Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Polish Journal of Ecology

2 2000

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Understanding the dynamics of bank vole populations: demographic variability, stochasticity and density dependence

Yoccoz N., Stenseth N.

Polish Journal of Ecology

2000

Vol. 48, Suppl.

75-86

The observed variability of population dynamics in influenced by many interacting components, most of them being difficult to estimate. Sampling variance, demographic and environmental stochasticity, together with density dependence and more deterministic changes in the environment such as changes in forestry practice and landscape patterns, simultaneously affect our understanding of bank vole population dynamics patterns. Integrating these difference variability components in a common framework is a considerable challenge. We explore in this paper some of the tools currently available for analysing population dynamics and demographic patterns in the bank vole, Clethrionomys glareolus. The study of an alpine population of bank voles is used to illustrate how demographic studies and time-series analysis may be associated in the future.

Geographical differences in size, reproduction and behaviour of bank voles in relation to density variations

Yoccoz N., Hansson L., Ims R.

Polish Journal of Ecology

2000

Vol. 48, Suppl.

63-72

The bank vole in Europe is hardly genetically differentiated, except in northern Fennoscandia, but shows large phenotypic variation. Body weight has been studied in the field and in the laboratory. Large bank voles are known in northern cyclic populations found on islands and in alpine areas. Reproductive patterns show that the length of the breeding season and the maturation processes may be more influenced by the fluctuation patterns than the length of the vegetative period. Behavioural differences are also known to occur between individuals from northern cyclic populations and individuals from southern stable populations. The relative importance of density fluctuations patterns and environmental harshness in causing geographical variation patterns is not known.