K. Danell (kjell.danell@szooek.slu.se) and]. P. Ball, Dept of Animal Ecology, Swedish Univ. of Ag... more K. Danell (kjell.danell@szooek.slu.se) and]. P. Ball, Dept of Animal Ecology, Swedish Univ. of Agricultural Sciences, SE-901 83 Urnea, Sweden. ?A. Hofgaard, Climate Impacts Research Centre (CIRC), Box 62, SE-981 07Abisko, Sweden, and Dept of Animal Ecology, Swedish Univ. of Agricultural Sciences, SE-901 83 Ume?, Sweden. -TV. Callaghan, Abisko Scientific Research Station, Box 62, SE-981 07 Abisko, Sweden, and Sheffield Centre for Artic Ecology, 26 Taptonville Road, Sheffield, U.K. S10 5BR.
Effects of herbivores and standing crop on plant species and functional trait composition in Beri... more Effects of herbivores and standing crop on plant species and functional trait composition in Beringia
Produced by the ICSU/WMO Joint Committee for IPY 2007–2008 By: Ian Allison and Michel Beland (Co-... more Produced by the ICSU/WMO Joint Committee for IPY 2007–2008 By: Ian Allison and Michel Beland (Co-Chairs), Keith Alverson, Robin Bell, David Carlson, Kjell Danell, Cynan Ellis-Evans, Eberhard Fahrbach, Edith Fanta, Yoshiyuki Fujii, Gisbert Gilbertson, Leah Goldfarb, Grete Hovelsrud-Broda, Johannes Huber, Vladimir Kotlyakov, Igor Krupnik, Jeronimo Lopez-Martinez, Tillmann Mohr, Dahe Qin, Volker Rachold, Chris Rapley, Odd Rogne, Eduard Sarukhanian, Colin Summerhayes, Cunde Xiao
The bite diameter selection by moose in relation to twig quality on four phenotypes of Scots pine... more The bite diameter selection by moose in relation to twig quality on four phenotypes of Scots pine was studied on the basis of a field cafeteria experiment. Comparison of twig quality was made among: 1) phenotypes, 2) different twig diameters, and 3) mean moose bite diameters. Chemical and morphological analyses of the trees indicated that twig fibre and tree/shoot size strongly affected moose bite diameter choice. Sight and chewing sensation are suggested to be the main browsing strategies used by moose. Moose adjusted the bite diameter among phenotypes on the criterion of similar food quality. The factors involved may play a multiple role in affecting moose foraging. Quantitative features of trees had no significant effects on moose bite diameter selection.
The muskrat Ondatra zibethicus is one of the semi‐aquatic rodents that has been introduced into m... more The muskrat Ondatra zibethicus is one of the semi‐aquatic rodents that has been introduced into many areas of the world. It is regarded as a most successful vertebrate invader. In northwestern Europe, it was introduced to Finland in 1919 and to the Kola Peninsula in 1931. From these areas, it spread ‘naturally’ to Sweden and Norway, respectively. Here the history of the introduction, dispersal, population development, impact on plant communities, impact on man, and indirect and direct effects on other animals in northwestern Europe are reviewed. The biological features of the muskrat are discussed in relation to the attributes of other vertebrates that are regarded as successful invaders.
A laser system and techniques which compensate for laser fluence drop off or losses of irradiatio... more A laser system and techniques which compensate for laser fluence drop off or losses of irradiation as an ablating laser beam is traversed on a curved surface (e.g., on corneal tissue). The disclosed ablating laser system and techniques compensate for fluence differentials from pulse-to-pulse by adjusting an appropriate parameter of a laser beam. In the preferred embodiment, the number of pulses imparted in the periphery, the size or shape of the ablating laser beam is adjusted with, e.g., a variable aperture placed in the beam delivery path, by changing a magnification of relay optics in the beam delivery path, or by increasing a number of ablation spots in peripheral portions of an ablation zone as compared with the number of ablation spots in a central portion of the ablation zone. The fluence is compensated for using empirically measured or theoretical fluence correction factors given the angle of the laser beam, size and shape of the ablation spot, etc. In addition to magnification adjustment, the present invention also employs the technique of changing the size of the aperture that is imaged o the eye to provide uniform energy density (i.e., fluence) throughout the entire area of the irradiation site. These techniques are used independently or in conjunction to reshape the curvature of the eye to correct myopia, hyperopia, astigmatism or combinations thereof.
Under the implementation of the Convention on Biological Diversity, a special emphasis has been p... more Under the implementation of the Convention on Biological Diversity, a special emphasis has been put on an integrated ecosystem approach. Some of the "Malawi principles" state that management objectives are a matter of societal choice, and that management should be decentralized to the lowest appropriate level. A key feature of the ecosystem approach includes conservation of ecosystem structure and function on a long term basis, while seeking an appropriate balance between conservation and use of biodiversity. The role of moose in the ecosystem and how the Malawi principles can be adopted in moose management were a focus of the 5th International Moose Symposium. All invited speakers and session chairs were asked to provide a brief summary of how they considered the Malawi principles to relate to the topic of their respective papers or sessions at the Symposium. Those summaries are given in this paper.
... John Pastor1 and Kjell Danell2 ... bouts to meet daily requirements of 5 – 10 kg per day (Bel... more ... John Pastor1 and Kjell Danell2 ... bouts to meet daily requirements of 5 – 10 kg per day (Belovsky and Jordan 1978, Renecker and Hudson 1986, Renecker and ... of leaves such that total leaf production during the growing season (removed leaves plus regrown leaves) did not differ ...
