Project

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The effect of cadavers on soil ecology: biotic and functional responses (CADAVER)

English title The effect of cadavers on soil ecology: biotic and functional responses (CADAVER)
Applicant Mitchell Edward
Number 141188
Funding scheme Project funding (Div. I-III)
Research institution Laboratoire de biologie du sol Institut de biologie Université de Neuchâtel
Institution of higher education University of Neuchatel - NE
Main discipline Ecology
Start/End 01.08.2012 - 31.12.2015
Approved amount 315'000.00
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All Disciplines (4)

Discipline
Ecology
Environmental Research
Legal sciences
Zoology

Keywords (10)

soil ecology; ecological succession; forensic science; community ecology; soil microorganisms; cadaver decomposition; bioindication; soil invertebrates; soil protozoa; microbial ecology

Lay Summary (English)

Lead
Lay summary

Cadaver decomposition has a clear impact on the soil ecosystem due to large, localised inputs of nutrients, especially carbon, nitrogen and phosphorous, as well as microclimatic effects (e.g. soil humidity and temperature). Cadaveric materials are rapidly introduced into the soil environment and assimilated by soil communities to form a “cadaver decomposition island (CDI)”. This “pulse of resources” affects the soil biota and functions drastically and therefore constitutes a natural disturbance; yet these effects are not well understood. This natural perturbation contributes to soil biological and functional diversity through the contrasted responses of different taxa and associated processes and the spatial and temporal heterogeneities caused by the presence of cadavers. Once the decomposition process is completed the soil ecosystem is thought to gradually return to a “normal” condition. These patterns and processes are relevant to general soil biology and to applications in forensic science, yet there is little data on cadaver decomposition effects on the soil biota and functions and the patterns and pace of secondary succession leading back to the initial condition.

A key aspect of forensic research is to develop tools to determine if a cadaver has decomposed in a certain place and how long ago the death occurred (the post-mortem interval – PMI). Forensic pathology uses several tools (e.g. body temperature, rigor mortis, insect infestation) but is usually not precise beyond 3-4 weeks. Hypothesised dynamic changes in the soil biota over a longer period (months to years) both in the disturbance and the recovery phases should allow the developing new tools in forensic taphonomy for estimating the time since death and the location of graves (e.g. if corpses were removed).

In this project we study the effects of cadavers on the soil biota in both fundamental (disturbance and nutrient pulses impact on soil biota) and applied (potential of soil biota and functions as indicators for forensic applications) perspectives. We conduct a fully factorial experiment to assess how a pig (standard model in forensic science) cadaver influences the soil biota and functioning and how the soil environment recovers from this perturbation. In addition to the cadavers and control treatments, fake pigs (i.e. filled cloth bags of equivalent size, but without cadaveric fluids) and pigs decomposing 2m above the soil (to test the influence of cadaveric fluids without the weight of the corpse) will be used to separate microclimatic and chemical effects, the latter being hypothesised as having a stronger influence. Soil samples from real forensic cases (if available) and nearby control soil will also be studied to test the broader applicability of the newly developed indicators and expand the range of natural conditions studied. As insects are supposed to be a major driving force regarding the speed and amount of decomposition (and much better understood than the soil biota), classical forensic entomology analyses will also be performed for comparison with the changes in the soil biota.

