Linking environmental variation to population dynamics of a forest herb
Article first published online: 23 APR 2009
© 2009 The Authors. Journal compilation © 2009 British Ecological Society
Journal of Ecology
Volume 97, Issue 4, pages 666–674, July 2009
How to Cite
Dahlgren, J. P. and Ehrlén, J. (2009), Linking environmental variation to population dynamics of a forest herb. Journal of Ecology, 97: 666–674. doi: 10.1111/j.1365-2745.2009.01504.x
- Issue published online: 16 JUN 2009
- Article first published online: 23 APR 2009
- Received 10 October 2008; accepted 9 March 2009Handling Editor: Hans Jacquemyn
- Actaea spicata;
- habitat range;
- integral projection model;
- plant demography;
- population dynamics;
- pre-dispersal seed predation;
- soil potassium concentration
- 1Although necessary for understanding and predicting population dynamics, abiotic and biotic interactions have only rarely been coupled to demography and population dynamics.
- 2We estimated effects of 11 environmental factors on survival, growth and fertility of the perennial herb Actaea spicata and incorporated significant factors into integral projection models to assess their effect on population dynamics.
- 3Statistical models suggested that high soil potassium concentration increased individual growth and that seed predation and, to a lesser extent, canopy cover reduced seed production.
- 4Demographic models showed that both soil potassium concentration and pre-dispersal seed predation could reverse population growth from positive to negative. The observed range of soil potassium concentration corresponded to growth rates (λ) between 0.96 and 1.07, at mean observed seed predation intensity. At observed mean potassium concentration, growth rate ranged from 0.99 to 1.02 over observed seed predation intensities.
- 5Sensitivity of population growth rate to different vital rates strongly influenced the relative effects of the two factors. Elasticity analysis suggested that proportional changes in soil potassium concentration result in seven times larger effects on population growth rate than changes in seed predation.
- 6Synthesis. We conclude that relatively weak associations between environmental factors and vital rates can have substantial long-term effects on population growth. Approaches based on detailed demographic models, that simultaneously assess abiotic and biotic effects on population growth rate, constitute important tools for establishing the links between the environment and dynamics of populations and communities.