TY - JOUR
T1 - A new preparation method for testate amoebae in minerogenic sediments
AU - Zheng, Xianglin
AU - Harper, Jason B
AU - Hope, Geoffrey
AU - Mooney, S
PY - 2019
Y1 - 2019
N2 - Testate amoebae are one of a few moisture-sensitive proxies available to study Holocene palaeohydrology.
Although the majority of research has been conducted on ombrotrophic peatlands in the Northern Hemisphere,
the application of testate amoebae in minerogenic sediments, such as minerotrophic peatlands and saltmarshes,
holds considerable promise but is often impeded by the low concentration of testate amoebae and by timeconsuming
counting. Here a new preparation protocol to concentrate testate amoebae is proposed; it removes
more minerogenic particles and organic matter, but results in negligible damage to testate amoebae. Sodium
pyrophosphate (Na4P2O7) is introduced to remove fine particles through deflocculation that, in contrast to the
commonly used chemical digestion/deprotonation via an alkaline treatment, is more physically benign to
testate amoebae. Furthermore, acetone is introduced as an organic co-solvent to increase the solubility of
organic matter in the alkaline treatment. We test the new protocol against standard, water-based methods and
find that the addition of sodium pyrophosphate yields the highest concentration and increases the total number
of testate amoebae recovered. Statistical analyses (multivariate ANOVA and ordination) suggest that the new
method retains the assemblage integrity. We conclude by recommending a protocol combining sodium
pyrophosphate, acetone and a mild alkaline treatment, as this combination yields the best slide clarity, reduced
counting time and results in negligible damage to testate amoebae.
AB - Testate amoebae are one of a few moisture-sensitive proxies available to study Holocene palaeohydrology.
Although the majority of research has been conducted on ombrotrophic peatlands in the Northern Hemisphere,
the application of testate amoebae in minerogenic sediments, such as minerotrophic peatlands and saltmarshes,
holds considerable promise but is often impeded by the low concentration of testate amoebae and by timeconsuming
counting. Here a new preparation protocol to concentrate testate amoebae is proposed; it removes
more minerogenic particles and organic matter, but results in negligible damage to testate amoebae. Sodium
pyrophosphate (Na4P2O7) is introduced to remove fine particles through deflocculation that, in contrast to the
commonly used chemical digestion/deprotonation via an alkaline treatment, is more physically benign to
testate amoebae. Furthermore, acetone is introduced as an organic co-solvent to increase the solubility of
organic matter in the alkaline treatment. We test the new protocol against standard, water-based methods and
find that the addition of sodium pyrophosphate yields the highest concentration and increases the total number
of testate amoebae recovered. Statistical analyses (multivariate ANOVA and ordination) suggest that the new
method retains the assemblage integrity. We conclude by recommending a protocol combining sodium
pyrophosphate, acetone and a mild alkaline treatment, as this combination yields the best slide clarity, reduced
counting time and results in negligible damage to testate amoebae.
U2 - 10.19189/MaP.2018.OMB.380
DO - 10.19189/MaP.2018.OMB.380
M3 - Article
SN - 1819-754X
VL - 24
SP - 1
EP - 12
JO - Mires and Peat
JF - Mires and Peat
ER -