Phylogenetic trophic specialization: a robust comparison of herbivorous guilds

Author(s)

Jorge, Leonardo R. ^[1] ; Novotny, Vojtech ^{[2, 3, 4]} ; Segar, Simon T. ^{[2, 3, 4]} ; Weiblen, George D. ^{[5, 6]} ; Miller, Scott E. ^[7] ; Basset, Yves ^{[7, 2, 3, 4, 8]} ; Lewinsohn, Thomas M. ^[1]

Affiliation

^[1] Univ Estadual Campinas, Biol Inst, Anim Biol Dept, BR-13083970 Campinas, SP - Brazil

^[2] Czech Acad Sci, Biol Ctr, Branisovska 31, Ceske Budejovice 37005 - Czech Republic

^[3] Univ South Bohemia, Fac Sci, Branisovska 31, Ceske Budejovice 37005 - Czech Republic

^[4] Inst Entomol, Branisovska 31, Ceske Budejovice 37005 - Czech Republic

^[5] Univ Minnesota, Bell Museum, 1479 Gortner Ave, St Paul, MN 55108 - USA

^[6] Univ Minnesota, Dept Plant Biol, 1479 Gortner Ave, St Paul, MN 55108 - USA

^[7] Smithsonian Trop Res Inst, Apartado 0843-03092, Panama City - Panama

^[8] Univ Panama, Maestria Entomol, Panama City 080814 - Panama

• Document type: Journal article
• Source: Oecologia; v. 185, n. 4, p. 551-559, DEC 2017.
• Web of Science Citations: 3

Abstract

Resource specialization is a key concept in ecology, but it is unexpectedly difficult to parameterize. Differences in resource availability, sampling effort and abundances preclude comparisons of incompletely sampled biotic interaction webs. Here, we extend the distance-based specialization index (DSI) that measures trophic specialization by taking resource phylogenetic relatedness and availability into account into a rescaled version, DSI{*}. It is a versatile metric of specialization that expands considerably the scope and applicability, hence the usefulness, of DSI. The new metric also accounts for differences in abundance and sampling effort of consumers, which enables robust comparisons among distinct guilds of consumers. It also provides an abundance threshold for the reliability of the metric for rare species, a very desirable property given the difficulty of assessing any aspect of rare species accurately. We apply DSI{*} to an extensive dataset on interactions between insect herbivores from four folivorous guilds and their host plants in Papua New Guinean rainforests. We demonstrate that DSI{*}, contrary to the original DSI, is largely independent of sample size and weakly and non-linearly related with several host specificity measures that do not adjust for plant phylogeny. Thus, DSI{*} provides further insights into host specificity patterns; moreover, it is robust to the number and phylogenetic diversity of plant species selected to be sampled for herbivores. DSI{*} can be used for a broad range of comparisons of distinct feeding guilds, geographical locations and ecological conditions. This is a key advance in elucidating the interaction structure and evolution of highly diversified systems. (AU)

• FAPESP's process: 14/16082-9 - Diversification and trophic specialization in phytophagous insects
• Grantee: Leonardo Ré Jorge
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/16006-0 - New approaches to host specificity analysis in the communities of tropical herbivores
• Grantee: Thomas Michael Lewinsohn
• Support Opportunities: Research Grants - Visiting Researcher Grant - International