Eastern US forests more vulnerable to drought than before 1800s University Park PA (SPX) Mar 10, 2016 - Over thousands of years, most forests in the eastern United States evolved with frequent fire, which promoted tree species and ecosystems that were both fire and drought resistant. In little more than a century, humans upset that balance, suggest researchers, who blame the change, in part, on the well-meaning efforts of Smokey Bear. Since the 1930s, the composition of forests in the region ... more

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