Tundra Research Articles

Phosphatase enzyme activity at subzero temperatures in arctic tundra soils

Etude de l'activite phosphomonoesterasique dans des sols organiques associes a Eriophorum vaginatum preleves a Eagle Creek (65°10'N, Alaska)

Nitrogen cycling in Arctic lakes and ponds

Nitrogen cycle studies were carried out on two distinct systems in arctic Alaska. Research on the first, a series of small tundra thaw ponds near Barrow, was carried out as part of the International Biological Program Tundra Biome program. Research on the contrasting system, Toolik Lake, was done during the year following completion of the Barrow pond research. Toolik Lake is located on the north flank of the Brooks Range, approximately 130 km south of the Beaufort Sea coast.

Крупномасштабное картографирование как метод детального изучения структуры растительного покрова (на примере арктической тундры о-ва Врангеля)

Крупномасштабное картографирование как метод детального изучения структуры растительного покрова (на примере арктической тундры о-ва Врангеля)

The summer radiation and heat budget of the Arctic and Antarctic

For two pairs of arctic and antarctic stations, one coastal and one mountainous, an intercomparison between the summer radiation and surface energy budgets was carried out. The station pairs were similar in both latitude and altitude. It was found that the global radiation was larger for both antarctic stations. This is the result of a smaller Earth-Sun distance and cleaner atmosphere in Antarctica. Cloudiness, and for the arctic mountainous station substantial screening of the sun, also contributed. Further, large differences were found in the albedo. In the Arctic, the summer surfaces considered were bare tundra and melting snow, with respective albedos of 20 and 59%, while in Antarctica the surfaces considered were melting and dry snow, with albedos of 67 and 83% respectively.

North American terrestrial vegetation

Contributors Preface to the first edition Preface to the second edition 1. Arctic tundra and polar desert biome Lawrence C. Bliss 2. The taiga and boreal forest Deborah L. Elliot-Fisk 3. Forests and meadows of the Rocky Mountains Robert K. Peet 4. Pacific northwest forests Jerry F. Franklin and Charles B. Halpern 5. California upland forests and woodlands Michael G. Barbour and Richard A. Minnich 6. Chaparral Jon E. Keeley 7. Intermountain valleys and lower mountain slopes Neil E. West and James A. Young 8. Warm deserts James A. MacMahon 9. Grasslands Phillip L. Sims and Paul G. Risser 10. Eastern deciduous forests Hazel R. Delcourt and Paul A. Delcourt 11. Vegetation of the southeastern coastal plain Norman L. Christensen 12. Freshwater wetlands Curtis J. Richardson 13. Saltmarshes and mangroves Irving A. Mendelssohn and Karen L. McKee 14. Alpine vegetation William Dwight Billings 15. Mexican temperate vegetation Alejandro Velazquez, Victor Manuel Toledo and Isolda Luna 16. The Caribbean Ariel E. Lugo, Julio Figueroa Colon and Frederick N. Scatena 17. Tropical and subtropical vegetation of Mesoamerica Gary S. Hartshorn 18. Vegetation of the Hawaiian Islands Lloyd L. Loope Subject index Species index.

Changes in Tundra Vegetation of Taymyr Peninsula under Man‘s Impact )

At present time the tundra biome is one of the least changed by man. It is a good model for studying of new type of communities formation that is taking place for the first time during the whole period of existence of the tundra biota. There are many local ways of the vegetation cover restoration, but general tendency for the whole tundra zone can be traced. The restoration of disturbed cover takes place by means of the native flora. Anthropochorous species are not of great significance in these processes. About 40 species in every region, that are naturally typical of eroded and zoogenic habitats, are active in the plant cover restoration. The most typical way of succession is the meadows formation which are more productive than natural tundra communities and they are rather stable with their composition and structure being fixed for long period after man‘s impact has ceased. The meadow anthropogenic stage in the tundra zone is analogous to that in the temperate belts after removal of forest, but it is even more stable and prolonged. If natural vegetation has not been disturbed completely, some grasses become more abundant, but do not form any dense cover. In this case the natural cover will be restored in a relatively short time. There are very few types of anthropogenic communities in the tundra and those few are drastically poor in floristic composition. In high arctic latitudes the human activities lead to a sharp reduction of biota diversity which is already poor there.

