Fact 1: Planting trees has a positive impact on an ecosystem.

Fact 2: Destruction of Trees is taking place, pollution of air is the Result of cutting trees with pace.

Given the two facts above, answer the question "What has a positive effect on an ecosystem?" with the following options: 
- maintaining air pollution
 - removing habitats
 - stopping air pollution
 - to stay warm
 - in the frog family
 - Electric generators
 - increasing air pollution
 - genetic diversity


 

   stopping air pollution      