Eutrophication, biodiversity loss, and species invasions modify the relationship between host and parasite richness during host community assembly. (26th June 2020)

• Record Type: Journal Article
• Authors: Halliday, Fletcher W.; Heckman, Robert W.; Wilfahrt, Peter A.; Mitchell, Charles E.
• Is Part Of: Global change biology. Volume 26:Number 9(2020)
• Page Start: 4854
• Page End: 4867
• Publication Date: 2020-06-26
• Subjects: biodiversity loss -- community assembly -- diversity–disease -- eutrophication -- invasive species -- old fields -- parasite diversity -- phylogenetic diversity; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.15165
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: Host and parasite richness are generally positively correlated, but the stability of this relationship in response to global change remains poorly understood. Rapidly changing biotic and abiotic conditions can alter host community assembly, which in turn, can alter parasite transmission. Consequently, if the relationship between host and parasite richness is sensitive to parasite transmission, then changes in host composition under various global change scenarios could strengthen or weaken the relationship between host and parasite richness. To test the hypothesis that host community assembly can alter the relationship between host and parasite richness in response to global change, we experimentally crossed host diversity (biodiversity loss) and resource supply to hosts (eutrophication), then allowed communities to assemble. As previously shown, initial host diversity and resource supply determined the trajectory of host community assembly, altering post‐assembly host species richness, richness‐independent host phylogenetic diversity, and colonization by exotic host species. Overall, host richness predicted parasite richness, and as predicted, this effect was moderated by exotic abundance—communities dominated by exotic species exhibited a stronger positive relationship between post‐assembly host and parasite richness. Ultimately, these results suggest that, by modulating parasite transmission, community assembly can modify the relationship between host and parasite richness. These results thus provide a novel mechanism to explain how global environmental change can generate contingencies in a fundamental ecological relationship—the positive relationship between host and parasite richness. Abstract : Host and parasite richness are often positively correlated, but the stability of this relationship in response to global change remains poorly understood, in large part because the effects of global change drivers manifest over time. In a field experiment, we show that, over time, eutrophication and biodiversity loss can alter the relationship between host and parasite richness by driving host community assembly. Host community assembly was implicated in modulating parasite transmission, providing a novel mechanism to explain how global change can generate contingencies in a fundamental ecological relationship: the positive relationship between host and parasite richness.