Panel 2

Panel 2 – What Happened to Our Forests?

Humans Happened!

Panel 2In Panel 2, What Happened to Our Forests, you’ll learn how humans have changed our forests.


Poor grazing practices by early sheep and cattle ranchers greatly reduced the amount of native grasses, breaking the cycle of frequent, low-intensity fires. Reduced competition from native grasses allowed pine seedings to grow in thick patches.



Past logging activities removed large, fire resistant trees and left understory brush, small trees, and logging waste to fuel large fires.

Fire Suppresion

Fire suppresion allowed thick seedling patches to grow into dense stands of small trees, known as dog-hair thickets, which led to an accumulation of flammable forest debris.

The Result: A Decline in Forest Health

Arizona’s forests have been overwhelmed by the growth of small trees that would have been removed by fire. The once prevalent openings have been nearly eliminated. Trees compete for water, light, and nutrients, which makes them susceptible to the effects of drought, insects, disease, and wildfire.




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