Changing interactions among persistent species as the major driver of seasonal turnover in plant-caterpillar interactions

Abstract

β diversity of herbivorous insects in the tropics is usually very high, and there is often strong dissimilarity in herbivore species composition across different spatial scales and different abiotic gradients. Similarly, turnover is high for trophic interactions between herbivorous insects and their host plants. Two factors have been proposed to explain temporal or spatial differences in trophic interactions: changes in species composition and temporal changes in the behavior of shared species. The goal of this study was to evaluate determinants of high β diversity of trophic interactions between lepidopteran caterpillars and their host plants across dry and rainy seasons and their transitions. Over the course of a year, interaction diversity data were collected from 275 temporary plots in Cerrado vegetation, comprising 257 species of caterpillars, 137 species of host plants and 503 different trophic interactions. All these diversity parameters varied across seasons. Species assemblages of caterpillars and plants were different among the four seasons, and there was a high turnover of interactions between the seasons. The high temporal β diversity of trophic interactions was mostly due to interaction rewiring between co-occurring species, as opposed to changes in species composition over time.

Scale dependent patterns in interaction diversity maintain resiliency in a frequently disturbed ecosystem

“…high response diversity), and that this functional redundancy is greatest when levels of beta interaction diversity (for multiple scales) are maintained (Figure 1). Higher levels of turnover in interactions are indicative of increased ecological function (Lepesqueur et al 2018) such that a reduction in beta diversity represents a homogenization of interactions which may reduce ecosystem function by affecting productivity, resilience to disturbance, and vulnerability to biological invasion (Balata et al 2007, Dell et al 2019). As frequent fire maintains high-levels of plant diversity and ecosystem function, we predict that large-scale interaction diversity will be higher in frequently burned stands than in stands with longer times since fire.…”

Importance of interaction rewiring in determining spatial and temporal turnover of tritrophic (Piper‐caterpillar‐parasitoid) metanetworks in the Yucatán Península, México

“…Overall, interaction turnover across sites and seasons exhibited high values and less variable dissimilarity (β wn = 0.87-0.95) compared to species turnover (β s = 0.59-0.99), which reflects the prevalence of interaction rewiring across space and time. A high degree of interaction turnover is common among interaction networks, and similar magnitudes and ranges have been reported primarily for mutualistic, but also antagonistic networks, across spatial (Carstensen et al, 2014;Kemp et al, 2017), temporal (CaraDonna et al, 2017Lepesqueur et al, 2018;Olesen et al, 2011), and land-use gradients (Morrison & Dirzo, 2020). Interaction turnover in plant-herbivore networks has mixed results, Kemp et al (2017) showed that species composition influenced interaction turnover across spatial gradients, while Lepesqueur et al (2018) showed that interaction rewiring is the primary driver of interaction turnover across seasons.…”

“…Despite the value of documenting variation of insect assemblages on plants, natural history studies describing plant–caterpillar–parasitoid interactions are still relatively uncommon (Dyer et al, 2010). Seasonal turnover in plant–herbivore interactions may be largely influenced by interaction turnover due to reassembly or reorganization of interactions among the same pool of co‐occurring species (i.e., CaraDonna et al, 2017; Lepesqueur et al, 2018; Saavedra et al, 2017), referred hereafter as interaction rewiring , rather than turnover in species composition. Yet, there is much to be explored regarding spatial and seasonal effects on interaction beta diversity and rewiring (Bartley et al, 2019), as well as the contribution of each trophic level to overall structure of metanetworks.…”

Interaction Diversity Maintains Resiliency in a Frequently Disturbed Ecosystem

“…Furthermore, redundant interactions that may be interchangeable can contribute to sustained ecosystem function (Valiente-Banuet et al, 2015). Higher interaction beta diversity and lower species richness suggest redundant interactions via a rewiring of interacting species in frequently burned forests and may confer resiliency by way of maintenance of ecological function (Lepesqueur et al, 2018). This high degree of interaction turnover may provide an advantage to species adapted to frequently disturbed longleaf pine ecosystem.…”

“…We posit that resiliency will be greatest in ecosystems where there is functional redundancy, (i.e., high response diversity), and that this functional redundancy is greatest when levels of beta interaction diversity (for multiple scales) are maintained (Figure 1). Higher levels of turnover in interactions are indicative of increased ecological function (Lepesqueur et al, 2018) such that a reduction in beta diversity represents a homogenization of interactions which may reduce ecosystem function by affecting productivity, resilience to disturbance, and vulnerability to biological invasion (Balata et al, 2007;Dell et al, 2019). As frequent fire maintains high-levels of plant diversity and ecosystem function, we predict that large-scale interaction diversity will be higher in frequently burned stands than in stands with longer times since fire.…”