Tropical Biology Section
Zalamea, Paul Camilo , Heuret, Patrick , Nicolini, Eric , Sarmiento, Carolina , Fonty, Emile , Rutishauser, Ervan , Stevenson, Pablo .
The coexistence of two Cecropia species: a morphological study approach.
The genus Cecropia includes pioneer trees that colonize canopy gaps and cleared areas. It is widely distributed from Mexico to Northern Argentina. Cecropia trees have architecture, which corresponds to the Rauh’s architectural model. In recent studies we have found that C. obtusa and C. sciadophylla, in French Guiana, have a strong annual periodicity for growth, branching and flowering processes, with annual emission of 35 nodes for C. obtusa and 25 for C. sciadophylla. Those species show different life histories since C. sciadophylla has longer life expectancy. In addition, C. sciadophylla is found more frequently in forest gaps, although in French Guiana mixed populations are found. The aim of this work was to compare developmental strategies of both species in three different field stations in French Guiana and to determine how these two species coexist during its first years of life. We studied a 20-year old population of C. sciadophylla at Saint Elie’s Road, a 10-year old population of C. obtusa at Paracou’s field station, and a 7-year old mixed population at Counami’s Road. C. sciadophylla emits 25 nodes per year in both studied populations, while C. obtusa emits 35 nodes in the monospecific population and 30 nodes in the mixed population. In the monocaule stage, the lower number of nodes emitted by C. sciadophylla compared to C. obtusa is compensated with a higher internodal length, which allows finding individuals with similar ages and lengths, but different number of nodes. The branching and flowering processes start on average three years before in C. obtusa, however for 12-year old individuals we observed a dominancy of C. sciadophylla over C. obtusa. In the mixed population it is likely that the different life histories would decrease competition effects allowing coexistence of both species during the first stages of life.
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1 - IRD, U.M.R botanique et bioinformatique de l\'architecture des plantes, TA40/PS2, Bd. de la Lironde,
, Montpellier, 34086, France
2 - Inra, U.M.R botanique et bioinformatique de l'architecture des plantes (AMAP), TA A-51/Ps2, Montpellier Cedex 5, 34398, France
3 - CIRAD, U.M.R botanique et bioinformatique de l\'architecture des plant, TA40/PS2, Bd. de la Lironde, Montpellier, 34086, France
4 - Universidad de Los Andes, Departamento de Ciencias Biológicas, Cr. 1a No. 18A-10, Bogotá, Colombia
5 - École Nationale du Génie Rural des Eaux et des Forêts, 648, rue Jean-François Breton, Montpellier, 34086, France
6 - CIRAD, U.M.R botanique et bioinformatique de l\'architecture des plant, TA40/PS2, Bd. de la Lironde, Montpellier, 34086, France
7 - Ciem, Departamento de Ciencias Biológicas, Universidad de los Andes, Cr. 1a No. 18A-10, Bogotá, Colombia
Node production rate
Presentation Type: Oral Paper:Papers for Sections
Date: Monday, July 28th, 2008
Time: 4:30 PM