The use of glyphosate for Carpobrotus eradication in sand dune ecosystems: evaluation of the potential effects on the reintroduction of native plants

<i>Carpobrotus</i> Management in a Mediterranean Sand Dune Ecosystem: Minimum Effective Glyphosate Dose and an Evaluation of Tarping

“…Moreover, in the summer of 2008, 11 different native plant species and 3 invasive species were observed on these experimental plots (Table 1). Thus, as previously reported (Walker et al 2016;Fos et al 2021), the conducted observations indicated that targeted glyphosate spraying effectively controlled invasive species without adversely affecting the surrounding vegetation.…”

“…Nonetheless, it has been shown that context and scale must be considered when applying bans on the small-scale use of glyphosate, such as for the purposes of invasive plant control (Pergl et al 2020). Indeed, given the effectiveness of this herbicide and its lower economic cost compared to mechanical plant removal methods (Fos et al 2021); it is being increasingly used in invasive plant control and eradication campaigns. Indeed, in addition to its use for controlling Carpobrotus (Lazzaro et al It should also be noted that the emergence of native species was observed after glyphosate spraying, with at least 11 species being identified in the set of experimental plots (Table 1).…”

“…In addition to glyphosate, at least five other herbicides or formulations have been shown to be effective in the eradication of Carpobrotus, (1) paraquat plus simazine and benzoylprop-ethyl (Guerreiro, 1977) Glyphosate has been shown to be effective for Carpobrotus eradication when sprayed at concentrations of 3.6 and 5.4 kg/ha (Guerreiro, 1977), 2.9 to 3.1 kg/ha (Hueso et al 2005), 4.0 kg/ha (Smyth et al 2011), or of 3.6 kg/ha (Lazzaro et al 2020). This compound was also highly effective when sprayed on experimental plots at 40 kg/ha-around 10 times the maximum recommended dose range (EFSA 2017)-in a study evaluating the effects of residual glyphosate on the restoration of natural vegetation by sowing (Fos et al 2021). However, to date, no studies have examined the minimum effective dose required for the eradication of Carpobrotus.…”

Demographic analysis of an Israeli Carpobrotus population

“…Leaving litter increases the risk Carpobrotus germination from seed and slows recovery of native plants, but decreases the problem of erosion, which is an important issue in sites with steep slopes [13,23,25]. Effective mortality of Carpobrotus and rapid recovery of native vegetation has also been demonstrated with chemical control using Glyphosate [18,24]. At our Havatselet site, both of these methods would be challenging due to the presence of large ramets on the face of the cliff.…”

“…Carpobrotus individuals compete directly with native plants for space, water, and nutrients [14,15], and indirectly by changing the soil pH [9], salt content, moisture level, nutrient content and microbial activity [8]. Carpobrotus litter disrupts natural soil nutrient cycles, increasing nitrogen and organic matter content and releasing allelochemicals that hinder seed germination, seedling emergence and root growth of some native plants [16][17][18]. Carpobrotus populations form mats that prevent sand movement and disrupt normal dune processes of disturbance and succession [9,19,20].…”