Abstract
Seasonal wetlands undergo recurrent inundation and contraction, creating strong hydrochemical variability and non–independent observations within pans. We tested whether this variability translated into diatom differentiation in five pans within each of two South African Ramsar wetland systems, Makuleke and Nylsvley, during cool–dry and hot–wet seasons. Two field replicates per pan–season yielded 40 diatom samples and 40 environmental records. Environmental replicates were averaged within pan–season; diatom relative abundances were calculated within each replicate and averaged with equal weight. Fifty–three taxa were detected. Makuleke had higher temperature, pH, total dissolved solids, conductivity and several major ions than Nylsvley, whereas temperature, total dissolved solids, conductivity, nitrate and sodium differed between seasons. Hierarchical permutation tests detected no community difference between systems or system by season interaction, and the seasonal pattern approached but did not reach the 0.05 threshold. Rarefied diversity and the six variable canonical correspondence model were also non–significant. Thus, hydrochemical separation did not yield supported assemblage separation at the sampled scale. These results caution against inferring ecological status from nested samples and identify repeated, substrate consistent monitoring as necessary for diatom–based assessment of seasonal wetlands.
Acknowledgements
Special thanks to Manelisi Mthombeni, Annah Malungani, Nelisiwe Ngomane, Thandiwe Mosia and Pippa Huchzermeyer for assisting with field sampling.
Funding
The study was funded by the National Research Foundation Thuthuka grant (UID: TTK240409213108; TTK230508103682). NM was funded by the University of Mpumalanga Vice Chancellor Scholarship. We further acknowledge the funding received from the Junior Research Fellowship of the University Capacity Development Programme, Department of Higher Education and Training.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Consent to participate
All authors agreed to participate in this manuscript and made meaningful contributions.
Consent to publish
All authors agreed to have this manuscript published and made meaningful contributions.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Reprints and permissions
About this article
Cite this article
Madonsela, N., Mangadze, T., Mpopetsi, P. et al. Linking environmental variability to diatom assemblages in seasonal wetlands.
Sci Rep (2026). https://doi.org/10.1038/s41598-026-74539-8
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-026-74539-8
Keywords
- Temporary wetlands
- Ramsar sites
- Benthic diatoms
- Repeated measures
- Rarefaction
- Hydrochemistry
Source: Ecology - nature.com
