Data from: A multivariate test of disease risk reveals conditions leading to disease amplification

Theory predicts that increasing biodiversity will dilute the risk of infectious diseases under certain conditions and will amplify disease risk under others. Yet, few empirical studies demonstrate amplification. This contrast may occur because few studies have considered the multivariate nature of disease risk, which includes richness and abundance of parasites with different transmission modes. By combining a multivariate statistical model developed for biodiversity–ecosystem–multifunctionality with an extensive field manipulation of host (plant) richness, composition and resource supply to hosts, we reveal that (i) host richness alone could not explain most changes in disease risk, and (ii) shifting host composition allowed disease amplification, depending on parasite transmission mode. Specifically, as predicted from theory, the effect of host diversity on parasite abundance differed for microbes (more density-dependent transmission) and insects (more frequency-dependent transmission). Host diversity did not influence microbial parasite abundance, but nearly doubled insect parasite abundance, and this amplification effect was attributable to variation in host composition. Parasite richness was reduced by resource addition, but only in species-rich host communities. Overall, this study demonstrates that multiple drivers, related to both host community and parasite characteristics, can influence disease risk. Furthermore, it provides a framework for evaluating multivariate disease risk in other systems.DRE Disease DataThis file includes data used to asses parasite richness and abundance responses to experimental host resource supply and host diversity treatments. The columns from left to right are: the unique plot ID, the experimental block, the plot planting treatment, the host diversity treatment, the resource supply treatment, community load for all parasites, rarefied parasite richness, microbial parasite load, insect parasite load, microbial rarefied richness, and insect rarefied richness.DRE_Disease_DF.csvDRE Disease AnalysisThis file contains the r code used to assess the impacts of experimental host diversity and resource supply to hosts on parasite abundance and parasite richness.DRE_Disease_Analysis.RFunding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: DEB-101590