The effects of treatment and management history on the control of Old World climbing fern (Lygodium microphyllum), Brazilian pepper (Schinus terebinthifolia), and punktree (Melaleuca quinquenervia)

Abstract

To successfully reduce overall invasive plant cover over time, an effective treatment plan must be established such that mortality exceeds new colonization and re-spouting growth rates. However, few evaluations of the effects of long-term, consistent treatment at different intervals exist. We report the effects of treatment intensity on Old World climbing fern (Lygodium microphyllum (Cav.) R. Br.), Brazilian pepper (Schinus terebinthifolia Raddi) and punktree (Melaleuca quinquenervia (Cav.) S. T. Blake), as part of a large restoration project that has been underway for six years in Telegraph Swamp at Babcock Ranch Preserve, a 68,000 acre conservation area in Florida, U.S.A. We found that at the end of the six-year period, for all three species, average live cover did not exceed 5% across all transects. In addition, dead foliar cover was higher than live cover for all three invasive plants, indicating progress towards restoration goals. We also found that percent live cover of Old World climbing fern were significantly reduced only after four or more treatments were applied during the six-year period, as opposed to when three or fewer treatments were applied. Reductions in percent cover of live foliage were apparent only when the treatments were applied more often than biennially, as opposed to less often than biennially. Additionally, we found higher Old World climbing fern cover in clear-cut and replanted cypress stands than in natural stands. Based on these findings, we conclude that treatments applied four or more times, or more often than biennially, were more effective at significantly reducing advanced invasions of Old World climbing fern, Brazilian pepper, and punktree, especially where previous management activities or their effects may have increased the cover of invasive plants.

Fire and Invasive Plant Interactions

“…Studies have also shown that herbicide treatment after fire greatly reduces climbing fern coverage (Hutchinson 2010;Stocker et al 2008). Finally, recent field research has indicated that a treatment return interval of less than two years is needed to reduce Old World climbing fern (Dietz et al 2020).…”