Salinity Tolerance Thresholds and Acclimation Potential in the Invasive Macrophyte Crassula helmsii
- 1UMR 6553 ECOBIO (CNRS—Université de Rennes) France
Abstract
The salt gradient is a major driver of the composition of aquatic plant communities. The ionic composition of salt and exposure regime can influence the response of macrophytes, either positively or negatively. In European freshwaters, the New Zealand pigmyweed (Crassula helmsii) is a highly invasive macrophyte that should exhibit a small tolerance to salt, raising interest in salt-based control strategies. Two ex-situ experiments were conducted to evaluate the effects of salinity on C. helmsii. The first experiment assessed survival and morphological responses to four salinity levels (0, 15, 30 and 60 g/L) using either road or sea salts. The second experiment compared gradual versus direct exposure to elevated salinity (20 and 30 g/L). Salinity exposure reduced apical growth and biomass. No significant differences were detected between the effects of road salt and sea salt. Median effective concentration (EC50) was approximately 33 g/L. Moderate salinity stimulated branching and root production, whereas higher salinity (> 15 g/L) inhibited growth and increased mortality. Gradual exposure did not improve survival significantly compared with direct exposure. C. helmsii continued to grow at salinity levels up to 15 g/L, exceeding previously reported tolerance thresholds for the tested species. These findings indicate substantial tolerance to short-term stress and delayed mortality under progressive salinisation may suggest potential acclimation ability. Eradication of C. helmsii would require prolonged exposure to salinity levels approaching seawater concentration that should negatively affect other freshwater organisms and ecosystem functioning. Species salinity tolerance and potential acclimation suggest an increased invasion risk of C. helmsii for temporarily salinised freshwater ecosystems.
Related
- Biostimulant-Mediated Enhancement of Quinoa Tolerance to NaCl-Induced Salinity Stress Through Foliar Application of Ascorbic Acid, Saponins and Quinoa Seed Extract
- Halophyte-associated salt-tolerant rhizobacteria: ecological adaptation, mechanistic pathways, and translational relevance for wheat salinity tolerance
- Integrating physiological and proteomics signatures for understanding drought, salinity and alkalinity stress tolerance mechanisms in lentil
- Deciphering the dynamic genetic architecture of adult-plant salinity tolerance in bread wheat using multi-model GWAS and genomic prediction.
- Seedling stage phenotyping of rice genotypes from Eastern and Southern Africa for salinity stress tolerance
BibTeX
@article{gaudichet2026salinity,
title = {{Salinity Tolerance Thresholds and Acclimation Potential in the Invasive Macrophyte Crassula helmsii}},
author = {Corentin Gaudichet and Michèle Tarayre and Gabrielle Thiébaut},
journal = {Ecology and Evolution},
year = {2026},
month = oct,
doi = {10.1002/ece3.74496},
url = {https://hal.science/hal-05835740v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Salinity Tolerance Thresholds and Acclimation Potential in the Invasive Macrophyte Crassula helmsii
AU - Corentin Gaudichet
AU - Michèle Tarayre
AU - Gabrielle Thiébaut
PY - 2026
DA - 2026/10/01
JO - Ecology and Evolution
DO - 10.1002/ece3.74496
UR - https://hal.science/hal-05835740v1
AB - The salt gradient is a major driver of the composition of aquatic plant communities. The ionic composition of salt and exposure regime can influence the response of macrophytes, either positively or negatively. In European freshwaters, the New Zealand pigmyweed (Crassula helmsii) is a highly invasive macrophyte that should exhibit a small tolerance to salt, raising interest in salt-based control strategies. Two ex-situ experiments were conducted to evaluate the effects of salinity on C. helmsii. The first experiment assessed survival and morphological responses to four salinity levels (0, 15, 30 and 60 g/L) using either road or sea salts. The second experiment compared gradual versus direct exposure to elevated salinity (20 and 30 g/L). Salinity exposure reduced apical growth and biomass. No significant differences were detected between the effects of road salt and sea salt. Median effective concentration (EC50) was approximately 33 g/L. Moderate salinity stimulated branching and root production, whereas higher salinity (> 15 g/L) inhibited growth and increased mortality. Gradual exposure did not improve survival significantly compared with direct exposure. C. helmsii continued to grow at salinity levels up to 15 g/L, exceeding previously reported tolerance thresholds for the tested species. These findings indicate substantial tolerance to short-term stress and delayed mortality under progressive salinisation may suggest potential acclimation ability. Eradication of C. helmsii would require prolonged exposure to salinity levels approaching seawater concentration that should negatively affect other freshwater organisms and ecosystem functioning. Species salinity tolerance and potential acclimation suggest an increased invasion risk of C. helmsii for temporarily salinised freshwater ecosystems.
SN - 2045-7758
ER -