Paleoecological Record Of Hurricane Disturbance And Forest Regenerationin Nicaragua

摘要

Studying infrequent phenomena (e.g. hurricanes) and slow processes (e.g. forest regeneration) greatly challenges the ecological techniques of real-time studies. By combining the two relatively new approaches of paleotempestology and fine-resolution palynology, this study provides insight into the impacts of hurricanes and the post-hurricane regeneration of forests. I analyzed a 5-m sediment core from a swamp lagoon on the Caribbean Coast of Nicaragua that covered the entire 8000-yr history of the swamp [Urquhart, G. R., 1997. Disturbance and regeneration of swamp forests in Nicaragua: evidence from Ecology and Paleoecology. Ph.D. Dissertation, The University of Michigan, Ann Arbor, MI, USA]. X-rays revealed a sand layer dating to c. 3300 BP of the type deposited by hurricanes. Pollen analyses showed this sand layer was followed by major changes in vegetation and fires. This pattern is identical to the wake of Hurricane Joan, which struck the area in 1988 and left 90,000 hectares of damaged swamp forest that burned shortly after. After the prehistoric hurricane, forest vegetation did not return until 500 yr later, due to repeated burning. This parallel event of the past illustrates a possible course for modern forest regeneration. As a counterpart to direct ecological analysis, fine-resolution paleoecological study can provide great insight for the study of rare events and slow processes.