Journal of Tropical Ecology (2008) 24:493–503. Copyright © 2008 Cambridge University Press doi:10.1017/S0266467408005312 Printed in the United Kingdom Demography and life history of two rattan species, Eremospatha macrocarpa and Laccosperma secundiflorum, in C ˆ ote d’Ivoire Kouadio I. Kouassi ∗ † 1 ,S´ ebastien Barot†, Jacques Gignoux‡ and Iri ´ e A. Zoro Bi ∗ ∗ Universit ´ e d’Abobo-Adjam ´ e, UFR des Sciences de la Nature, 02 BP 801 Abidjan 02, C ˆ ote d’Ivoire † Laboratoire d’Ecologie des Sols Tropicaux (LEST), UMR 137, IRD, 32 Avenue Henri Varagnat, 93143, Bondy, France ‡ Laboratoire de Biochimie et Ecologie des Milieux Continentaux (Biodiversit ´ e et fonctionnement des Ecosyst ` emes), ENS, 46 rue d’Ulm 75230 Paris Cedex 05 (Accepted 26 July 2008) Abstract: Two rattans species were studied in Cˆ ote d’Ivoire using a stage-classified matrix model to compare their demography and life histories. Respectively 854 and 1009 genets of Eremospatha macrocarpa (pleonanthic) and Laccosperma secundiflorum (hapaxanthic) were censused every 6 mo over 18 mo. The population growth rates of E. macrocarpa (λ = 0.979) and L. secundiflorum (λ = 0.959) were not significantly different from 1. This indicates that the populations were close to equilibrium. However, the difference between the stable stage distributions and the observed distributions indicated temporal variation in vital rates. Elasticity analysis showed that growth and fecundity had lower contributions to λ than the survival rates for the two species. A Life Table Response Experiment revealed that the survival of the first juvenile stage (all stems < 6 m in length), fecundity, growth of the second juvenile stage (at least one stem > 6 m in length) and adult (reproductive) survival highly contribute to the differences between the demography of the two species. Reproduction is postponed longer for L. secundiflorum than for E. macrocarpa and the mean remaining life span for adult genets is shorter for L. secundiflorum than for E. macrocarpa. Finally, our results suggest the existence of two trade-offs within reproduction which suggest that, although the two species have different demographic features, the λ of their populations are not significantly different from 1. Key Words: age estimation, elasticity, life-table response experiments, non-timber forest products, palm, population growth rate, stage-classified matrix model, tropical forest INTRODUCTION Life-history evolution is an important field of modern ecology (Begon et al. 2006, Stearns 1977). A useful approach is to compare the life histories of related organisms to determine how evolution has shaped the relationship between different life-history traits. Because the population growth rate is a function of all life- history parameters, changes in these parameters will cause changes in the growth rate (Caswell 2001, Stearns & Hoekstra 2000). In this context, palm trees are suitable models to study perennial plant demography and life history (Barot & Gignoux 1999). In particular, the relatively simple morphology of palm trees makes it is easy to define stages based on morphological traits and size. Matrix population models have been widely used to analyse the demography of palms (Barot et al. 2000, 1 Corresponding author. Email: kouadioignace@yahoo.fr Bernal 1998, Bullock 1980, De Steven 1986, 1989; Escalante et al. 2004, Pi ˜ nero et al. 1984, Rodriguez- Buritica et al. 2005, Souza & Martins 2006) and to improve the exploitation of palm populations (Anderson & Putz 2002, Balick 1987, Endress et al. 2004, Olmsted & Alvarez-Buylla 1995, Ratsirarson et al. 1996). Matrix models constitute useful tools to analyse the persistence of populations, to describe life histories, and to compare the demography of different populations or species (Caswell 2001). For plants, these models are usually stage- classified and require the estimations of the transition probabilities between stages as well as fecundities (Caswell 2001, De Matos & Matos 1998, Ramula & Lehtil ¨ a 2005, Silvertown et al. 1993). The models also allow the calculation of age-based parameters (Barot et al. 2002, Cochran & Ellner 1992) such as the mean ages in different stages. We present here the first matrix model for the genets of two African rattan species: Eremospatha macrocarpa (Mann & Wendl.) Wendl. and Laccosperma secundiflorum (P. Beauv.) Kuntze. Despite the existence of over 600