Assertion: fire ant's impact | /r/HasAspect | positive effect
Facets:
value: at low levels
type: OTHER
value: on animal groups
type: TRANSITIVE-OBJECT
Source sentences:
text: Dr Frank van Veen, another author on the study, said: "What we find is that the impact of ants on soil nutrient levels has a positive effect on animal groups at low levels, but as the number of ants increases, their predatory impacts have the bigger effect -- thereby counteracting the positive influence via ecosystem engineering.