Authors: Jacob Bendix*, Syracuse University, Robert T. Pavlowsky, Missouri State University, Derek J. Martin, Appalachian State University, Toby Dogwiler, Missouri State University
Topics: Biogeography, Geomorphology
Keywords: riparian vegetation, floods, disturbance, Ozarks
Session Type: Paper
Start / End Time: 2:40 PM / 4:20 PM
Room: Napoleon D1, Sheraton 3rd Floor
Presentation File: No File Uploaded
In April 2017, the North Fork River in the Missouri Ozarks experienced an extreme flood, well in excess of the flood of record. We explore the impact of that flood on riparian forest in the North Fork watershed. We sampled 514 living and dead trees within 38 quadrats across the valley floors of five tributaries. Overall, the flood resulted in 12.6% mortality. That figure is skewed by the high survival rate of flexible saplings (only 8.2% mortality), as 25.3% of trees > 5 cm DBH were killed. Impacts varied with landform, with mortality of mature stems ranging from 3.6% on inundated portions of the valley wall to 56.5% on depositional bars. Notably, flood impacts extended well above the channel, with 22.6% mortality on terraces. Small mature trees, lacking both the flexibility of saplings and the strength of larger trees, experienced high mortality, with those 15-20 cm DBH having the highest rate at 44.4%. Differential mortality among species altered the forest composition, with mature stems of blackgum, hornbeam, red cedar, river birch and shortleaf pine all losing more than 30%, while other common species like white ash and black walnut had no losses. Overall, this extreme event did not denude most forested areas, but had a significant impact on the density and composition of the riparian forest, even on landforms typically unaffected by floods.