Biodiversity in forests is important for healthy ecosystems and food chains, but human activities like pollution are reducing biodiversity and harming forests. Biodiversity allows all groups of plants and animals to interact as producers, primary consumers, secondary consumers and decomposers. When humans living near forests pollute the air with car fumes and factory waste, it kills many plants and disrupts the food chain, eventually destroying the whole forest. The loss of deciduous forests affects humans by eliminating sources of wood and food.