Effects of Glyphosate Application on Physiologically Integrated Clones of the Invasive Plant Carpobrotus edulis

Sergio R Roiloa,Rodolfo Barreiro,Fei-Hai Yu

doi:10.3390/d14010047

Abstract

Management of invasive alien species is a high priority for biodiversity conservation. Here, we studied the effects of glyphosate application, at 0.06 g/m2 concentration, on physiologically integrated basal and apical ramets of the invasive clonal plant Carpobrotus edulis. Physiological integration allows the transport of resources and other substances between connected ramets in clonal plants. We found a significant reduction of growth and photochemical efficiency both in basal and apical ramets of C. edulis after glyphosate application. Interestingly, we also observed a significant growth reduction in untreated basal ramets when they remained connected to apical ramets treated with glyphosate. This result was interpreted as a cost for basal ramets due to supporting severely stressed apical ramets. Therefore, local application of glyphosate to apical ramets of C. edulis can negatively affect not only their own growth, but also the growth of their interconnected, untreated basal ramets. Our results suggest that glyphosate effectiveness can be maintained when applied only to one part of the clone so that the amount of herbicide used in eradication programs can be greatly reduced, which can minimize the negative impact of chemical herbicides on ecosystems.

Highlights

Coastal sand dunes are fragile ecosystems that usually contain both endemic and endangered species, and are a key objective for biodiversity conservation [1]
Connection significantly interacted with glyphosate application to affect root production of basal ramets (Table 1): connection greatly increased root production of basal ramets under no glyphosate, had no significant effect when glyphosate was sprayed to basal ramets and decreased root production when glyphosate was applied to the apical ramets (Figure 2)
Biomass and root mass ratio (RMR) of both whole clones and basal ramets experienced a significant reduction when glyphosate was applied to the basal or apical ramets (Figures 2 and 4)

Summary

Introduction

Coastal sand dunes are fragile ecosystems that usually contain both endemic and endangered species, and are a key objective for biodiversity conservation [1]. Biological invasions represent one of largest threats to natural ecosystems, including coastal sand dunes [2]. Invasive species may cause indirect effects on native plant species by modifying biotic and abiotic conditions of native communities and ecosystems [6]. Invasive species can damage ecosystem services and cause huge economic cost to society worldwide [7]. The management of invasive alien species is a high priority for countries around the world [8]. Expenditures associated with invasive alien species management entail a high economic cost, mostly allocated to post-invasion management actions [9]

Methods

Results

Discussion

Conclusion