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16
Effects of phenotypic complementarity and phylogeny on the nested structure of mutualistic networks
, 1919
"... Recent studies have started to unravel the structure of mutualistic networks, although few functional explanations underlying such structure have been explored. We used computer simulations to test whether complementarity between phenotypic traits of plants and animals can explain the pervasive tend ..."
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Cited by 17 (1 self)
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Recent studies have started to unravel the structure of mutualistic networks, although few functional explanations underlying such structure have been explored. We used computer simulations to test whether complementarity between phenotypic traits of plants and animals can explain the pervasive tendency of specialists to interact with proper subsets of species that generalists interact with (nested interactions), and how phylogeny affects such interaction patterns. Simultaneously, we assessed whether complementarity and phylogenetic structure were associated with patterns of interaction in a real mutualistic community. Simulation results support that highly nested networks can emerge from phenotypic complementarity, particularly when several traits are involved. The hierarchical structure of phylogenetic relations can also contribute to increased nestedness because traits determining complementarity are then inherited in a correlated fashion. Phylogenetic effects on resulting generalization levels are often low, but can be detected. Results from the empirical network support a relevant role of complementarity and phylogenetic history on interaction patterns. Our results demonstrate that these factors can contribute to nestedness, which emphasize the necessity of considering evolutionary mechanisms in studies of community structure. Plant-animal mutualistic networks depict mutually beneficial interactions between plants and their animal pollinators or seed dispersers. An increasing number of studies currently attempt to understand how these mutualistic networks are structured and, more specifically, how predictable structures may emerge and/or evolve (Olesen and Jordano 2002, Bascompte et al.
Analysis of a hyper-diverse seed dispersal network: modularity and underlying mechanisms
- Ecology Letters
, 2011
"... Abstract Mutualistic interactions involving pollination and ant-plant mutualistic networks typically feature tightly linked species grouped in modules. However, such modularity is infrequent in seed dispersal networks, presumably because research on those networks predominantly includes a single ta ..."
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Cited by 5 (2 self)
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Abstract Mutualistic interactions involving pollination and ant-plant mutualistic networks typically feature tightly linked species grouped in modules. However, such modularity is infrequent in seed dispersal networks, presumably because research on those networks predominantly includes a single taxonomic animal group (e.g. birds). Herein, for the first time, we examine the pattern of interaction in a network that includes multiple taxonomic groups of seed dispersers, and the mechanisms underlying modularity. We found that the network was nested and modular, with five distinguishable modules. Our examination of the mechanisms underlying such modularity showed that plant and animal trait values were associated with specific modules but phylogenetic effect was limited. Thus, the pattern of interaction in this network is only partially explained by shared evolutionary history. We conclude that the observed modularity emerged by a combination of phylogenetic history and trait convergence of phylogenetically unrelated species, shaped by interactions with particular types of dispersal agents.
Context-dependent fruit–frugivore interactions: Partner identities and spatio-temporal variations. Oikos 122
, 2013
"... Fruit–frugivore interactions are crucial for the dynamics and regeneration of most forested ecosystems. Still, we lack an understanding of the potential variation in the sign and strength of such interactions in relation to variations in the spatial and temporal ecological context. Here, we evaluate ..."
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Cited by 4 (1 self)
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Fruit–frugivore interactions are crucial for the dynamics and regeneration of most forested ecosystems. Still, we lack an understanding of the potential variation in the sign and strength of such interactions in relation to variations in the spatial and temporal ecological context. Here, we evaluated spatial (three sites) and temporal (two fruiting seasons) local variation in the sign (seed predation versus dispersal) and strength (frequency and quantity) of the interactions among six frugivorous mammals and a community of Mediterranean fleshy-fruited shrubs. We examined mammal faecal samples and quantified frequency of seed occurrence, number of seeds per faecal sample, seed species diversity and quality of seed treatment (i.e. percentage of undamaged seeds). The frequency of seed occurrence and number of seeds per faecal sample strongly varied among dispersers, sites, seasons and fruit species. For instance, fox Vulpes vulpes faeces showed between 6 and 40 times more seeds than wild boar Sus scrofa faeces in seasons or sites in which Rubus and Juniperus seeds were dominant. However, in seasons or sites dominated by Corema seeds, wild boar faeces contained up to seven times more seeds than fox faeces. Mammalian carnivores (fox and badger, Meles meles) treated seeds gently, acting mostly as dispersers, whereas deer (Cervus elaphus and Dama dama) acted mainly as seed predators. Interestingly, rabbit Oryctolagus cuniculus acted as either mostly seed disperser or seed predator depending on the plant species. Our results indicated that the sign of fruit–frugivore interactions depended mainly on the identity of the partners. For a particular fruit–frugivore pair, however, our surrogate
Build-up mechanisms determining the topology of mutualistic networks
, 2007
"... The frequency distribution of the number of interactions per species (i.e., degree distribution) within plant–animal mutualistic assemblages often decays as a power-law with an exponential truncation. Such a truncation suggests that there are ecological factors limiting the frequency of supergeneral ..."