This research addresses fundamental soil ecology (disturbance, resilience and succession – linkages among taxa, abiotic variables and functions) and applied forensic science (bioindication, PMI estimation) that have never been addressed in the same study. The project is divided into 5 tasks. 1) Insect succession on cadavers in relation to microclimate. 2) Soil physico-chemical characteristics. 3) Molecular diversity and community structure of soil Bacteria, micro-Eukaryotes and mesofauna. 4) Morphological characterisation of soil taxa (testate amoebae and selected groups of mesofauna). 5) Community and ecosystem ecology modelling and definition of abiotic and biotic (bio)indicators of post-mortem interval.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Comparative analysis of bones, mites, soil chemistry, nematodes and soil micro-eukaryotes from a suspected homicide to estimate the post-mortem interval
Szelecz Ildikó, Lösch Sandra, Seppey Christophe V. W., Lara Enrique, Singer David, Sorge Franziska, Tschui Joelle, Perotti M. Alejandra, Mitchell Edward A. D. (2018), Comparative analysis of bones, mites, soil chemistry, nematodes and soil micro-eukaryotes from a suspected homicide to estimate the post-mortem interval, in Scientific Reports, 8(1), 25-25.
Soil chemistry changes beneath decomposing cadavers over a one-year period
Szelecz Ildikó, Koenig Isabelle, Seppey Christophe V.W., Le Bayon Renée-Claire, Mitchell Edward A.D. (2018), Soil chemistry changes beneath decomposing cadavers over a one-year period, in Forensic Science International, 286, 155-165.
Soil protists: a fertile frontier in soil biology research
Geisen Stefan, Mitchell Edward A D, Adl Sina, Bonkowski Michael, Dunthorn Micah, Ekelund Flemming, Fernández Leonardo D, Jousset Alexandre, Krashevska Valentyna, Singer David, Spiegel Frederick W, Walochnik Julia, Lara Enrique (2018), Soil protists: a fertile frontier in soil biology research, in FEMS Microbiology Reviews, 42(3), 293-323.
The importance of Saprinus semistriatus (Coleoptera: Histeridae) for estimating the minimum post-mortem interval
Szelecz I., Feddern N., Seppey C.V.W., Amendt J., Mitchell E.A.D. (2018), The importance of Saprinus semistriatus (Coleoptera: Histeridae) for estimating the minimum post-mortem interval, in Legal Medicine, 30, 21-27.
Soil protistology rebooted: 30 fundamental questions to start with
Geisen Stefan, Mitchell Edward A.D., Wilkinson David M., Adl Sina, Bonkowski Michael, Brown Matthew W., Fiore-Donno Anna Maria, Heger Thierry J., Jassey Vincent E.J., Krashevska Valentyna, Lahr Daniel J.G., Marcisz Katarzyna, Mulot Matthieu, Payne Richard, Singer David, Anderson O. Roger, Charman Dan J., Ekelund Flemming, Griffiths Bryan S., Rønn Regin, Smirnov Alexey, Bass David, Belbahri Lassaâd, Berney Cédric, et al. (2017), Soil protistology rebooted: 30 fundamental questions to start with, in Soil Biology and Biochemistry, 111, 94-103.
Effects of decomposing cadavers on soil nematode communities over a one-year period
Szelecz Ildikó, Sorge Franziska, Seppey Christophe V.W., Mulot Matthieu, Steel Hanne, Neilson Roy, Griffiths Bryan S., Amendt Jens, Mitchell Edward A.D. (2016), Effects of decomposing cadavers on soil nematode communities over a one-year period, in Soil Biology and Biochemistry, 103, 405-416.
Response of forest soil euglyphid testate amoebae (Rhizaria: Cercozoa) to pig cadavers assessed by high-throughput sequencing
Seppey Christophe V. W., Fournier Bertrand, Szelecz Ildikò, Singer David, Mitchell Edward A. D., Lara Enrique (2016), Response of forest soil euglyphid testate amoebae (Rhizaria: Cercozoa) to pig cadavers assessed by high-throughput sequencing, in International Journal of Legal Medicine, 130(2), 551-562.
Response of forest soil euglyphid testate amoebae (Rhizaria: Cercozoa) to pig cadavers assessed by high-throughput sequencing
Seppey Christophe V W, Fournier Bertrand, Szelecz Ildikò, Singer David, Mitchell Edward A D, Lara Enrique (2015), Response of forest soil euglyphid testate amoebae (Rhizaria: Cercozoa) to pig cadavers assessed by high-throughput sequencing, in International Journal of Legal Medicine, published online(published ), published -published.
Can soil testate amoebae be used for estimating the time since death? A field experiment in a deciduous forest
Szelecz Idikò Fournier Bertrand Seppey Christophe Amendt J Mitchell Edward (2014), Can soil testate amoebae be used for estimating the time since death? A field experiment in a deciduous forest, in Forensic Science International, 236, 90-96.
Invertebrates: Above ground, below ground and in court?
Szelecz Ildikò, Sorge Franziska, Feddern Nina, Seppey Christophe V.W, Mulot Matthieu, Amendt Jens, Mitchell Edward A. D. (2014), Invertebrates: Above ground, below ground and in court?, in Antenna, Bulletin of the Royal Entomology Society, United Kingdom, Special issue, 115-116.

