Synthesis of the conservation value of the early-successional stage of succession in eastern U.S. forests

Background/Question/Methods

Early-successional species require conditions and resources present in recently disturbed sites, however these conditions are ephemeral and change rapidly over time as the site becomes dominated by later seral species. Natural disturbance regimes such as wind-throw, fire and flooding have been altered or suppressed in eastern forests through human activity such as conversion of forests to younger ages stands more resistant to wind, fire suppression and mesophycation of fire-adapted communities, and suppression of beaver activity. Furthermore, the influence of anthropogenic disturbances has changed over much of the region to systems that provide fewer of the conditions characteristic of early-successional communities. As a result of these changes the extent of early-successional communities across most of the region is arguably near historic lows, as are the species that depend on them, causing many scientists to identify the conservation of early-successional species as a high priority. These species make a disproportional contribution to state and federal lists of special concern and many are the subject of regional conservation plans.

Results/Conclusions

Despite the preponderance of scientific evidence in support of this concern, there is still skepticism on the part of some non-specialists about the role of disturbance in maintaining biodiversity and the means, if any, by which this should be accomplished, and public opposition remains a challenge to conserving these communities. Contemporary approaches use natural disturbance regimes to inform management practices that employ historical agents where possible or surrogates when necessary to achieve desired future conditions defined on the basis of regional population or community status. In some cases these conservation activities can be coordinated with commercial activities like silviculture or maintenance of infrastructure (e.g. powerline corridors), however our work indicates deliberate efforts expressly directed at conservation of early-successional communities are more effective. Conservation of early-successional communities occurs within the context of other potentially conflicting ecological values, such as the conservation and enhancement of biologically mature forest, however recent findings show early-successional communities can augment diversity in forested landscapes by providing resources for mature forest species, such as food or predator free space for juvenile forest songbirds that seek out early-successional habitats during the transition to independence. Balancing the conservation of early-successional communities with these other sometimes conflicting values is an active area of current conservation research.