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Cited by 2 (1 self)
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The frequency distribution of the number of interactions per species (i.e., degree distribution) within plant–animal mutualistic assemblages often decays as a power-law with an exponential truncation. Such a truncation suggests that there are ecological factors limiting the frequency of supergeneralist species. However, it is not clear whether these patterns can emerge from intrinsic features of the interacting assemblages, such as differences between plant and animal species richness (richness ratio). Here, we show that high richness ratios often characterize plant–animal mutualisms. Then, we demonstrate that exponential truncations are expected in bipartite networks generated by a simple model that incorporates build-up mechanisms that lead to a high richness ratio. Our results provide a simple interpretation for the truncations commonly observed in the degree distributions of mutualistic networks that complements previous ones based on biological effects.
Structure and dynamics of pollination networks: the past, present and future
, 2012
"... By far, most studies in ecology are about single species and their interactions with the surroundings, and this is also true in pollination ecology. However, species are members of communities of interacting species, i.e. networks. According to our definition, a network only includes species, whose ..."
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By far, most studies in ecology are about single species and their interactions with the surroundings, and this is also true in pollination ecology. However, species are members of communities of interacting species, i.e. networks. According to our definition, a network only includes species, whose linkage is spatially uncon-
Ecological Principles and Metrics for Improving Material Cycling Structures in Manufacturing Networks
"... A key element for achieving sustainable manufacturing systems is efficient and effective resource use. This potentially can be achieved by encouraging symbiotic thinking among multiple manufacturers and industrial actors and establish resource flow structures that are analogous to material flows in ..."
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A key element for achieving sustainable manufacturing systems is efficient and effective resource use. This potentially can be achieved by encouraging symbiotic thinking among multiple manufacturers and industrial actors and establish resource flow structures that are analogous to material flows in natural ecosystems. In this paper, ecological principles used by ecologists for understanding food web (FW) structures are discussed which can provide new insight for improving closed-loop manufacturing networks. Quantitative ecological metrics for measuring the performance of natural ecosystems are employed. Specifically, cyclicity, which is used by ecologists to measure the presence and strength of the internal cycling of materials and energy in a system, is discussed. To test applicability, groupings of symbiotic eco-industrial parks (EIP) were made in terms of the level of internal cycling in the network structure (high, medium, basic, and none) based on the metric cyclicity. None of the industrial systems analyzed matched the average values and amounts of cycling seen in biological ecosystems. Having detritus actors, i.e., active recyclers, is a key element for achieving more complex cycling behavior. Higher cyclicity values also correspond to higher amounts of indirect cycling and pathway proliferation rate, i.e., the rate that the number of paths increases as path length increases. In FWs, when significant cycling is present, indirect flows dominate direct flows. The application of these principles has the potential for novel insights in the context of closed-loop manufacturing systems and sustainable manufacturing.
5þ model YJTBI: 4807 Prod:Type:FTP pp:129ðcol:fig::1Þ ED:AnupamaDeviY PAGN:Sakthi SCAN: ARTICLE IN PRESS 1 3 5 Journal of Theoretical Biology] (]]]])]]]–]]]
"... The frequency distribution of the number of interactions per species (i.e., degree distribution) within plant–animal mutualistic assemblages often decays as a power-law with an exponential truncation. Such a truncation suggests that there are ecological factors limiting the frequency of supergeneral ..."
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The frequency distribution of the number of interactions per species (i.e., degree distribution) within plant–animal mutualistic assemblages often decays as a power-law with an exponential truncation. Such a truncation suggests that there are ecological factors limiting the frequency of supergeneralist species. However, it is not clear whether these patterns can emerge from intrinsic features of the interacting assemblages, such as differences between plant and animal species richness (richness ratio). Here, we show that high richness ratios often characterize plant–animal mutualisms. Then, we demonstrate that exponential truncations are expected in bipartite networks generated by a simple model that incorporates build-up mechanisms that lead to a high richness ratio. Our results provide a simple interpretation for the truncations commonly observed in the degree distributions of mutualistic networks that complements previous ones based on biological effects.
CT 2.2.3 Modelling bipartite cooperation in ecological and organizational networks
"... In theoretical ecology, stochastic models incorporating simple interaction rules have recently proved remarkably successful at reproducing some of the most important structural properties of real food webs (Williams and Martinez, 2000; Cattin et al, 2004). It has been shown that such models only nee ..."
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In theoretical ecology, stochastic models incorporating simple interaction rules have recently proved remarkably successful at reproducing some of the most important structural properties of real food webs (Williams and Martinez, 2000; Cattin et al, 2004). It has been shown that such models only need to satisfy two basic conditions
Journal of Theoretical Biology] (]]]])]]]–]]] Analysis and assembling of network structure in mutualistic systems
, 2006
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"... Integrating frugivory and animal movement: a review of the evidence and implications for scaling seed dispersal ..."
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Integrating frugivory and animal movement: a review of the evidence and implications for scaling seed dispersal
