Nonnative species disrupt ecosystems by
a. increasing biodiversity
b. preventing the spread of disease
c. disrupting food chains
d. increasing the populations of native species

Nonnative species disrupt ecosystems by disrupting food chains. 

Plants take energy from the sunlight with the of chlorophyll so the plant starts the food chain. then an herbivore eats the plant and gets its energy.then a carnivore or a human eats the herbivore and gets its energy. : )