Kill off a species of animals.
Extinctions.
because it would change all the system in a food chain
In a deciduous forest, the top predator in the food chain might be a large carnivore such as a wolf or a bear. These predators feed on smaller animals such as deer, rabbits, and birds that occupy lower trophic levels in the food chain.
Your question is unclear but people are at the top of the food chain.
it makes it a food chain
people
The food chain gets broken every time a creature goes extinct.
eagle
People like to think of themselves are being at the top of the food chain, and that is true if you are looking only at large animals. However, the food chain is more properly considered as a circle or cycle and people are fed upon by numerous bacteria, fungus, insects and other smaller creatures. So, in that larger sense, people are not at the mythical top of a food chain.
Mostly plants. Meat would be higher up the food chain.
Plants are at the Begining
it is on the top of the food chain,but people kill them to get food