Virus infections in 27 Plantago lanceolata populations in the Åland Islands in 2015

Human alteration of natural habitats may change the processes governing
species interactions in wild communities. Wild populations are
increasingly impacted by agricultural intensification, yet it is unknown
whether this alters biodiversity mediation of disease dynamics. We
investigated the association between plant diversity (species richness,
diversity) and infection risk (virus richness, prevalence) in populations
of Plantago lanceolata in natural landscapes as well as those occurring at
the edges of cultivated fields. Altogether 27 P. lanceolata populations
were surveyed for population characteristics and sampled for PCR detection
of five recently characterized viruses. We find that plant species
richness and diversity correlated negatively with virus infection
prevalence. Virus species richness declined with increasing plant
diversity and richness in natural populations while in agricultural edge
populations’ species richness was moderately higher, and not associated
with plant richness. This difference was not explained by changes in host
richness between these two habitats, suggesting potential pathogen
spill-over and increased transmission of viruses across the
agro-ecological interface. Host population connectivity significantly
decreased virus infection prevalence. We conclude that human use of
landscapes may change the ecological laws by which natural communities are
formed with far reaching implications for ecosystem functioning and
disease.