Data for: Herbivores disrupt the flow of food resources to termites in dryland ecosystems

Irruption of herbivore populations due to the extirpation of predators has
led to dramatic changes in ecosystem functioning worldwide. Herbivores
compete with other species for their primary source of nutrition, plant
biomass. Such competition is typically considered to occur between species
in closely related clades and functional groups but could also occur with
detritivores that consume senescent plant biomass. Here, we test
predictions that herbivores’ indirect impacts on dead vegetation increase
with primary productivity and extend to termites which feed on senescent
vegetation. We compared dead vegetation cover and termite activity in
herbivore exclosures and associated grazed plots at 3 locations situated
along a rainfall gradient in arid Australia where kangaroo populations
have irrupted. Dead vegetation cover and termite activity
increased with rainfall in ungrazed plots but showed a negligible response
to rainfall in grazed plots. Our results suggest that grazing can disrupt
the flow of energy to detritivores and decouple the relationship between
termite activity and primary productivity. Such disruption could have
far-reaching impacts on arid ecosystems because many organisms sit within
“brown food webs” that are sustained by energy derived from decomposition
of senescent plant-tissues.