Forest change on a steep mountain gradient after extended fire exclusion: San Francisco Peaks, Arizona, USA
The authors compared current forest vegetation structure and composition across an elevational gradient to a dendrochronological reconstruction of vegetation from 1876 to understand the effects of forest management, specifically fire exclusion.
All forest types were significantly less dense in 1876 compared to 2000; however, the changes were less apparent in the higher altitude forests. The authors observed a shift in composition toward more mesic species in lower altitude forests. They suggest that because fire frequencies are typically longer in higher altitude forests, the impact of fire exclusion was not as great as low altitude forests where frequent fire thinned encroaching fire-susceptible mesic species.