History of co‐occurrence shapes predation effects on functional diversity and structure at low latitudes

Abstract

The intensity of biotic interactions is hypothesized to increase towards the equator. Predation can have a stronger effect on prey composition, biomass and taxonomic diversity in tropical regions compared to higher latitudes. Whether predation also shapes patterns of functional diversity and structure of prey communities, however, has rarely been explored across a latitudinal gradient. History of co‐occurrence between predators and prey may also shape the outcome of the interaction, and increased novelty of introduced prey may lead to stronger trait responses. We investigated the influence of predation on trait responses of prey communities across 12 sites in four regions, from the sub‐arctic to the tropics, using a field experiment in invaded coastal habitats. Prey communities experienced ambient or reduced predation pressure during assembly, and the effect of predation on functional diversity and structure of whole communities as well as their native and introduced components was assessed. Overall, predation increased functional diversity in the tropics, but effects were evident for introduced species only. Predation also shaped functional structure of low‐latitude communities, but effects were strongest for native species in subtropical Mexico and introduced species in tropical Panama. Key traits driving shifts in functional structure were related to palatability and reproduction. In the tropics, the strong predation present under ambient conditions reduced the abundance of palatable traits in introduced prey relative to low‐predation treatments, while in the subtropics, ambient predation increased the abundance of palatable traits in native prey. Reproductive traits that require high parental or energetic investment were favoured in low‐predation treatments at both low‐latitude regions. In summary, predation had a stronger influence on trait responses of prey communities at lower latitudes where biotic interactions are expected to be more intense, but changes in functional diversity and structure hinged on co‐occurrence histories of local predators with native or introduced prey. This study provides one of the first examinations of the effects of predation on functional trait responses of prey communities across a latitudinal gradient.

Biotic interactions shape trait assembly of marine communities across time and latitude

“…Prior to analysis, we Table 1. List of traits considered in this study with their surrogate function and corresponding reference, as published in [5].…”

Effect of habitat topography on the structure and diversity of benthic communities across five marinas from the southwestern Atlantic Ocean

“…Furthermore, some of these species were never observed in complex substrates in some sites. We then suggest that the complexity of substrates as manipulated here, by providing protruding structures, is probably associated with the creation of refuges against predation for fragile prey from the subtidal zone, which can cover and suffocate calcified organisms like barnacles, changing the relative abundance of species based on species palatability traits (López & Freestone, 2021). These results are similar to other studies that manipulated habitat complexity through the addition of crevices and holes (Bulleri & Chapman, 2010; Strain et al, 2021; Strain, Olabarria, et al, 2018) suggesting that both crevices as protruding structures can result in refuges for organisms susceptible to predation.…”

From Plates to Baits: Using a Remote Video Foraging System to Study the Impact of Foraging on Fouling Non-Indigenous Species

“…Invasive species also often have traits that favour competition against native species and/or provide enhanced defences against predators, i.e., [11,12,15,16]. Some NIS with invasive traits have allelochemical defences such as toxins and non-palatable compounds that grant them a repulsive smell or taste [17][18][19], often granting them ecological advantages towards native taxa. In such cases, native consumers (predators and grazers) often reject feeding on NIS and selectively target a native-based diet.…”