... plant species, certain individual plants within species, and certain plant parts within individuals. This behavioural interaction between lemmings and their food-plants has therefore the potential to influence both species’ composition ...
... to test ecological and evolutionary predictions on the oviposition behaviour of sawflies to study the role of natural enemies in regulating populations of sawflies and lepidopterans. Willows as archives on climate and herbivores At all ...
... considerably longer one when only perennial living plants and dead plant material are available as forage. This naturally becomes more extreme and demanding for the animals, the further north one goes. In the High Arctic regions vascular ...
... using isozyme and DNA techniques (RAPD) in collaboration with Hilde Nybom, Balsgård, Swedish University of Agricultural Sciences. Data analyses The data on ramet frequency, the chemical composition of different ramet categories and plant ...
... for centuries. It is one of the most important questions that were given a theoretical framework in the theory of natural selection by Darwin and Wallace. Yet, however, much remains to be discovered before we know whether the distribution of ...
... our understanding of community mechanisms in general, and provide valuable information for the management of natural resources in the Arctic. Important forage plants for herbivores are to be found among all major life forms of tundra ...
... of the project is being carried out in collaboration between Anders Dahlberg at the Swedish University of Agricultural Science in Uppsala and Monique Gardes and Jean-Yves Charcosset at the Université Paul Sabatier in Toulouse, France. The ...
... land and connected Northeast Asia and North America during much of the glaciations. A similar interpretation is natural for the American counterpart. Dates June–September 1999 Participants Principal investigator Reidar Elven Botanical ...
... C. (1989). The latitudinal gradient in geographical range: how so many species coexist in the tropics. American Naturalist 133, 240-256. Young, S. B. (1971). The vaseular flora of St. Lawrence Island with special reference to floristic ...
... studies (Nikolai Smirnov). Skins were taken by Anders Hansson and Peter Mortensen for the Swedish Museum of Natural History. Chromosome preparations were made on board from 104 collared lemmings, 11 brown lemmings and 19 root voles. ...
... show directions and rates at which springtails recolonized the Arctic after the last glaciations? With behavioural assays of dispersal rates we can estimate the rate at which a population would move in to and colonize an area. By using ...
... element of local population differentiation and disruptive variation patterns in some of the areas. Samples of natural populations of Alaskan wheatgrass have previously been collected from Greenland, Iceland, Scandinavia and Siberia, and ...
... Principal investigator Anders Dahlberg Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences Uppsala, Sweden Principal investigator Vadim B. Fedorov Department of Biology, University of Oslo Norway ...
... of Animal Ecology, Lund University Sweden Principal investigator Gudmundur A. Gudmundsson Icelandic Institute of Natural History Reykjavik, Iceland Martin Green Department of Animal Ecology, Lund University Sweden Anders Hedenström ...
... within the populations. Dates June–September 1999 Participants Principal investigator Noél Holmgren Department of Natural Sciences, Skövde University Sweden Principal investigator Liv Wennerberg Department of Animal Ecology, Lund University ...
... places great demands on the birds and we can expect them to have evolved a wide range of physiological and behavioural adaptations. Given the inaccessibility of most tundra areas and the necessity for relatively advanced techniques, ...
... at high geographic latitudes. The experiments were performed in manipulated magnetic field conditions under natural, clear and overcast skies and in the local geomagnetic field with clock-shifted birds. Methods At the end of the ...
... these difficulties. To do this we have studied the birds’ orientation behaviour in circular cages under as natural conditions as possible: under natural clear skies and when exposed to only the natural geomagnetic field. By comparing ...
... Research Den Burg, Texel, The Netherlands Principal investigator Gudmundur A. Gudmundsson Icelandic Institute of Natural History Reykjavik, Iceland Principal investigator Noél Holmgren Department of Natural Sciences, Skövde University Sweden ...
... in dissolved organic compounds, which are generally responsible for most of the absorption of UV-radiation in natural waters. Hence, damaging UV-radiation may penetrate to substantial depths. On the other hand, it is perhaps more common ...
