Control of cabbage palms in William Beardall Tosohatchee WMA

The Cabbage Palm Flatwoods is recognized by the Florida Natural Areas Inventory as a variant of the wet flatwoods plant community, where cabbage palm (Sabal palmetto) is the dominant plant in the understory, and limestone or calcareous substrates are present near the soil surface.  FWC staff made comparisons of recent and historical aerial photographs showing that numerous cabbage palm flatwood sites in Florida have been encroached by cabbage palms over the last 6 decades, and FWC land managers have observed an associated lack of herbaceous understory on heavily palm-encroached sites such as William Beardall Tosohatchee WMA. Altered hydrology and/or fire suppression are the likely causes of cabbage palm encroachment.

During periods of fire suppression, cabbage palms build large stores of belowground carbohydrates, which allow established plants to resprout vigorously following fire. Reversing fire suppression in cabbage palm flatwoods will likely require mechanical thinning and/or herbicide treatments in addition to reintroduction of a frequent prescribed fire regime. In this project, we applied four experimental treatments to cabbage palm-encroached flatwoods:  1) Clear Cut (100% palm removal), 2) Thinning (50% palm removal), 3) Herbicide (15% triclopyr application), and 4) Control (no treatment). We are monitoring cabbage palm regeneration and understory vegetation response for three years following treatment, in order to determine whether any of the tested treatments are effective for controlling cabbage palm encroachment and promoting herbaceous understory regeneration.