Typhoon diverged forest succession from natural trajectory in the treeline ecotone of the Changbai Mountains, Northeast China

Abstract

Abstract Windthrow is a typical gap phrase disturbance that changes forest composition but rarely alter succession trajectories of a forest stand. Catastrophic windthrow such as typhoons is a large but infrequent disturbance that can have long-lasting effects on forest ecosystems. Whether catastrophic windthrow resets successional pathways of forest ecosystems remains inconclusive. We compared forest structure and regeneration patterns between undisturbed and disturbed stands 30 years after a typhoon event in the treeline ecotone of the Changbai Mountains, Northeastern China. Measurements were made using WorldView-1 satellite imaging and fieldwork in two types of large plots, one located in areas affected by the typhoon event and the other in adjacent undisturbed areas. Results showed that community divergence at landscape scale occurred following the typhoon. In non-wind–disturbed stands, forest development followed the successional pathway of both broadleaved and coniferous trees. By contrast, the late-successional coniferous rather than the early successional broadleaved trees occupied the wind–disturbed stands. The alteration mechanism on the forest succession pathway was that herbs formed tall, dense, and persistent mono-dominant thickets after the typhoon, which inhibited the regeneration of broadleaved trees. In contrast to the common knowledge that forest would return to initial successional stage after catastrophic disturbance, we concluded that catastrophic windthrow, different from gap phase windthrow, altered forest successional trajectory.