Nitrogen cycling in arctic lakes and ponds

Nitrogen cycle studies were carried out on two distinct systems in arctic Alaska. Research on the first, a series of small tundra thaw ponds near Barrow, was carried out as part of the International Biological Program Tundra Biome program. Research on the contrasting system, Toolik Lake, was done during the year following completion of the Barrow pond research. Toolik Lake is located on the north flank of the Brooks Range, approximately 130 km south of the Beaufort Sea coast.

We Are Americans Now, We Live in the Tundra

We Are Americans Now, We Live in the Tundra

Alpine Tundra Soil Bacterial Responses to Increased Soil Loading Rates of Acid Precipitation, Nitrate, and Sulfate, Front Range, Colorado, U.S.A.

To determine if the soil bacterial community exhibited a response to perturbations from acid rain, the effects of increased soil loading rates of acid precipitation, nitrate, and sulfate on the alp...

Paleoenvironmental Interpretations of Holocene Insect Fossil Assemblages from Four High-Altitude Sites in the Front Range, Colorado, U.S.A.

A series of four Holocene age sites in the Front Range, Colorado, forms an altitudinal transect from subalpine forest to alpine tundra in the modern environment. Insect fossil assemblages from thes...

Composition, form, and distribution of the forest-alpine tundra ecotone, Indian Peaks , Colorado, USA

Zusammenfassung: Zusammensetzung, Form und Verbreitung des Ubergangssaumes zwischen der Waldstufe und der alpinen Tundrastufe im Indian Peaks Gebiet, Front Range, Colorado, USA Die aufiergewohnlich starke touristische Beanspruchung des Indian Peaks Gebietes (Colorado) hat zur Degradation aller Oko systeme gefuhrt, wobei insbesondere die Pflanzengesellschaften des Ubergangssaumes (Okotons) zwischen der oberen Waldstufe und der alpinen Tundrastufe schwere Schadigungen erfuhren. Als Grundlagenstudie fur eine Uberwachung zukiinftiger Schaden werden die gegenwartige Form, Zusammensetzung und Verbrei tung der Baumarten innerhalb des Okotons untersucht. Im Hohen bereich von unterhalb der Waldgrenze bis zur Obergrenze der Baumarten konnen fiinf vorherrschende Wuchsformen der Baume unterschieden werden. Drei Baumarten dominieren innerhalb des Okotons, daneben sind drei weitere Arten von nachgeordneter Be deutung vertreten. Die raumliche Verbreitung des Okotons zeigt mancherlei Abwandlungen aufgrund mikroklimatischer und topo graphischer Unterschiede, geomorphologischer Einfliisse sowie im Gefolge anthropogener Einwirkungen.

Dinitrogen Fixation in Alpine Tundra, Niwot Ridge, Front Range, Colorado, U.S.A.

The process of dinitrogen fixation was studied in the alpine tundra ecosystem at Niwot Ridge, Colorado. In situ fixation activities were measured by the acetylene reduction method in the soils of t...

Comparative Study of Metabolic Activities of Bacteria in Three Ecoregions of the Colorado Front Range, U.S.A.

A comparative study of the bacteria occurring in soils of montane grasslands, montane forests, subalpine forests, and alpine tundra habitats was conducted to ascertain the types of bacterial metabo...

