Managing the invasive plant Carpobrotus edulis: is mechanical control or specialized natural enemy more effective?

0546713 - BÚ 2022 RIV GB eng J - Journal Article
Núñez-González, N. - Rodríguez, Jonatan - González, L.
Managing the invasive plant Carpobrotus edulis: is mechanical control or specialized natural enemy more effective?
Journal of Environmental Management. Roč. 298, 15 Nov (2021), č. článku 113554. ISSN 0301-4797. E-ISSN 1095-8630
R&D Projects: GA ČR GA19-13142S
Institutional support: RVO:67985939
Keywords : biocontrol * invasion ecology * plant-herbivore interactions
OECD category: Ecology
Impact factor: 8.910, year: 2021
Method of publishing: Open access with time embargo
https://doi.org/10.1016/j.jenvman.2021.113554

Carpobrotus edulis is an invasive clonal plant with drastic effects on biodiversity and functioning of coastal ecosystems. In recent years, authorities and land managers have implemented diverse management strategies that usually focus on mechanical removal and chemical control. However, applying mechanical control to remove C. edulis may cause indirect adverse effects since it could increase the probability of spreading new propagules, which do not lose their physiological activity. Therefore, reducing the physiological activity of these plant fragments should be a priority to avoid their spread and re-rooting. Our goal was to assess the plant regeneration capacity after applying mechanical control (i) when placing the plant material on different types of ground surface (on sand, on stones and using rooted plants as control) and (ii) combined with the attack of specialized herbivores (the soft scale Pulvinariella mesembryanthemi). To achieve this, we evaluated how these two factors (ground surface and herbivory) affected the plant physiological activity, its survival and re-rooting, biometric measurements, shoot and root nutrient composition and biochemical parameters (total phenols and tannins). Regardless of the ground surface type, our results indicated that the specialist herbivore greatly affected the C. edulis parameters studied. The attack of P. mesembryanthemi stimulated the plant defence mechanisms, even in those individuals with less photosynthetic activity. Furthermore, P. mesembryanthemi severely reduced the biomass and volume of plant material. Decomposition of C. edulis was accelerated by the combination be-tween the inoculation of P. mesembryanthemi and placing the plants on the stones ground surface. Overall, preventing plant re-rooting by avoiding connection to the soil is an effective method of reducing its viability after the eighth-tenth month. After applying mechanical control, we recommend placing C. edulis fragments over an inert ground surface to avoid re-rooting, which would favour its death. We conclude that the combination of mechanical control and P. mesembryanthemi or even direct inoculation with this specialist herbivore could help authorities and land managers to improve management strategies for C. edulis.
Permanent Link: http://hdl.handle.net/11104/0324960