K. Danell (kjell.danell@szooek.slu.se) and]. P. Ball, Dept of Animal Ecology, Swedish Univ. of Ag... more K. Danell (kjell.danell@szooek.slu.se) and]. P. Ball, Dept of Animal Ecology, Swedish Univ. of Agricultural Sciences, SE-901 83 Urnea, Sweden. ?A. Hofgaard, Climate Impacts Research Centre (CIRC), Box 62, SE-981 07Abisko, Sweden, and Dept of Animal Ecology, Swedish Univ. of Agricultural Sciences, SE-901 83 Ume?, Sweden. -TV. Callaghan, Abisko Scientific Research Station, Box 62, SE-981 07 Abisko, Sweden, and Sheffield Centre for Artic Ecology, 26 Taptonville Road, Sheffield, U.K. S10 5BR.
Effects of herbivores and standing crop on plant species and functional trait composition in Beri... more Effects of herbivores and standing crop on plant species and functional trait composition in Beringia
Produced by the ICSU/WMO Joint Committee for IPY 2007–2008 By: Ian Allison and Michel Beland (Co-... more Produced by the ICSU/WMO Joint Committee for IPY 2007–2008 By: Ian Allison and Michel Beland (Co-Chairs), Keith Alverson, Robin Bell, David Carlson, Kjell Danell, Cynan Ellis-Evans, Eberhard Fahrbach, Edith Fanta, Yoshiyuki Fujii, Gisbert Gilbertson, Leah Goldfarb, Grete Hovelsrud-Broda, Johannes Huber, Vladimir Kotlyakov, Igor Krupnik, Jeronimo Lopez-Martinez, Tillmann Mohr, Dahe Qin, Volker Rachold, Chris Rapley, Odd Rogne, Eduard Sarukhanian, Colin Summerhayes, Cunde Xiao
The bite diameter selection by moose in relation to twig quality on four phenotypes of Scots pine... more The bite diameter selection by moose in relation to twig quality on four phenotypes of Scots pine was studied on the basis of a field cafeteria experiment. Comparison of twig quality was made among: 1) phenotypes, 2) different twig diameters, and 3) mean moose bite diameters. Chemical and morphological analyses of the trees indicated that twig fibre and tree/shoot size strongly affected moose bite diameter choice. Sight and chewing sensation are suggested to be the main browsing strategies used by moose. Moose adjusted the bite diameter among phenotypes on the criterion of similar food quality. The factors involved may play a multiple role in affecting moose foraging. Quantitative features of trees had no significant effects on moose bite diameter selection.
The muskrat Ondatra zibethicus is one of the semi‐aquatic rodents that has been introduced into m... more The muskrat Ondatra zibethicus is one of the semi‐aquatic rodents that has been introduced into many areas of the world. It is regarded as a most successful vertebrate invader. In northwestern Europe, it was introduced to Finland in 1919 and to the Kola Peninsula in 1931. From these areas, it spread ‘naturally’ to Sweden and Norway, respectively. Here the history of the introduction, dispersal, population development, impact on plant communities, impact on man, and indirect and direct effects on other animals in northwestern Europe are reviewed. The biological features of the muskrat are discussed in relation to the attributes of other vertebrates that are regarded as successful invaders.
A laser system and techniques which compensate for laser fluence drop off or losses of irradiatio... more A laser system and techniques which compensate for laser fluence drop off or losses of irradiation as an ablating laser beam is traversed on a curved surface (e.g., on corneal tissue). The disclosed ablating laser system and techniques compensate for fluence differentials from pulse-to-pulse by adjusting an appropriate parameter of a laser beam. In the preferred embodiment, the number of pulses imparted in the periphery, the size or shape of the ablating laser beam is adjusted with, e.g., a variable aperture placed in the beam delivery path, by changing a magnification of relay optics in the beam delivery path, or by increasing a number of ablation spots in peripheral portions of an ablation zone as compared with the number of ablation spots in a central portion of the ablation zone. The fluence is compensated for using empirically measured or theoretical fluence correction factors given the angle of the laser beam, size and shape of the ablation spot, etc. In addition to magnification adjustment, the present invention also employs the technique of changing the size of the aperture that is imaged o the eye to provide uniform energy density (i.e., fluence) throughout the entire area of the irradiation site. These techniques are used independently or in conjunction to reshape the curvature of the eye to correct myopia, hyperopia, astigmatism or combinations thereof.
Under the implementation of the Convention on Biological Diversity, a special emphasis has been p... more Under the implementation of the Convention on Biological Diversity, a special emphasis has been put on an integrated ecosystem approach. Some of the "Malawi principles" state that management objectives are a matter of societal choice, and that management should be decentralized to the lowest appropriate level. A key feature of the ecosystem approach includes conservation of ecosystem structure and function on a long term basis, while seeking an appropriate balance between conservation and use of biodiversity. The role of moose in the ecosystem and how the Malawi principles can be adopted in moose management were a focus of the 5th International Moose Symposium. All invited speakers and session chairs were asked to provide a brief summary of how they considered the Malawi principles to relate to the topic of their respective papers or sessions at the Symposium. Those summaries are given in this paper.
... John Pastor1 and Kjell Danell2 ... bouts to meet daily requirements of 5 – 10 kg per day (Bel... more ... John Pastor1 and Kjell Danell2 ... bouts to meet daily requirements of 5 – 10 kg per day (Belovsky and Jordan 1978, Renecker and Hudson 1986, Renecker and ... of leaves such that total leaf production during the growing season (removed leaves plus regrown leaves) did not differ ...
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