How life history influences population dynamics in fluctuating environments.

Bernt-Erik Sæther (1) , Tim Coulson (2) , Vidar Grøtan (1) , Steinar Engen (3) , Romain Altwegg (4) , Kenneth B. Armitage (5) , Christophe Barbraud (6) , Peter H. Becker (7) , Daniel T. Blumstein (8) , F Stephen Dobson (9, 10) , Marco Festa-Bianchet (11) , Jean-Michel Gaillard (12) , Andrew Jenkins (13) , Carl Jones (14, 15) , Malcolm A.C. Nicoll (16) , Ken Norris (17) , Madan K. Oli (18) , Arpat Ozgul (18, 19) , Henri Weimerskirch (6)

1 Centre for Conservation Biology
2 Division of Biology and Centre for Population Biology
3 Norwegian University of Science and Technology - Department of Mathematical Sciences
4 Kirstenbosch Research Centre
5 Department of Ecology and Evolutionary Biology
6 CEBC - Centre d'Études Biologiques de Chizé
7 Institute of Avian Research
8 Department of Ecology and Evolutionary Biology
9 CEFE - Centre d’Ecologie Fonctionnelle et Evolutive
10 Department of Zoology
11 UdeS - Département de biologie [Sherbrooke]
12 Biodémographie évolutive
13 DST/NRF Centre of Excellence
14 Mauritian Wildlife Foundation
15 Durrell Wildlife Conservation Trust
16 Centre for Agri-Environment Research (CAER)
17 Centre for Agro-Environmental Research
18 Department of Wildlife Ecology and Conservation
19 IEU - Department of Evolutionary Biology and Environmental Studies

A major question in ecology is how age-specific variation in demographic parameters influences population dynamics. Based on long-term studies of growing populations of birds and mammals, we analyze population dynamics by using fluctuations in the total reproductive value of the population. This enables us to account for random fluctuations in age distribution. The influence of demographic and environmental stochasticity on the population dynamics of a species decreased with generation time. Variation in age-specific contributions to total reproductive value and to stochastic components of population dynamics was correlated with the position of the species along the slow-fast continuum of life-history variation. Younger age classes relative to the generation time accounted for larger contributions to the total reproductive value and to demographic stochasticity in "slow" than in "fast" species, in which many age classes contributed more equally. In contrast, fluctuations in population growth rate attributable to stochastic environmental variation involved a larger proportion of all age classes independent of life history. Thus, changes in population growth rates can be surprisingly well explained by basic species-specific life-history characteristics.

Mots clés: stochastic demography; life history; reproductive value; demographic stochasticit; environmental stochasticity

Domaines: Sciences de l'environnement

Bernt-Erik Sæther, Tim Coulson, Vidar Grøtan, Steinar Engen, Romain Altwegg, et al.. How life history influences population dynamics in fluctuating environments.. The American Naturalist, 2013, 182 (6), pp.743-759. ⟨10.1086/673497⟩. ⟨hal-00853677⟩