Going High: The Story of Man and Altitude, High Altitude Physiology Study: Collected Papers, Submarine Permafrost on the Alaskan Continental Shelf, Arctic Animal Ecology, Biology and Quaternary Environments. Based on the Symposium on Biological Problems in the Reconstruction of Quaternary Terrestrial Environments, Held in Canberra, February 1978, Limnology of Tundra Ponds, an Arctic Ecosystem: The Coastal Tundra at Barrow, Alaska

Going High: The Story of Man and Altitude, High Altitude Physiology Study: Collected Papers, Submarine Permafrost on the Alaskan Continental Shelf, Arctic Animal Ecology, Biology and Quaternary Environments. Based on the Symposium on Biological Problems in the Reconstruction of Quaternary Terrestrial Environments, Held in Canberra, February 1978, Limnology of Tundra Ponds, an Arctic Ecosystem: The Coastal Tundra at Barrow, Alaska

Tundra to Desert: a Contrast in Biomes

Tundra to Desert: a Contrast in Biomes

Human Adaptation to Arctic Zones

The study of human adaptation to polar areas has engaged scholars in many fields since the late nineteenth century. The first two scientific monographs on the Eskimo were published in 1888 (16,55), and were soon followed by useful reports (2, 39, 99, 110). Since then much work has been undertaken, and efforts at a synthesis are now under way. Tundra ecosystems were recently a focus of research efforts by the International Biological Program (IBP), and students with interest in the human ecology of this region now have a rich and rapidly growing literature. The Swedish component of the IBP !Tundra Biome has published a useful collection of papers on the structure and function of tundra ecosystems (102). Hildes,(53) and Laughlin (75) summarized knowledge of arctic human ecology, and the synthesis volume from the human adaptability component of the US/lBP (66) updates and fills in many of the gaps identified earlier by Hildes (53) and Laughlin (75). The annotated bibliography by Culver (30) is outdated but still useful. Important discussions on the methodology of studying human adaptability to cold stress are presented by Yoshimura & Weiner (119) and Weiner & Louri (117). Important surveys of human adaptation to cold are those by Folk (42), Carlson & Hsieh (29), Edholm & Lewis (38), Van Wie (113), and Little & Hochner (81). The latter ap­ proaches the problem of thermal stress with an emphasis on growth and development. The best recent syntheses of tundra ecology are by Bliss et al (15) and Brown et al (17a). In this review I shall concentrate on human social and cultural adaptive strategies as they are applied to High Arctic populations. At appropriate places the reader will be referred to relevant biological adaptations treated

Geobotanical Areas of Both Polar Tundras The Arctic and Antarctic: Their Division into Geobotanical Areas V. D. Alexandrova

Geobotanical Areas of Both Polar Tundras The Arctic and Antarctic: Their Division into Geobotanical Areas V. D. Alexandrova

Registration of Tundra Bluegrass1 (Reg. No. 19)

Registration of Tundra Bluegrass¹ (Reg. No. 19)

In Vitro and Nylon-Bag Digestibilities of Reindeer and Caribou Forages

In Vitro and Nylon-Bag Digestibilities of Reindeer and Caribou Forages

Terrestrial Protozoa*

SYNOPSIS Litters and soils are special interstitial ecosystems containing water in surface films and pore spaces, large amounts of organic matter, and are subject to extreme moisture and temperature fluctuations. “Terrestrial protozoa” are ubiquitous limnetic species tolerant of high CO2 tensions and possessing efficient encystment mechanisms.Protozoa exploit tiny microhabitats unavailable to larger animals (e.g. nematodes). Naked amebae dominate due to their flexible bodies and interface locomotion. Small flagellates may be abundant, especially in litters. Ciliates are less numerous but their species composition indicates the degree of moisture of the habitat, as do the slower‐growing testacea which become prominent in regions of slow decomposition (conifer and tundra biomes). Protozoa promote decomposition by enhancing bacterial metabolism, eating excess bacteria, and excreting simple compounds returnable to plants. Large populations, especially amebae, exploit the abundant bacterial flora of plant root zones (rhizosphere). One protozoon, Colpoda cucullus, has successfully invaded the surfaces of vegetation.