Review: Ecological networks – beyond food webs

Abstract

Summary 1.A fundamental goal of ecological network research is to understand how the complexity observed in nature can persist and how this affects ecosystem functioning. This is essential for us to be able to predict, and eventually mitigate, the consequences of increasing environmental perturbations such as habitat loss, climate change, and invasions of exotic species. 2. Ecological networks can be subdivided into three broad types: 'traditional' food webs, mutualistic networks and host-parasitoid networks. There is a recent trend towards cross-comparisons among network types and also to take a more mechanistic, as opposed to phenomenological, perspective. For example, analysis of network configurations, such as compartments, allows us to explore the role of co-evolution in structuring mutualistic networks and host-parasitoid networks, and of body size in food webs. 3. Research into ecological networks has recently undergone a renaissance, leading to the production of a new catalogue of evermore complete, taxonomically resolved, and quantitative data. Novel topological patterns have been unearthed and it is increasingly evident that it is the distribution of interaction strengths and the configuration of complexity, rather than just its magnitude, that governs network stability and structure. 4. Another significant advance is the growing recognition of the importance of individual traits and behaviour: interactions, after all, occur between individuals. The new generation of high-quality networks is now enabling us to move away from describing networks based on species-averaged data and to start exploring patterns based on individuals. Such refinements will enable us to address more general ecological questions relating to foraging theory and the recent metabolic theory of ecology. 5. We conclude by suggesting a number of 'dead ends' and 'fruitful avenues' for future research into ecological networks.

Food webs: reconciling the structure and function of biodiversity

“…The use of food webs to describe fluxes of energy between species was mired for many years in debate over inclusiveness, approaches to sampling, and the meaning of some of the food-web attributes that can be calculated [13][14][15]. There is now a clear understanding of the limitations of older data and the need for methodological rigour in describing food webs [14,15].…”

“…There is now a clear understanding of the limitations of older data and the need for methodological rigour in describing food webs [14,15]. With those concerns dealt with, food-web ecology can be placed in the context of other major sub-disciplines of ecology.…”

Caught in the web: Spider web architecture affects prey specialization and spider–prey stoichiometric relationships

“…Such networks, which look at the degree to which predators feed upon a prey community, can be used to observe both qualitative properties—which species are interacting—or quantitative measures that consider the strength of the species interactions (Ings et al., 2009; Williams & Martinez, 2000). While qualitative descriptors are based on the presence or absence of trophic links, quantitative metrics can include bioenergetics estimations.…”

Inferring species interaction networks from species abundance data: A comparative evaluation of various statistical and machine learning methods

“…Understanding and predicting how ecosystems will respond to change requires untangling the 2 tangled bank and is of enormous importance during a period of rapid global change. Yet such a task can seem impossible given the enormous complexity of ecological systems and the excruciating fieldwork needed to quantify even the simplest of foodwebs (Memmott et al, 2000;Ings et al, 2009). …”