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Age structure of boreal willows and fluctuations in herbivore populations

Published online by Cambridge University Press:  05 December 2011

L. Ericson
Affiliation:
Department of Ecological Botany, University of Umeå, S–901 87 Umeå, Sweden
T. Elmqvist
Affiliation:
Department of Ecological Botany, University of Umeå, S–901 87 Umeå, Sweden
K. Jakobsson
Affiliation:
Department of Ecological Botany, University of Umeå, S–901 87 Umeå, Sweden
K. Danell
Affiliation:
Department of Wildlife Ecology, Swedish University of Agricultural Sciences, S–901 83 Umeå, Sweden
A. Salomonson
Affiliation:
Department of Wildlife Ecology, Swedish University of Agricultural Sciences, S–901 83 Umeå, Sweden
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Synopsis

The age structure, both on the ramet and the genet level of boreal willow populations (Salix myrsinifolia-phylicifolia) was studied in relation to fluctuations in populations of voles (Clethrionomys glareolus and Microtus agrestis). Willow ramets were collected from four different areas in the coastal part of Sweden and Finland at the Bothnian Bay. In each area we selected one mainland and one island locality. The ramets, as well as the scars left by bark-eating voles on the ramets, were aged. We found in general a high correlation between ramet ages and peaks in vole cycles (based on frequencies of scars).

From a sample of 79 willow clones where all ramets were aged, more than half of the ramets were produced the summer following a vole peak. Field surveys of seedling survival showed that successful establishment is mainly confined to disturbed ground (vole run-ways, etc.) in connection with vole peak years. It is concluded that the age structure both at the genet and the ramet level in boreal willow populations are strongly influenced by the fluctuations in vole populations. The consequences of vole herbivory are manifold, e.g. periodic damage of willows may delay senescence of individual genets and delay the rate of succession due to increased opportunities for willow recruitment.

Type
Invited papers
Copyright
Copyright © Royal Society of Edinburgh 1992

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References

Ahti, T., Hämet-Ahti, L. & Jalas, J. 1968. Vegetation zones and their sections in northwestern Europe. Annales Botanici Fennici 5, 169211.Google Scholar
Crawley, M. J. 1983. Herbivory. The dynamics of animal–plant interactions. Oxford: Blackwell Scientific Publications.Google Scholar
Crisp, M. D. & Lange, R. T. 1976. Age structure distribution and survival under grazing of the arid-zone shrubs Acacia burkittii. Oikos 27, 8692.CrossRefGoogle Scholar
Danell, K., Ericson, L. & Jakobsson, K. 1981. A method for describing former fluctuations of voles. Journal of Wildlife Management 45, 1018–21.CrossRefGoogle Scholar
Danell, K., Elmqvist, T., Ericson, L., & Salomonson, A. 1985. Sexuality in willows and preferences by bark-eating voles: defence or not? Oikos 44, 8290.CrossRefGoogle Scholar
Elmqvist, T., Danell, K., Ericson, L., & Salomonson, A. 1987. Flowering, shoot production and vole bark herbivory in a boreal willow. Ecology 68, 1623–9.CrossRefGoogle Scholar
Elmqvist, T., Ericson, L., Danell, K. & Salomonson, A. 1988. Latitudinal sex ratio variation in willows Salix spp., and gradients in vole herbivory. Oikos 51, 259–66.CrossRefGoogle Scholar
Falinski, J. B. 1980a. Vegetation dynamics and sex structure of the populations of pioneer woody plants, Vegetatio 43, 2338.CrossRefGoogle Scholar
Falinski, J. B. 1980b. Changes in the sex- and age-ratio in populations of pioneer dioecious woody species (Juniperus, Populus, Salix) in connection with the course of vegetation succession in abandoned farmlands. Ekologia Polska 28, 327–65.Google Scholar
Grubb, P. J. 1977. The maintenance of species richness in plant communities: The importance of the regeneration niche. Biological Review 52, 107–45.CrossRefGoogle Scholar
Hansson, L., Löfqvist, J. & Nilsson, A. 1978. Population fluctuations in insectivores and small rodents in northernmost Fennoscandia. Zeitschrift für Säugetierkunde 43, 7592.Google Scholar
Hokkanen, H. & Raatikainen, M. 1977. Yield, vegetation and succession in reserved fields in Central Finland. Journal of the Scientific Agricultural Society of Finland 49, 221–38.Google Scholar
Hörnfeldt, B. 1991. Cycles of voles, predators and alternative prey in boreal Sweden (Ph.D. thesis, University of Umeå, Sweden).Google Scholar
Kalela, O. 1962. On the fluctuation in numbers of arctic boreal rodents as a problem of production biology. Annales Academicae Scientalis Fennici A IV Biologici 66, 138.Google Scholar
Kopponen, T., Isoviita, P. & Lammes, T. 1977. The bryophytes of Finland: an annotated checklist. Flora Fennica 6, 177.Google Scholar
Laine, K. & Henttonen, H. 1983. The role of plant production in microtine cycles in northern Fennoscandia. Oikos 40, 407–18.CrossRefGoogle Scholar
Lidicker, W. Z. Jr. 1973. Regulation of numbers in an island of a southern Appalachian virgin forest. Ecology 61, 1169–84.Google Scholar
Myrberget, S 1982. Fluctuations in microtine populations in an island area in northern Norway 1958–1981. Fauna Norvegica, Ser. A 3, 711.Google Scholar
Nygren, J. 1980. Genetic variation in allozymes and behaviour in field vole populations and its implications for demographic changes. Ph.D. thesis, University of Umeå, Sweden.Google Scholar
Pokki, J. 1981. Distribution, demography and dispersal of the field vole, Microtus agrestis (L.). in the Tvärminne archipelago, Finland. Acta Zoologica Fennica 164, 148.Google Scholar
Raatikainen, M. & Raatikainen, T. 1975. Yield, composition and dynamics of flora in grasslands for hay. Annales Agriculturae Fenniae 14, 57191 (in Finnish, English summary).Google Scholar
Silander, J. A. Jr. 1983. Demographic variation in the Australian desert Cassia under grazing pressure. Oecologia (Berlin) 60, 227–33.CrossRefGoogle ScholarPubMed