Fact 1: Cutting down trees has a negative impact on an ecosystem.

Fact 2: Black spruce is the dominant tree species.

Given the two facts above, answer the question "what has a negative impact on the ecosystem when cut down?" with the following options: 
- humans disturb it
 - scarce resources
 - Smoking
 - disease
 - black spruce
 - swamp vegetation
 - deforestation
 - Pesticides


 

     black spruce    