Can soil testate amoebae be used for estimating the time since death? A field experiment in a deciduous forest

Szelecz, Ildikò; Fournier, Bertrand; Seppey, Christophe V. W.; Amendt, Jens; Mitchell, Edward A. D.

doi:10.1016/j.forsciint.2013.12.030

Cited by 38 publications

(22 citation statements)

References 51 publications

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“…In support for this view, in dry plots ventral aperture emerged as a significant trait at T6. Furthermore, community structure shifted towards the dominance of silica and agglutinate test composition, a common trait in mineral soils (Seppey et al, 2016;Szelecz et al, 2014;Tsyganov et al, 2012). On the contrary, in wet plots, where a compressed test does not represent a specific advantage, the proportion of species with a compressed test declined.…”

Section: Water Table Changes and Functional Traitsmentioning

confidence: 99%

Taxonomic and functional traits responses of Sphagnum peatland testate amoebae to experimentally manipulated water table

Koenig

Mulot

Mitchell

2018

Ecological Indicators

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Biomonitoring tools are useful to assess the impact of environmental changes on the functioning of ecosystems. Existing tools mostly require species identification, thus allowing to estimating changes in biodiversity, and possibly inferring ecosystem functioning, using functional diversity and traits based approaches. Testate amoebae are good indicators of surface moisture conditions in Sphagnum peatlands and are routinely used in palaeoecology. Their shells (tests), on which identification is based, can also be used to define functional traits and thus to infer changes in ecosystem functioning. We investigated the response of testate amoeba communities to manipulated water table depth (wet: −4 cm, intermediate: −15 cm, and dry: −25 cm) over time (seven time points, 19 months) using mesocosms by comparing two approaches: community structure and functional traits responses, using a combination of morphological (biovolume, length, aperture size and position) and physiological (mixotrophy/heterotrophy, shell material) traits. This is the first study investigating the effect of water table depth on testate amoeba assemblages over time using a mesocosm approach. Taxonomical and functional approaches showed similar response patterns, confirming that water level acted as a strong environmental filter. After one year Hyalosphenia papilio decreased in the dry treatment, and the community structure shifted towards a dominance of dry indicators (Nebela tincta complex, Corythion dubium, Euglypha compressa) and the selected functional traits (smaller, heterotrophic, compressed species, with a ventral aperture) corresponded to drought adaptations. In line with recent observational and transfer function studies exploring the use of testate amoebae functional traits, our experimental results illustrate how well-selected traits could be used to monitor the impact of present and past climatic changes on Sphagnum peatlands.

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Section: Water Table Changes and Functional Traitsmentioning

confidence: 99%

Taxonomic and functional traits responses of Sphagnum peatland testate amoebae to experimentally manipulated water table

Koenig

Mulot

Mitchell

2018

Ecological Indicators

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“…Molecular phylogenetic studies based on ribosomal RNA and protein gene sequences show that these organisms belong to the three supergroups Amoebozoa (Nikolaev et al, in peatlands (Beaulne et al, 2018), as a tool for monitoring restoration success Valentine et al, 2013), and as indicators in ecotoxicology (Amacker et al, 2018;Meyer et al, 2012). They have also been applied as trace evidence in forensic science (Swindles and Ruffell, 2009), and for defining post-mortem intervals (Seppey et al, 2016;Szelecz et al, 2014). As these organisms produce decay-resistant tests, they are commonly applied in palaeoenvironmental research Lamentowicz et al, 2009;Seddon et al, 2014;Wilmshurst et al, 2003), and have been successfully used to reconstruct past moisture conditions across a broad range of climatic zones (McGlone and Wilmshurst, 1999;Royles et al, 2016;Swindles et al, 2015;Swindles et al, 2016;Wilmshurst et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

McKeown

Wilmshurst

Duckert

et al. 2019

European Journal of Protistology

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Methodological advances are essential for robust ecological research. Quantitative reconstructions of environmental conditions using testate amoebae rely on sound taxonomy. While the taxonomy of large species is relatively well resolved, this is not the case for most small taxa (typically <45 m long). In New Zealand, peatlands contain a diversity of both cosmopolitan and characteristic large southern endemic taxa, but also have a high abundance of small taxa. The latter are often lumped into morphotypes reducing their value as ecological indicators. In this study, we demonstrate how (a) lumping small taxa versus splitting them into unique types, and (b) including or excluding them from community analysis influenced their ecological inference. We assessed testate amoeba composition in six peat bogs from New Zealand, three that were moderately-to-highly impacted, and three that were non-impacted. Environmental variables were measured at each sampling site and the surface testate amoeba community patterns and community-environment relationships compared. We found a clear division between impacted and non-impacted sites. Several distinct small taxa were more strongly related to water-table depth and conductivity, while the larger taxa were more correlated to pH. These results show that improved taxonomic resolution of small taxa can provide more informed environmental assessment.

