Architecture of an Antagonistic Tree/Fungus Network: The Asymmetric Influence of Past Evolutionary History

Abstract

BackgroundCompartmentalization 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 FindingsBased 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 observed nested patterns.Conclusion/SignificanceOverall, our analyses emphasized how the current complexity of ecological networks results from the diversification of the species and their interactions over evolutionary times. They confirmed that the current architecture of ecological networks is not only dependant on recent ecological processes.

Influence of plant resistance traits in selectiveness and species strength in a tropical plant‐herbivore network

“…Th us, we lack a comprehensive understanding of the diversity and evolution of biotic interactions ( Th ompson, 2005 ). However, recent complex network analyses have proven effective for exploring the patterns of mega-diverse interactions that commonly occur in nature ( Bascompte, 2009 ) and have been useful for testing hypotheses regarding the processes infl uencing the structure of mutualistic Olesen et al, 2007 ;Vázquez et al, 2009 ) and antagonistic networks ( Vacher et al, 2008 ;Rezende et al, 2009 ;Cagnolo et al, 2011 ;Villa-Galaviz et al, 2012 ;López-Carretero et al, 2014 ).…”

Defining invasiveness and invasibility in ecological networks

“…Recent progress in resolving the complexity-stability debate has involved exploring the causal relationship between the architecture and stability of many mutualistic (e.g., plantfrugivore and plant-pollinator), trophic (food web) and antagonistic (predator-prey and host-parasite/pathogen) networks (e.g. Memmott et al 2004;Eklöf and Ebenman 2006;Bascompte et al 2006;Burgos et al 2007;Estrada 2007;Bastola et al 2009;Kiers et al 2010;Thébault and Fontaine 2010;Brose 2011;de Visser et al 2011;Stouffer and Bascompte 2011;James et al 2012), and explaining emergent network structures using dynamic network models with adaptive and random species rewiring (van Baalen et al 2001;Kondoh 2003;Rezende et al 2007;Vacher et al 2008;Valdovinos et al 2010;Zhang et al 2011;Suweis et al 2013;Minoarivelo et al 2014;Nuwagaba et al 2015).…”

Phylogenetic congruence between subtropical trees and their associated fungi

“…Whereas networks of multiple pathogens with multiple hosts dominate natural systems (Barrett et al., 2009; Vacher, Piou, & Desprez‐Loustau, 2008), most previous work has emphasized single‐pathogen infections in a single plant species. Some recent studies have provided a window into the structure of bipartite networks of belowground plant–fungal interactions dominated by mycorrhizal fungi (e.g., Montesinos‐Navarro, Segarra‐Moragues, Valiente‐Banuet, & Verdú, 2012; Taylor et al., 2014; Toju, Guimarães, Olesen, & Thompson, 2014; Toju, Sato, et al., 2013, Toju, Yamamoto, et al., 2013), but such networks have included <2% putative pathogens.…”