-growing, long-living conservative strategy of this species appears ideally suited to areas that are limited in their vascular plant cover because of rigorous environments. Within the range of habitats available, Luzula confusa predominates in sites of intermediate moisture with abundant cryptogams. It does not occur in the polar deserts with their drier surface soils except in snowflush communities.Key words: Luzula confusa, High Arctic, plant/water relations, net photosynthesis, plant phenology, polar semi-desertsMots clés: Luzula confusa, nord de l'Arctique, relations plantes-eau, photosynthèse nette, phénologie des plantes, semi-déserts polaire

Overwinter Phenology of Plants in a Polar Semi-desert

Arctic and temperate-latitude tundra plants must make efficient use of the growing season, because it is very short. A variety of leaf-development strategies permit growth in the cool summers. ... Winter phenology was observed under field conditions for 27 of 33 angiosperm species found on King Christian Island. ... The full significance of overwintering leaf condition and the variability of this pattern within the High Arctic needs further investigation

Origin and Significance of Wet Spots on Scraped Surfaces in the High Arctic

In the western Queen Elizabeth Islands, Northwest Territories, where most of the petroleum exploration in the High Arctic is being conducted, much of the low lying land is covered with sorted and non-sorted circles and polygons 0.5-2.0 m in diameter. ... Much of the oil-camp construction takes place on the coastal low-lands on polygonal surfaces composed of sandy to silty loams. When these surfaces are scraped and reworked for camp areas and air strips in summer, it is common for them to have numerous wet spots which become soft and spongy and of jelly-like consistency when equipment is moved across them .... a small study was conducted in 1972 at the Sunoco Camp no. 3002 on the northeast side of King Christian Island (77° 44'N, 101° 15'W), approximately 3.5 km from the sea. There the surface soils consist of fine marine sediments intermixed with small pebbles. The entire camp area and the Hercules landing strip are built on a surface covered with non-sorted polygons. ... Excavations were made on both the disturbed surface, where the damp spots occurred, as well as in the undisturbed area adjacent to the camp. ... From the information obtained during the excavations in each of the areas described, it is possible to understand more clearly the mechanisms responsible for the features. The wet spots in the cleared work-area are located at the foci of ground-ice accumulations which occur at the margins and intersections of the non-sorted patterned ground. The occurrence of ground-ice at the perimeters of the non-sorted polygons is explained by the contraction cracks which form and outline the patterned ground. Moisture from the scanty precipitation (especially blowing snow) accumulates in the cracks and eventually becomes incorporated in the underlying frozen ground as ice veins. Since the cracks are areas of greater moisture (as well as microhabitats), the plants tend to congregate in them and in turn reinforce the moisture content by (1) their greater moisture-holding capacity, (2) more efficient moisture entrapment, and (3) retarding the rate of thaw owing to the slightly greater insulation they provide. Once such a surface is disturbed, as it was in this case by light blading with a bulldozer, the vegetation is destroyed (at least the above- surface parts). Greater thawing may then occur, during which the moisture is drawn to the surface by capillary action as melting of the ground ice takes place. These bladed areas increase soil compaction and therefore thermal conductivity, and so melt is accelerated. In addition, the organic matter and remaining live plant material in the crack act as a "wick" drawing the moisture to the surface. A last but very important factor is the movement of heavy equipment over the surface. ... Their main area of concentration was in the work area in front of the camp where there was continual movement of equipment. The repetitive application of pressure over an area rich in ground ice ... has a "pumping" action whereby moisture is slowly forced to the surface. This constant agitation distributes the water throughout the mass, and the material becomes "quick" owing to the reduction of intergranular pore pressure. This results in loss of cohesion, and the material becomes spongy and jelly-like when pressure is applied. The practical significance of this brief investigation is that the wet spots will probably not increase in size or the surface deteriorate further, but in fact there should be an improvement. It appeared from discussion with camp managers on two islands that, after two or three summers of use of the surface and scraping, the wet spots dry out. The best approach to the use of these vegetated (and therefore ice-rich) non-sorted, patterned ground surfaces in the High Arctic is to clear the areas before thawing occurs in the spring, and if possible not to use them heavily during the first one or two summers. By the second or third summer much of the ground ice will have thawed, so there should be less chance of major problems with wet and soft spots - unless the summer is unusually wet, as it was 1973