Who Is Where in Marine Food Webs? A Trait-Based Analysis of Network Positions

Abstract

Networks of trophic interactions provide a lot of information on the functioning of marine ecosystems. Beyond feeding habits, three additional traits (mobility, size, and habitat) of various organisms can complement this trophic view. The combination of traits and food web positions are studied here on a large food web database. The aim is a better description and understanding of ecological roles of organisms and the identification of the most important keystone species. This may contribute to develop better ecological indicators (e.g., keystoneness) and help in the interpretation of food web models. We use food web data from the Ecopath with Ecosim (EwE) database for 92 aquatic ecosystems. We quantify the network position of organisms by 18 topological indices (measuring centrality, hierarchy, and redundancy) and consider their three, categorical traits (e.g., for mobility: sessile, drifter, limited mobility, and mobile). Relationships are revealed by multivariate analysis. We found that topological indices belong to six different categories and some of them nicely separate various trait categories. For example, benthic organisms are richly connected and mobile organisms occupy higher food web positions.

Comparative Network Analysis of Aquatic Ecosystems: Linking Structure and Function

“…Our findings quantitatively showed that mobility and body size are important in structuring marine communities, but habitat in a binary format (benthic or pelagic) does not predict network position (Endrédi et al, 2021;Podani et al, 2022). This is in agreement with the conclusion of Costello et al (2015), who recommended including the mobility and body size traits in the WoRMS trait database.…”

“…for the Chesapeake Bay (Jordán et al, 2006) and a selection of 9 marine food webs (Jordán et al, 2007). For example, it is clear that certain centrality indices (e.g., CC and BC) and K components (K and Kindir) form a strong relationship (Jordán et al, 2006;Jordán et al, 2007;Endrédi et al, 2021;Gouveia et al, 2021), while other K components (Kbu, Kdir) are more variable. Fortunately, Ktd clusters strongly with other top-down indices (s', TL), which helps with assessing its role.…”

“…For instance, the analysis of food webs makes it possible to identify species of central importance (e.g., keystone species) or those that threaten network structure (e.g., invasive species). A group's function is inferred from network properties with the use of ecological indicators (Heymans et al, 2014), biological traits (Endrédi et al, 2021), or emerging patterns (Cury et al, 2000), and validated by empirical observations (Paine, 1969;Paine 1980). By comparing the topology of various food webs from around the world, patterns start to emerge, which then help explain underlying functionality (Dunne, 2009;Heymans et al, 2014).…”

Catalyzing progress in the blue economy through joint marine microbiome research across the Atlantic

“…Goals of the project include understanding microbiomes to support the blue bioeconomy, understanding microbiome interactions within the plastisphere, and establishing a better understanding of the links between land, oceans, climate, and human activity. Microbial diversity investigations through AtlantECO have provided snapshots of community diversity across time and space, primarily measured with 'omics tools (e.g., Benedetti et al, 2021;Brandão et al, 2021;Chaffron et al, 2021;Endredi et al, 2021). Consistent with the roadmaps, AtlantECO aims to increase marine microbiome observations in the southern oceans, including the coasts of South America.…”

Structure and Characteristics of Plant-Frugivore Network in an Urban Park: A Case Study in Nanjing Botanical Garden Mem. Sun Yat-Sen

“…Macroscopically, plant-frugivore networks are not only affected by different scales of time, space, and climate [23][24][25], but are also very sensitive to the loss of habitats resulting from urban production activities and the consequent decline of native plants and animals [26,27]. From the micro plant-frugivore interaction process, the ecological traits of species are important factors affecting plantfrugivore networks: the fruit (seed) size, color, and crop of plants affect the foraging choice of frugivore birds [28][29][30], while the body size, mouth peak length, and tail length of frugivore birds are used as the characteristics of feeding amount, mode, and flight ability to limit the foraging niche [31,32]. Not only that, there is a matching of phenological and ecological traits between fruit plants and frugivore birds [33][34][35][36].…”