Disturbance and early succession in the southern Appalachians and the eastern U.S

Background/Question/Methods

Disturbances beyond a threshold of intensity or frequency can initiate or maintain early successional vegetation.  Throughout the southern Appalachian mountains and more broadly the eastern U.S., disturbances, including fire, wind storms, and landslides, interweave with complex topography and vegetation history to produce a tapestry of plant community types and ages.  We synthesized the literature within the context of functional disturbance attributes, such as canopy-down vs. soil-up extent, and plant responses, such as regeneration mode, to investigate the contribution of disturbance to early succession.

Results/Conclusions

As expected from climate patterns, fires and hurricanes are the most common disturbances toward the south in the eastern U.S., while tornadoes and ice storms increase toward the west and north; landslides and wind predominate in the southern Appalachians.  Singly and in combinations, these disturbances create or sustain early successional habitat; however, today’s forests, which are recovering from wide-scale logging of the early 20^th century, are likely to be younger than the return interval of stand-replacing events.  The future distribution of early successional habitat may be most abundant when natural disturbances are followed by forest management.