Answer:
It allowed too few fires to burn in forests.
Step-by-step explanation:
Before the Smokey Bear campaign began, tree observers and fire historians can observe that fires used to occur every 10 years or so and they would leave a small scar on trees, but would not kill the tree itself. When the campaign got underway, its objective was to stamp out all types of fires. As a result, more and more trees came up and grew in forests, which has now resulted in having more ¨fuel¨ for forest fires with more trees available to burn, which has then resulted in bigger and more dangerous wildfires going out of control. This is what researchers are finding as a damage to forest health.