Toolik Lake

Toolik Lake

Author: James J. O'Brien

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 264

ISBN-13: 9401127204

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The limnological study of Toolik Lake began in the Summer of 1975. This research was an outgrowth of the arctic IBP project which had focused mainly on small Arctic pond ecosystems on the Alaskan Arctic coastal plain. It was thought desirable to study larger, deeper lakes which contained fish to further generalizations developed during the IBP study. Initial research on Toolik Lake and the surrounding lakes and ponds focused on process studies such as annual primary productivity of the lake or the vertical migration patterns of the resident zooplankton. In 1983 the philosophy of the research changed with the funding of a more integrated programme. The fundamental question posed was whether Arctic lake and stream ecosystems are regulated from the bottom up by nutrient availability or from the top down by the density and activity of top predators. In 1987 the Toolik Lake area was designated an LTER (Long-Term Ecological Research) site, one of 18 such sites throughout the United States, Puerto Rico and the Antarctic. The research theme for the Arctic LTER also focuses on the regulation of Arctic ecosystems, whether regulation comes from the top down or bottom up. The Arctic LTER also incorporates a terrestrial component as well as a lake and stream component.


Meddelelser Om Gronland

Meddelelser Om Gronland

Author: Bent Fredskild

Publisher: Museum Tusculanum Press

Published: 1996-12

Total Pages: 164

ISBN-13: 9788763512350

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Phytogeographically and climatically West Greenland includes parts of the low arctic and high arctic areas. The present vegetation and a summary of its history since the last glaciation based on pollen and macrofossil analyses are briefly described. The determination of more than 55,000 herbarium sheets of native phanerogams has been checked. Before preparing the dot maps it was necessary to decide at which level taxonomically difficult genera (eg: Antennaria, Draba, Poa, Puccinellia, and Stellaria would be treated). For all of these the criteria used are given. Dot maps have been prepared for 379 taxa. These maps have been grouped into 11 West Greenland distribution types, which clearly correlate with T W Böcher's biological distribution types (Böcher 1963). The collecting intensity in the large area is rather uneven. This is illustrated by a map giving the number of collections at the 305 localities from which 50 or more collections are at hand. Another map giving the number of taxa at 29 well-investigated localities illustrates the species diversity in the region. Most low arctic localities have more than 130 taxa, with 215 at the richest locality (Godhavn / Qeqertarsuaq on Disko), while the number at no high arctic locality exceeds lS0. Reference to the corresponding numbers in other parts of Greenland is given. Based on the dot maps a new delimitation of West Greenland in floristic provinces and districts is presented. It differs somewhat from that in Grønlands Flora / The Flora of Greenland (Böcher et al. 1957, and later editions). The major alteration is that the boundary between the low and high arctic phytogeographic provinces is now placed through north Disko - Nuussuaq. As a consequence of this the southernmost district in the high arctic is divided into an outer (NWso) and an inner province (NWsi). Minor alterations are suggested in the southern part of West Greenland.


Proceedings

Proceedings

Author: International Association of Theoretical and Applied Limnology

Publisher:

Published: 1988

Total Pages: 640

ISBN-13:

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Polar Lakes and Rivers

Polar Lakes and Rivers

Author: Warwick F. Vincent

Publisher: OUP Oxford

Published: 2008-09-11

Total Pages: 352

ISBN-13: 0191550183

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This is the first book to describe the ecology of high latitude lakes, rivers and glacial environments in both the North and South polar regions. From the lake-rich floodplains of the Arctic to the deep, enigmatic waters of Lake Vostok, Antarctica, these regions contain some of the most extraordinary aquatic ecosystems on Earth. They provide a fascinating diversity of habitats for plant, animal and microbial communities, and are proving to be valuable model systems for exploring many ecological themes including landscape-lake interactions, adaptation of life to environmental extremes, and controls on the structure and functioning of aquatic ecosystems. Some of these waters also have direct global implications, including permafrost thaw lakes as sources of greenhouse gases, subglacial aquatic environments as a storehouse of ancient microbes, and Arctic rivers as major inputs of freshwater and organic carbon to the World Ocean. Given that many polar areas are experiencing greater climate warming than at lower latitudes, these ecosystems can also be viewed as sentinels of global change. This timely volume brings together many of the world's leading researchers in polar limnology to describe these diverse aquatic environments and their ecology. It introduces each major ecosystem type, examines the similarities and differences between Arctic and Antarctic systems as well as their responses to environmental change, and describes new frontiers for future research. A glossary of terms is provided for non-specialists, and a set of colour plates introduces the ecosystems and their biota. Polar Lakes and Rivers will be of value to students and specialist researchers alike, as well as to those with a more general interest in aquatic ecology, polar environments or global change who require an authoritative overview of this fast emerging topic.


Ostracoda as Proxies for Quaternary Climate Change

Ostracoda as Proxies for Quaternary Climate Change

Author:

Publisher: Newnes

Published: 2012-12-31

Total Pages: 379

ISBN-13: 044453637X

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Ostracod crustaceans, common microfossils in marine and freshwater sedimentary records, supply evidence of past climatic conditions via indicator species, transfer function and mutual climatic range approaches as well as the trace element and stable isotope geochemistry of their shells. As methods of using ostracods as Quaternary palaeoclimate proxies have developed, so too has a critical awareness of their complexities, potential and limitations. This book combines up-to-date reviews (covering previous work and summarising the state of the art) with presentations of new, cutting-edge science (data and interpretations as well as methodological developments) to form a major reference work that will constitute a durable bench-mark in the science of Ostracoda and Quaternary climate change. - In-depth and focused treatment of palaeoclimate applications - Provides durable benchmark and guide for all future work on ostracods - Presents new, cutting-edge science