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“…Schalenamöben oder Testaceen (Abbildung 5) sind eine Gruppe von einzelligen, mikroskopisch kleinen (10–300 μm) Protisten, die weltweit in verschiedenen Lebensräumen wie Moosen, Böden, Mooren, Seen, Flüssen und sogar Flussmündungen vorkommen. In Böden und Blattstreu erreichen sie eine Dichte von über 100 Individuen pro Gramm Trockenmasse . Sie vermehren sich mit einer Generationszeit von wenigen Tagen bis über einer Woche.…”

Section: Bodenorganismenunclassified

“…Durch Zellanfärbung sind lebende, enzystierte und tote Schalenamöben klar unter dem Mikroskop erkennbar, und ihr Mengenverhältnis lässt Rückschlüsse auf eventuelle Störungen ihres Lebensraums zu. Bei einer Untersuchung terrestrischer Schalenamöbengemeinschaften unter Schweinekadavern über einen Zeitraum von 10 Monaten, wurde deutlich, dass sich sowohl Dichte als auch Artenvielfalt (im Vergleich zu Kontrollgruppen) signifikant verändern . Bereits nach 22 Tagen blieb keine lebende Schalenamöbe unter den Kadavern zurück.…”

Section: Bodenorganismenunclassified

Interdisziplinarität in der Forensik

Amendt

Zissler²,

Lutz

et al. 2020

Biologie in unserer Zeit

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Zusammenfassung Die Ermittlung der Todeszeit ist eine wichtige Aufgabe der forensischen Wissenschaften. Nach 1–2 Tagen wird sie jedoch durch Autolyse und Fäulnis drastisch erschwert. Eine Kombination aus etablierten und neuen Methoden unterschiedlicher Disziplinen soll hier Abhilfe schaffen. Die morphologische Veränderungen eines Leichnams sind von dessen Liegezeit abhängig und können in einem Punktesystem klassifiziert werden: Die Altersbestimmung und Artenzusammensetzung von sich am Leichnam entwickelnden nekrophagen Insekten erlauben taggenaue Eingrenzungen des Besiedlungszeitpunktes, der Abbau von Proteinen der Skelettmuskulatur folgt einem charakteristischen, zeitabhängigen Degradationsmuster, Bodenorganismen unterhalb eines verwesenden Leichnams können durch Leichenflüssigkeiten negativ beeinträchtigt werden oder durch den damit verbundenen Eintrag von Nährstoffen wie Proteinen, Lipiden und Kohlenhydraten profitieren. Die kombinierte, interdisziplinäre Bewertung all dieser Parameter bietet vollkommen neue Möglichkeiten bei der Bestimmung von Todeszeiten, die Tage, Wochen oder Monate zurückliegen.

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Can soil testate amoebae be used for estimating the time since death? A field experiment in a deciduous forest

Cited by 38 publications

References 51 publications

Taxonomic and functional traits responses of Sphagnum peatland testate amoebae to experimentally manipulated water table

Taxonomic and functional traits responses of Sphagnum peatland testate amoebae to experimentally manipulated water table

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

Interdisziplinarität in der Forensik

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Can soil testate amoebae be used for estimating the time since death? A field experiment in a deciduous forest

Cited by 38 publications

References 51 publications

Taxonomic and functional traits responses of Sphagnum peatland testate amoebae to experimentally manipulated water table

Taxonomic and functional traits responses of Sphagnum peatland testate amoebae to experimentally manipulated water table

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands

Interdisziplinarität in der Forensik

Contact Info

Product

Resources

About

Assessing the ecological value of small testate amoebae (<45 μm) in New Zealand peatlands