Collaboration

Group / person Country
Types of collaboration
Institute of Forensic Medicine, Frankfurt am Main Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
University of Reading, School of Biological Sciences Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Bangor University, School of Biological Sciences Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Research Unit Nematology, Universiteit Gent Belgium (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
University of Neuchâtel, Laboratory Soil & Vegetation Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Exchange of personnel
The James Hutton Institute, Invergowrie, Dundee Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
VII European Congress of Protistology & International Society of Protistologists - ECOP - ISOP Joint Meeting, 5-10 September 2015, Seville, Spain Poster Reczuga MK, Seppey C, Szelecz I, Fournier B, Singer D, Lara E, Mulot M, Mitchell EAD. 2015. Response of soil micro-eukaryotes to cadaver decomposition as assessed by high throughput sequencing. 05.09.2015 Seville, Spain Szelecz Ildiko; Mitchell Edward; Seppey Christophe; Lara Enrique;
VII European Congress of Protistology & International Society of Protistologists - ECOP - ISOP Joint Meeting, 5-10 September 2015, Seville, Spain Poster Seppey CVW, Lara E, Singer D, Szelecz I, Fournier B, Samaritani E, Mitchell EAD. 2015. Metabarcoding of soil eukaryotes – multiple applications for biodiversity assessment to applied ecological research. 05.09.2015 Seville, Spain Lara Enrique; Seppey Christophe; Mitchell Edward; Szelecz Ildiko;
34th Meeting of the German Society of Protistology Individual talk Reczuga MK, Seppey C, Szelecz I, Fournier B, Singer D, Lara E, Mitchell EAD. 2015. Response of soil micro-eukaryotes to cadaver decomposition as assessed by high throughput sequencing. 03.06.2015 Magdeburg, Germany Mitchell Edward;
12th Meeting of the European Association for Forensic Entomology (EAFE), 06-09 May 2015, Huddersfield, UK. Individual talk Szelecz I, Feddern N, Fournier B, Seppey C, Amendt J, Mitchell EAD. 2015. Saprinus semistriatus- a lazy little fellow? 06.05.2015 Huddersfield, Great Britain and Northern Ireland Mitchell Edward; Seppey Christophe; Szelecz Ildiko;
First Global Soil Biodiversity Conference, Dijon, France, 2-5 December 2014. Poster Szelecz I, Sorge S, Mulot M, Fournier B, Seppey C, Amendt J, Mitchell EAD. 2014. Cadaver effects on soil biodiversity- results from two field experiments. 02.12.2014 Dijon, France Szelecz Ildiko; Seppey Christophe; Mitchell Edward;
First Global Soil Biodiversity Conference, Dijon, France, 2-5 December 2014. Poster Seppey C, Szelecz I, Fournier B, Tarnawski S-E, Mitchell EAD, Lara E. 2014. Metabarcoding of micro-eukaryotes – multiple applications from biodiversity assessment to applied ecological research. 02.12.2014 Dijon, France Seppey Christophe; Szelecz Ildiko; Mitchell Edward; Lara Enrique;
93. Jahrestagung Deutsche Gesellschaft für Rechtsmedizin (DGRM), Heringsdorf, Germany, 09-13 September 2014 Individual talk Feddern N, Szelecz I, Mulot M, Sorge F, Mitchell EAD, Amendt J. 2014. Insektenbesiedlung und Verwesung von hängenden und aufliegenden Schweinekadavern 13.09.2014 Heringsdorf, Germany Szelecz Ildiko; Mitchell Edward;
93. Jahrestagung Deutsche Gesellschaft für Rechtsmedizin (DGRM), Heringsdorf, Germany, 09 – 13 September 2014. Individual talk Sorge F, Szelecz I, Amendt J, Seppey C, Mulot M, Mitchell EAD. 2014. Soil beneath cadavers – Influence of decomposition on selected chemical markers and free-living terrestrial nematodes. 09.09.2014 Heringsdorf, Germany Mitchell Edward; Seppey Christophe; Szelecz Ildiko;
