Recovery and Restoration of Disturbed Sand Bars of the Apalachicola River, Florida

Abstract

abstract: Large, low-lying rivers have a variety of societal uses and show a wide range of disturbances. One such example, the Apalachicola River in the Florida Panhandle, experienced anthropogenic activities that altered its hydrologic, geomorphic, and ecologic condition. The river's sand bars enlarged more than threefold in area because of dredge disposal and localized incision from anthropogenic activities during a navigation project. Once dredging ended, the river experienced passive recovery through the slow regrowth of riparian vegetation, with sand bars reducing in area ~18% from 2005 to 2015. The outcomes of tree-line change analyses from 1999 to 2019 indicate a higher recovery rate in the first decade (1999-2010), migrating fastest in locations where vegetation islands stabilize sediments. To help accelerate vegetation regrowth, during the growing seasons of 2018 and 2019, we planted willow stakes at various positions and microhabitats covering ~3.6 ha of three enlarged sand bars near Blountstown, FL. Our mapping shows some synergies between passive recovery and active restoration as tree-line expansion had the fastest rates between 2019 and 2021. Our study gives insights and guidance into passive recovery and restoration projects involving plantings on large, low-lying rivers.