title: The dynamics of ant mosaics in tropical rainforests characterized using the Self-Organizing Map algorithm.
abstract: Ants, the most abundant taxa among canopy-dwelling animals in tropical rainforests, are mostly represented by territorially dominant arboreal ants (TDAs) whose territories are distributed in a mosaic pattern (arboreal ant mosaics). Large TDA colonies regulate insect herbivores, with implications for forestry and agronomy. What generates these mosaics in vegetal formations, which are dynamic, still needs to be better understood. So, from empirical research based on 3 Cameroonian tree species (Lophira alata, Ochnaceae; Anthocleista vogelii, Gentianaceae; and Barteria fistulosa, Passifloraceae), we used the Self-Organizing Map (SOM, neural network) to illustrate the succession of TDAs as their host trees grow and age. The SOM separated the trees by species and by size for L. alata, which can reach 60 m in height and live several centuries. An ontogenic succession of TDAs from sapling to mature trees is shown, and some ecological traits are highlighted for certain TDAs. Also, because the SOM permits the analysis of data with many zeroes with no effect of outliers on the overall scatterplot distributions, we obtained ecological information on rare species. Finally, the SOM permitted us to show that functional groups cannot be selected at the genus level as congeneric species can have very different ecological niches, something particularly true for Crematogaster spp., which include a species specifically associated with B. fistulosa, nondominant species and TDAs. Therefore, the SOM permitted the complex relationships between TDAs and their growing host trees to be analyzed, while also providing new information on the ecological traits of the ant species involved.
authors: CNRS, Laboratoire Écologie Fonctionnelle et Environnement (UMR-CNRS 5245), 31062, Toulouse, France.|Université de Toulouse, UPS, INP, Ecolab, 118 route de Narbonne, 31062, Toulouse, France.|Écologie des Forêts de Guyane, Campus agronomique, BP 316, 97387, Kourou cedex, France.
authors: Alain
authors: A
authors: Dejean
authors: CNRS, Laboratoire Écologie Fonctionnelle et Environnement (UMR-CNRS 5245), 31062, Toulouse, France.|Université de Toulouse, UPS, INP, Ecolab, 118 route de Narbonne, 31062, Toulouse, France.
authors: Frédéric
authors: F
authors: Azémar
authors: CNRS, Laboratoire Écologie Fonctionnelle et Environnement (UMR-CNRS 5245), 31062, Toulouse, France.|Université de Toulouse, UPS, INP, Ecolab, 118 route de Narbonne, 31062, Toulouse, France.
authors: Régis
authors: R
authors: Céréghino
authors: Biodiversity Monitoring and Assessment Unit, Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000, Brussels, Belgium.
authors: Maurice
authors: M
authors: Leponce
authors: CNRS, Laboratoire Microorganismes, Génome et Environnement (UMR-CNRS 6023), Université Blaise Pascal, Complexe Scientifique des Cézeaux, 63177, Aubière cedex, France.|Clermont Université, Université Blaise Pascal, LMGE, BP 10448, F-63000, Clermont-Ferrand, France.
authors: Bruno
authors: B
authors: Corbara
authors: Écologie des Forêts de Guyane, Campus agronomique, BP 316, 97387, Kourou cedex, France.
authors: Jérôme
authors: J
authors: Orivel
authors: CNRS, Laboratoire Écologie Fonctionnelle et Environnement (UMR-CNRS 5245), 31062, Toulouse, France.|Université de Toulouse, UPS, INP, Ecolab, 118 route de Narbonne, 31062, Toulouse, France.
authors: Arthur
authors: A
authors: Compin
mesh_terms: D000465:Algorithms; D000818:Animals; D001000:Ants / Q000502:physiology*; D002163:Cameroon; D017753:Ecosystem; D019684:Magnoliopsida / Q000254:growth & development; D011157:Population Dynamics; D065947:Rainforest; D014197:Trees / Q000254:growth & development*; D014329:Tropical Climate
keywords: ant plant relationships; dynamics of associations; myrmecophytes; tropical rainforests