7th International Symposium on Testate Amoebae 8 to 12 September 2014 Poznań, Poland Individual talk Koenig I, Mulot M, Szelecz I, Fournier B, Lara E, Mitchell EAD. 2014. Response of testate amoeba functional diversity to environmental gradients, stress and perturbation. 08.09.2014 Poznan, Poland Szelecz Ildiko; Lara Enrique; Mitchell Edward;
10th European Congress of Entomology York, UK, 3-8 August 2014 Poster Feddern N, Szelecz I, Seppey C, Mulot M, Amendt J, Mitchell EAD. 2014. Comparison of the insect fauna of hanging and ground pig cadavers. 03.08.2014 York, Great Britain and Northern Ireland Mitchell Edward; Szelecz Ildiko; Seppey Christophe;
10th European Congress of Entomology York, UK, 3-8 August 2014. Individual talk Szelecz I, Sorge F, Feddern N, Seppey C, Mulot M, Amendt J, Mitchell EAD. Impact of cadavers on above- and below-ground invertebrates and soil function. 03.08.2014 York, Great Britain and Northern Ireland Szelecz Ildiko; Mitchell Edward; Seppey Christophe;
Eukaryotic –Omics: Exploring and testing with next-generation sequencing - 24 - 25 April 2014. Geneva, Switzerland. Talk given at a conference Seppey C, Fournier B, Szelecz I, Singer D, Mitchell EAD, Lara E. 2014. Euglyphids communities in Cadaver Decomposition Island by a metabarcoding approach 24.04.2014 Geneva, Switzerland Szelecz Ildiko; Lara Enrique; Mitchell Edward; Seppey Christophe;
3rd ENFSI APST WG 8 (Animal Plant and Soil Traces meeting of the European Network of Forensic Science Institutes), Rome, Italy, 02- 04 April 2014 . Talk given at a conference Szelecz I, Amendt J, Sorge F, Seppey C, Mulot M, Mitchell EAD. 2014. Soil beneath cadavers –Influence of decomposition on selected chemical markers and free-living terrestrial nematodes, 02.04.2014 Rome, Italy Seppey Christophe; Szelecz Ildiko; Mitchell Edward;
Invited seminar – Institute of Legal Medicine, Frankfurt am Main, Germany. 17.03 2014. Individual talk Szelecz I, Seppey C, Sorge F, Mulot M, Amendt J, Mitchell EAD. 2014. Decomposing cadavers on soil. 17.03.2014 Frankfurt am Main, Germany Mitchell Edward; Szelecz Ildiko; Seppey Christophe;
Invited seminar – Institute of Legal Medicine, Frankfurt am Main, Germany. 17.03 2014. Individual talk Seppey C, Fournier B, Szelecz I, Singer D, Mitchell EAD, Lara E. 2014. Euglyphids communities in Cadaver Decomposition Island by a metabarcoding approach. 17.03.2014 Frankfurt am Main, Germany Szelecz Ildiko; Seppey Christophe; Lara Enrique; Mitchell Edward;
32nd Meeting of the German Society for Protistology. Warth-Weiningen, Switzerland, 27 February – 2 March 2013 Individual talk Szelecz I, Klang C, Fournier B, Amendt J, Heurich M, Mitchell EAD. 2013. Testate amoebae in soil – their potential as an indicator of time since death 27.02.2013 Warth-Weiningen, Switzerland Mitchell Edward; Szelecz Ildiko;
32nd Meeting of the German Society for Protistology. Warth-Weiningen, Switzerland, 27 February – 2 March 2013. Individual talk Mitchell EAD, Szelecz I, Klang C, Seppey C, Fournier B, Mulot M, Amendt J, Heurich M, Lara E. 2013. Response of soil testate amoebae to the presence of a decomposing pig cadaver – a study using morphological and molecular approaches. 27.02.2013 Warth-Weiningen, Switzerland Mitchell Edward; Seppey Christophe; Szelecz Ildiko;
32nd Meeting of the German Society for Protistology. Warth-Weiningen, Switzerland, 27 February – 2 March 2013. Individual talk Seppey C, Fournier B, Mulot M, Mitchell EAD, Szelecz I, Lara E. 2013. Changes in soil Euglyphida communities under pigs cadavers assessed by high throughput sequencing : a new indicator of the post mortem interval (PMI)? 27.02.2013 Warth-Weiningen, Switzerland Lara Enrique; Seppey Christophe; Szelecz Ildiko; Mitchell Edward;
The 6th International Symposium on Testate Amoebae (ISTA6) Xiamen, China - 15-18 October 2012 Talk given at a conference KEYNOTE TALK - Progress and perspectives in testate amoeba ecology 15.10.2012 Xiamen, China Mitchell Edward;


