Uneven global distribution of food web studies under climate change

Abstract

Trophic interactions within food webs affect species distributions, coexistence, and provision of ecosystem services but can be strongly impacted by climatic changes. Understanding these impacts is therefore essential for managing ecosystems and sustaining human well‐being. Here, we conducted a global synthesis of terrestrial, marine, and freshwater studies to identify key gaps in our knowledge of climate change impacts on food webs and determine whether the areas currently studied are those most likely to be impacted by climate change. We found research suffers from a strong geographic bias, with only 3.5% of studies occurring in the tropics. Importantly, the distribution of sites sampled under projected climate changes was biased—areas with decreases or large increases in precipitation and areas with low magnitudes of temperature change were under‐represented. Our results suggest that understanding of climate change impacts on food webs could be broadened by considering more than two trophic levels, responses in addition to species abundance and biomass, impacts of a wider suite of climatic variables, and tropical ecosystems. Most importantly, to enable better forecasts of biodiversity responses to climate change, we identify critically under‐represented geographic regions and climatic conditions which should be prioritized in future research.

Global knowledge gaps in species interaction networks data

“…polar regions) consequences of climate change. Cameron et al (2019) reached a similar conclusion by focusing on food webs, and our analysis suggests that this worrying trend is, in fact, one that is shared by almost all types of interactions. All things considered, our current knowledge about the structure of ecological networks at the global scale leaves us under‐prepared to predict their response to a warming world.…”

“…Here we ask if the current Mangal database is fit for global‐scale synthesis research into ecological networks. A recent study by Cameron et al (2019) suggest that food webs are un‐evenly documented globally, but focused on metadata as opposed to actual datasets. Here, we conclude that interactions over most of the planet's surface are poorly described, despite an increasing amount of available data, due to temporal and spatial biases in data collection and digitization.…”

Novel tri‐isotope ellipsoid approach reveals dietary variation in sympatric predators

“…Studies of vertebrate marine predator trophic niches and dietary specializations have focussed on elasmobranchs (Gallagher et al, ; Matich et al, ; Shiffman, Kaufman, Heithaus, & Hammerschlag, ; Shipley et al, ) and birds (Bodey et al, ; Patrick et al, ), with most studies focussing on only a few co‐occurring species. There is a lack of isotopic information on resource partitioning among co‐occurring teleost predators (Matley, Tobin, Simpfendorfer, Fisk, & Heupel, ), particularly in the tropics (Cameron et al, ). This is despite the fact that coral reefs often support a high biomass and diversity of sympatric teleost predators (Friedlander, Sandin, DeMartini, & Sala, ; Stevenson et al, ), a factor thought to increase the occurrence of dietary specialization (Araújo et al, ).…”

Estimating the risk of species interaction loss in mutualistic communities

“…Our finding of widespread taxonomic consistency potentially allows properties of interactions to be inferred in regions without network data, even if such properties are only known for congeneric, confamiliar, or conorder interactions. This is important because species interaction networks are often cost-and time-intensive to collect, and coverage is highly biased geographically [46,47].…”