Question

what role do plants play in a ecosystem

Answer 1

the role of plants ina ecosystem is 1.they are the primary producers of food

Answer 2

plants have autotrophic mode of nutrition unlike humans and animals. So basically, we are all dependent on plants for food. Also, plants absorb energy from sun which is transferred to next trophic level. Thus, plants is also basic source of energy to food web.

Hope it helps :)