The role of Native American fire regimes in the maintenance of longleaf pine savanna.
详细信息
文摘
The longleaf pine savanna of the southeastern United States has been declining in areal extent during the past 300 years. Many factors contribute to this decline,including timber harvesting,land clearance and conversion. However,frequent surface fires are recognized as a primary factor in maintaining longleaf pine dominance. Missionary accounts from 16th century document that pre-Columbian populations in the southeast region used fire for agricultural and hunting purposes,suggesting that longleaf pine savannas were maintained by human-set fires. Regional Native American populations declined and societies collapsed during the 16th Century after introduction of diseases and military assaults by the deSoto Expedition and other European parties. If Native American cultural practices were responsible for maintaining the longleaf pine ecosystem,reduction of fires in the 16th and 17th Centuries should have led to invasion of longleaf pine stands by oaks and slash pines and conversion from savanna to forest. I am testing this hypothesis by examining paleoecological records from three lakes in the Florida longleaf pine ecosystem. Here I present results from paleoecological results obtained from three lake sediment cores spanning the last 1000 years,one in north-central Florida Sheelar Lake),one in central Florida Ledas Pond) and another in the Florida Peninsula Silver Lake). Little paleoecological evidence is found supporting the hypothesis that cultural disruption from the deSoto Expedition resulted in vegetation composition or fire regime change. However,data do indicate large scale regional change during European settlement and modern land use 1760-present) can be found in the paleoecological record. Results of this project bring to light issues with long held assumptions both methodological and philosophical) in the fields of paleoecology and anthropology and challenge researchers to reconsider conducting studies using only traditional approaches.