Data from: Diversity and composition of viral communities: coinfection of barley and cereal yellow dwarf viruses in California grasslands 2000 - 2005

Most species host multiple pathogens, yet field studies rarely examine
the processes determining pathogen diversity within a single host or
the effects of coinfection on pathogen dynamics in natural systems.
Coinfection can affect pathogen transmission and virulence. In turn,
coinfection can be regulated within hosts by interactions such as
cross-protective immunity or at broader spatial scales via vector
distributions. Using a general model, we demonstrate that coinfection
by a group of vectored pathogens is highest with abundant generalist
vectors and weak cross-protection and coinfection- induced mortality.
Using these predictions, we investigate the distribution of five
coexisting aphid-vectored, viral pathogens (barley and cereal yellow
dwarf luteoviruses and poleroviruses) in a native perennial grass
(Elymus glaucus) in both space (700 km) and time (4 years). Observed
coinfection rates were much higher than expected at random, suggesting
that within-host processes exerted weak effects on within-host
pathogen diversity. Covariance among viruses in space and time was
highest for viral species sharing a vector. Temporal correlation arose
from the synchronous invasion of two viruses transmitted by a shared
aphid species. On the basis of our modeling and empirical results, we
expect that factors external to individual hosts may affect the
coinfection dynamics in other communities hosting vectored pathogens.