Authors: William Flatley*, University of Central Arkansas, Cathleen McNutt, University of Central Arkansas, Alexander Russell, University of Central Arkansas, Lillian McDaniel, University of Central Arkansas
Topics: Biogeography, Paleoenvironmental Change, Physical Geography
Keywords: fire history, Ozark Mountains, dendrochronology, vegetation dynamics, tree invasion
Session Type: Poster
Presentation File: No File Uploaded
Glades are relatively open habitats distributed throughout the Ozark Mountains, providing habitat for numerous rare and endangered species. However, many glades have been altered by the invasion of eastern red cedars (Juniperus virginiana). Fire exclusion during the 20th century may have contributed to tree invasion at these sites. In order to test this hypothesis, we reconstructed fire history and are currently characterizing age structure of the invading cedars at Devil’s Knob-Devil’s Backbone Natural Area, a complex of limestone, dolomite and sandstone glades surrounded by shortleaf pine-oak-hickory woodlands. The fire history reconstruction provides evidence of frequent wildfires (mean fire return intervals of 2.0 – 9.2 years) in the woodlands surrounding the glades during the 18th and 19th century. Fires were less frequent during the 20th century. To assess the influence of fire on tree invasion of the glade habitat we cored a stratified random sample of trees within the bald habitat to determine whether tree establishment aligned with the decline in fire frequency. Dating of the cores is ongoing, with the objective of answering the following questions: 1) Does the initiation of cedar invasion align with reductions in fire frequency on the surrounding slopes? 2) Are there pockets of older cedars or other trees that predate the decline of fire? 3) Are differences in the timing of tree invasion related to variability in soil properties, topography, or distance to the edge of the knob? Characterization of tree invasion dynamics will help guide restoration of the glade community at the site.