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Empirical and theoretical studies of population trends and extinction risks

Jeppsson, Tobias (2010). Empirical and theoretical studies of population trends and extinction risks. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2010:41
ISBN 978-91-576-7454-8
[Doctoral thesis]

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Empirical and theoretical approaches are needed to solve the current problem of increased extinction risk for many species. Thus, this thesis focuses on: (1) ways to estimate population trends for a large number of species, and (2) a predictive framework for identifying vulnerable populations from species traits or life history traits to allow for more proactive conservation actions. I estimated long-term population trends and range-abundance dynamics of longhorn beetles using Natural History Collections. In general, negative population trends were not accompanied by declines in range, but range increased among species with increasing populations. The analysis also exemplified how the results can be used in the red listing process. Linking life history traits and two metrics of extinction risk (population trend and red list classification) in long horn beetles showed that generation time, overwintering stage, larval host plant specialisation, adult activity period and body size were related to extinction risk, often with interaction effects between predictor variables. Variability in population size is an important factor affecting population extinction risk. I modelled the effects of demographic and environmental stochasticity on extinction risk in small populations, for a large range of life history types. Extinction risk due to demographic stochasticity increased with increasing fecundity and decreasing age of maturation, whereas effects of adult survival interacted with maturation age. Including environmental stochasticity showed that the qualitative relationship between extinction risk and life history types changed, but also that combined effects of both stochasticities on extinction risk were most significant in short-lived life histories. The results suggest that data from Natural History Collections can be used to estimate long-term population trends, and that population declines may be underestimated if estimated from changes in range. My studies also suggest that life history traits and species traits can be used to predict population vulnerability to extinction and, hence, that certain groups of species are more vulnerable to extinction than others.

Authors/Creators:Jeppsson, Tobias
Title:Empirical and theoretical studies of population trends and extinction risks
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2010
Number of Pages:49
ALLI. Jeppsson, T., Lindhe, A., Gärdenfors, U., Forslund, P. 2010. The use of historical collections to estimate population trends: a case study using Swedish longhorn beetles (Coleoptera: Cerambycidae). Accepted for publication by Biological Conservation. II. Jeppsson, T., Forslund, P. Factors explaining species differences in Red list status and long-term population trends in longhorn beetles – a comparative study (manuscript). III. Jeppsson, T., Forslund, P. Can life history type predict the effect of demographic stochasticity on extinction risk? (manuscript). IV. Forslund, P., Jeppsson, T., Pärt, T. Life history related effects of environmental and demographic stochasticity on extinction risk (manuscript).
Place of Publication:Uppsala
ISBN for printed version:978-91-576-7454-8
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:cerambycidae, endangered species, population dynamics, life cycle, animal ecology, nature conservation
Keywords:Population dynamics, Extinction, Life history, Population trends, Rarity, Demographic traits, Cerambycidae, Conservation biology
Permanent URL:
ID Code:2275
Department:(NL, NJ) > Dept. of Ecology
(S) > Dept. of Ecology
Deposited By: Tobias Jeppsson
Deposited On:22 Apr 2010 00:00
Metadata Last Modified:02 Dec 2014 10:17

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