Evaluating the efficacy of removal treatments on wavyleaf basketgrass (Oplismenus undulatifolius)

Abstract

With the spread of a new invasive plant species, it is vital to determine the effectiveness of removal strategies as well as their advantages and disadvantages prior to attempting widespread removal. While thousands of dollars have been spent to curtail the spread of wavyleaf basketgrass (Oplismenus undulatifolius (Ard.) Roem. & Schult.), a relatively new invasive species, the lack of a cohesive management plan and funding has made controlling this species especially difficult. We assessed the efficacy of a variety of chemical control methods and hand-weeding for this species and followed select methods over time. We also assessed the potential for ecosystem recovery following removal by measuring total and native species richness in response to treatments. Our pilot study revealed a wide breadth of responses to our eight herbicides, with fluazifop plus fenoxaprop, imazapic, quizalofop, and sulfometuron methyl being the least effective. In our follow-up experiments, hand-weeding, glyphosate, and clethodim treatments were effective at reducing O. undulatifolius percent cover, density, and biomass, with an average reduction of at least 48% in the first year. However, we found substantial variation in the effectiveness of clethodim between our two experiments, which was likely driven by site differences. We also found that all three of these removal methods were effective at reducing the number of O. undulatifolius flowering stems and the height of those stems, which will likely reduce the spread of this species to new areas. Last, we found that these methods have the potential to restore total and native species richness, but that glyphosate-treated plots did not fully recover until two years after treatment.

Diversity of forest floor vegetation in Napabalano Nature Reserve and Warangga Protection Forest, Southeast Sulawesi

“…3) were found with IVI values of 54.71% and 13.33% (Table 1). These species are invasive species that can spread rapidly (Bowen et al, 2020;Omokhua et al, 2016). The mechanism for spreading several invasive species, such as C. odorata and L. camara, in the Warangga Protected Forest, in general, is with the help of wind, animals, and humans.…”

Seed longevity and germination of the emerging invasive species wavyleaf basketgrass (Oplismenus undulatifolius) under varied light regimes

“…Beauv., Poaceae] is recognized as a high-risk invasive species by the U.S. Department of Agriculture (DCR 2022; USDA 2012). This perennial rhizomatous grass forms dense carpets in the forest understory that may crowd out native herbaceous plants and inhibit the regeneration of native hardwood trees (Beauchamp and Koontz 2013; Bowen et al 2020). Seeds may also be an important form of long-distance dispersal for O. undulatifolius to colonize new habitats.…”