Change in disturbance regimes -- rather than a change in climate -- is largely responsible for altering the composition of Eastern forests, according to a researcher. Forests in the Eastern United States remain in a state of "disequilibrium" stemming from the clear-cutting and large-scale burning that occurred in the late 1800s and early 1900s, he contends.
Marc Abrams, professor of forest ecology and physiology.Moreover, Abrams noted, since about 1930 -- during the Smokey Bear era -- aggressive forest-fire suppression has had a far greater influence on shifts in dominant tree species than minor differences in temperature.
"To the north, intensive and expansive early European disturbance resulted in the ubiquitous loss of conifers and large increases of Acer (maple), Populus (poplar) and Quercus (oak) in northern hardwoods, whereas to the south, these disturbances perpetuated the dominance of oak in central hardwoods."Fire suppression has resulted in more sugar maples and in denser, cooler forests.