Multi-millennial record of erosion and fires in the southern Blue Ridge Mountains, USA In: Greenberg, CH and BS Collins (eds.)
Abstract
Bottomland sediments from the southern Blue Ridge Mountains provide a coarse-resolution, multi-millennial stratigraphic record of past regional forest disturbance (soil erosion). This record is represented by 12 separate vertical accretion stratigraphic profi les that have been dated by radiocarbon, luminescence, cesium-137, and correlation methods continuously spanning the past 3,000 years of pre-settlement (pre-dating widespread European American settlement) and postsettlement strata. Post-settlement vertical accretion began in the late 1800s, appears to be about an order of magnitude faster than pre-settlement rates, and is attributable to widespread deforestation for timber harvest, farming, housing development, and other erosive activities of people. Natural, climate-driven, or non-anthropic forest disturbance is subtle and diffi cult to recognize in pre-settlement deposits. There is no indication that pre-settlement Mississippian and Cherokee agricultural activities accelerated erosion and sedimentation in the region. A continuous 11,244 years before present (BP) vertical accretion record from a meander scar in the Upper Little Tennessee River valley indicates abundant charcoal (prevalent fi res) at the very beginning of the Holocene (11,244–10,900 years BP). In contrast, moderate to very low levels of charcoal are apparent over the remaining Holocene until about 2,400 years BP when charcoal infl ux registers a pronounced increase. These data are consistent with the idea that Native Americans used fi re extensively to manage forests and to expanded agricultural activities during Woodland and later cultural periods over the past 3000 years. However, there is no indication that prehistoric intentional use of fi re and agriculture caused accelerated erosion and sedimentation.