Belowground herbivory in red pine stands initiates a cascade that increases abundance of Lyme disease vectors

•We sampled 31 red pine stands to examine the effects of rhizophagy and gap formation.•Stands were either healthy or had pockets of dead and dying trees, symptomatic of red pine pocket decline.•Symptomatic stands had greater ground-level plant biomass and tick population densities.•Nymphal tick infection rates of Lyme disease and anaplasmosis did not differ between stand types.•Stand management can affect human disease risk.