Similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification
Fen–bog succession is accompanied by strong increases of carbon accumulation rates. We tested the prevailing hypothesis that living Sphagna have extraordinarily high cation exchange capacity (CEC) and therefore acidify their environment by exchanging tissue-bound protons for basic cations in soil wa...
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ftdatacite:10.6084/m9.figshare.c.3303465 2023-05-15T18:28:40+02:00 Similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification N. A. Soudzilovskaia J. H. C. Cornelissen H. J. During R. S. P. Van Logtestijn S. I. Lang R. Aerts 2016 https://dx.doi.org/10.6084/m9.figshare.c.3303465 https://figshare.com/collections/Similar_cation_exchange_capacities_among_bryophyte_species_refute_a_presumed_mechanism_of_peatland_acidification/3303465 unknown Figshare https://dx.doi.org/10.1890/09-2095.1 CC-BY http://creativecommons.org/licenses/by/3.0/us CC-BY Environmental Science Ecology FOS Biological sciences Collection article 2016 ftdatacite https://doi.org/10.6084/m9.figshare.c.3303465 https://doi.org/10.1890/09-2095.1 2021-11-05T12:55:41Z Fen–bog succession is accompanied by strong increases of carbon accumulation rates. We tested the prevailing hypothesis that living Sphagna have extraordinarily high cation exchange capacity (CEC) and therefore acidify their environment by exchanging tissue-bound protons for basic cations in soil water. As Sphagnum invasion in a peatland usually coincides with succession from a brown moss-dominated alkaline fen to an acidic bog, the CEC of Sphagna is widely believed to play an important role in this acidification process. However, Sphagnum CEC has never been compared explicitly to that of a wide range of other bryophyte taxa. Whether high CEC directly leads to the ability to acidify the environment in situ also remains to be tested. We screened 20 predominant subarctic bryophyte species, including fen brown mosses and bog Sphagna for CEC, in situ soil water acidification capacity (AC), and peat acid neutralizing capacity (ANC). All these bryophyte species possessed substantial CEC, which was remarkably similar for brown mosses and Sphagna. This refutes the commonly accepted idea of living Sphagnum CEC being responsible for peatland acidification, as Sphagnum 's ecological predecessors, brown mosses, can do the same job. Sphagnum AC was several times higher than that of other bryophytes, suggesting that CE (cation exchange) sites of Sphagna in situ are not saturated with basic cations, probably due to the virtual absence of these cations in the bog water. Together, these results suggest that Sphagna can not realize their CEC in bogs, while fen mosses can do so in fens. The fen peat ANC was 65% higher than bog ANC, indicating that acidity released by brown mosses in the CE process was neutralized, maintaining an alkaline environment. We propose two successional pathways indicating boundaries for a fen–bog shift with respect to bryophyte CEC. In neither of them is Sphagnum CE an important factor. We conclude that living Sphagnum CEC does not play any considerable role in the fen–bog shift. Alternatively, we propose that exclusively indirect effects of Sphagnum expansion such as peat accumulation and subsequent blocking of upward alkaline soil water transport are keys to the fen–bog succession and therefore for bog-associated carbon accumulation. Article in Journal/Newspaper Subarctic DataCite Metadata Store (German National Library of Science and Technology) |
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Open Polar |
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DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
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unknown |
topic |
Environmental Science Ecology FOS Biological sciences |
spellingShingle |
Environmental Science Ecology FOS Biological sciences N. A. Soudzilovskaia J. H. C. Cornelissen H. J. During R. S. P. Van Logtestijn S. I. Lang R. Aerts Similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification |
topic_facet |
Environmental Science Ecology FOS Biological sciences |
description |
Fen–bog succession is accompanied by strong increases of carbon accumulation rates. We tested the prevailing hypothesis that living Sphagna have extraordinarily high cation exchange capacity (CEC) and therefore acidify their environment by exchanging tissue-bound protons for basic cations in soil water. As Sphagnum invasion in a peatland usually coincides with succession from a brown moss-dominated alkaline fen to an acidic bog, the CEC of Sphagna is widely believed to play an important role in this acidification process. However, Sphagnum CEC has never been compared explicitly to that of a wide range of other bryophyte taxa. Whether high CEC directly leads to the ability to acidify the environment in situ also remains to be tested. We screened 20 predominant subarctic bryophyte species, including fen brown mosses and bog Sphagna for CEC, in situ soil water acidification capacity (AC), and peat acid neutralizing capacity (ANC). All these bryophyte species possessed substantial CEC, which was remarkably similar for brown mosses and Sphagna. This refutes the commonly accepted idea of living Sphagnum CEC being responsible for peatland acidification, as Sphagnum 's ecological predecessors, brown mosses, can do the same job. Sphagnum AC was several times higher than that of other bryophytes, suggesting that CE (cation exchange) sites of Sphagna in situ are not saturated with basic cations, probably due to the virtual absence of these cations in the bog water. Together, these results suggest that Sphagna can not realize their CEC in bogs, while fen mosses can do so in fens. The fen peat ANC was 65% higher than bog ANC, indicating that acidity released by brown mosses in the CE process was neutralized, maintaining an alkaline environment. We propose two successional pathways indicating boundaries for a fen–bog shift with respect to bryophyte CEC. In neither of them is Sphagnum CE an important factor. We conclude that living Sphagnum CEC does not play any considerable role in the fen–bog shift. Alternatively, we propose that exclusively indirect effects of Sphagnum expansion such as peat accumulation and subsequent blocking of upward alkaline soil water transport are keys to the fen–bog succession and therefore for bog-associated carbon accumulation. |
format |
Article in Journal/Newspaper |
author |
N. A. Soudzilovskaia J. H. C. Cornelissen H. J. During R. S. P. Van Logtestijn S. I. Lang R. Aerts |
author_facet |
N. A. Soudzilovskaia J. H. C. Cornelissen H. J. During R. S. P. Van Logtestijn S. I. Lang R. Aerts |
author_sort |
N. A. Soudzilovskaia |
title |
Similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification |
title_short |
Similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification |
title_full |
Similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification |
title_fullStr |
Similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification |
title_full_unstemmed |
Similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification |
title_sort |
similar cation exchange capacities among bryophyte species refute a presumed mechanism of peatland acidification |
publisher |
Figshare |
publishDate |
2016 |
url |
https://dx.doi.org/10.6084/m9.figshare.c.3303465 https://figshare.com/collections/Similar_cation_exchange_capacities_among_bryophyte_species_refute_a_presumed_mechanism_of_peatland_acidification/3303465 |
genre |
Subarctic |
genre_facet |
Subarctic |
op_relation |
https://dx.doi.org/10.1890/09-2095.1 |
op_rights |
CC-BY http://creativecommons.org/licenses/by/3.0/us |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.6084/m9.figshare.c.3303465 https://doi.org/10.1890/09-2095.1 |
_version_ |
1766211228372303872 |