Critical slowing down in cone production of longleaf pine trees
Longleaf pine forests were historically distributed throughout the southeastern United States and played an important role in local sectors of society, economy, and ecology. The longleaf pine became an endangered ecosystem due to over-harvesting, broad land-use change, and fire suppression. One major factor that has challenged restoration efforts is sporadic seed production. Based on collected cone production data in the past six decades, we tested whether critical slowing down existed in cone production at three longleaf pine locations. Our results indicated decreased variance and increased autocorrelation in variance before a high cone production. Theseresults provide a new understanding of cone production from the perspective of a dynamic system. This method may be helpful in predicting years of favorable cone production for forest management.