Data from: Habitat quality influences pollinator pathogen prevalence through both habitat–disease and biodiversity–disease pathways

The dilution effect hypothesis posits that increasing biodiversity reduces
infectious disease transmission. Here, we propose that habitat quality
might modulate this negative biodiversity–disease relationship. Habitat
may influence pathogen prevalence directly by affecting host traits like
nutrition and immune response (we coined this as the ‘habitat–disease
relationship’) or indirectly by changing host biodiversity
(biodiversity–disease relationship). We used a path model to test the
relative strength of links between habitat, biodiversity, and pathogen
prevalence in a pollinator–virus system. High-quality habitat metrics were
directly associated with viral prevalence, providing evidence for a
habitat–disease relationship. However, the strength and direction of
specific habitat effects on viral prevalence varied based on the
characteristics of the habitat, host, and pathogen. In general, more
natural area and richness of landcover types were directly associated with
increased viral prevalence, while greater floral density was associated
with reduced viral prevalence. More natural habitat was also indirectly
associated with reduced prevalence of two key viruses (black queen cell
virus and deformed wing virus) via increased pollinator species richness,
providing evidence for a habitat-mediated dilution effect on viral
prevalence. Biodiversity–disease relationships varied across viruses, as
prevalence of sacbrood virus was not associated with any habitat quality
or pollinator community metrics. Across all viruses and hosts,
habitat–disease and biodiversity–disease paths had effects of similar
magnitude on viral prevalence. Therefore, habitat quality is a key driver
of variation in pathogen prevalence among communities via both direct
habitat–disease and indirect biodiversity–disease pathways, though the
specific patterns varied among different viruses and host species.
Critically, habitat–disease relationships could either contribute to or
obscure dilution effects in natural systems depending on the relative
strength and direction of the habitat–disease and biodiversity–disease
pathways in that host–pathogen system. Therefore, habitat may be an
important driver in the complex interactions between hosts and pathogens.