architecture of an antagonistic treefungus network the asymmetric influence of past evolutionary history敌对的treefungus网络的体系结构的不对称影响过去的进化历史.pdf

Architecture of an Antagonistic Tree/Fungus Network: The Asymmetric Influence of Past Evolutionary History 1 1,2 1 Corinne Vacher *, Dominique Piou , Marie-Laure Desprez-Loustau ´ ` ´ ´ ´ ˆ 1 Institut Scientifique de Recherche Agronomique (INRA), UMR1202 Biodiversite Genes et Communautes, Villenave d’Ornon, France, 2 Departement de la Sante des Forets, ` ˆ Ministere de l’Agriculture et de la Peche, Cenon, France Abstract Background: Compartmentalization and nestedness are common patterns in ecological networks. The aim of this study was to elucidate some of the processes shaping these patterns in a well resolved network of host/pathogen interactions. Methology/Principal Findings: Based on a long-term (1972–2005) survey of forest health at the regional scale (all French forests; 15 million ha), we uncovered an almost fully connected network of 51 tree taxa and 157 parasitic fungal species. Our analyses revealed that the compartmentalization of the network maps out the ancient evolutionary history of seed plants, but not the ancient evolutionary history of fungal species. The very early divergence of the major fungal phyla may account for this asymmetric influence of past evolutionary history. Unlike compartmentalization, nestedness did not reflect any consistent phylogenetic signal. Instead, it seemed to reflect the ecological features of the current species, such as the relative abundance of tree species and the life-history strategies of fungal pathogens. We discussed how the evolution of host range in fungal species may account for the observ