Self-organised

Title Date Place
Forensic Ecology 18.02.2015 University of Neuchâtel, Switzerland

Communication with the public

Communication Title Media Place Year

Associated projects

Number Title Start Funding scheme
116825 Role of organic matter and soil biota on first steps of soil structuring. The case of alluvial soils from alpine to plain levels 01.10.2007 Project funding (Div. I-III)
150817 High-throughput sequencing for research on evolution and ecology of microeukaryotes 01.12.2013 R'EQUIP
109709 Addressing challenges in the ecology, biogeography, and taxonomy of testate amoebae for their use as paleoclimatic indicators 01.08.2006 Project funding (Div. I-III)
129981 Effects of climate change on plant-microbe interactions for nutrient acquisition in bogs: implications for carbon and nutrient dynamics (CLIMABOG) 01.04.2010 Project funding (Div. I-III)
163431 The effect of cadavers, blood, urine and faeces on soil ecology (CADAVER-2) 01.01.2016 Project funding (Div. I-III)

Abstract

Cadaver decomposition has a clear impact on the soil ecosystem due to large, localised inputs of nutrients, especially C, N & P, as well as microclimatic effects. Cadaveric materials are rapidly introduced into the soil environment and assimilated by soil communities to form a “cadaver decomposition island (CDI)”. This “pulse of resources” affects the soil biota and functions drastically; yet these effects are not well understood. This natural perturbation contributes to biological and functional diversity through the contrasted responses of different taxa and associated processes and the spatial and temporal heterogeneities caused by the presence of cadavers. Once the decomposition process is completed the soil ecosystem is thought to gradually return to a “normal” condition. These patterns and processes are relevant to general soil biology and application in forensic science, yet there is little data on cadaver decomposition effects on the soil biota and functions and the patterns and pace of secondary succession leading back to the initial condition. We plan to study the effects of cadavers on the soil biota in both fundamental (disturbance and nutrient pulses impact on soil biota) and applied (potential of soil biota and functions as indicators for forensic applications) perspectives.A key aspect of forensic research is to develop tools to determine if a cadaver has decomposed in a certain place and how long ago the death occurred (the post-mortem interval - PMI). Forensic pathology uses several tools (e.g. body temperature, rigor mortis, insect infestation) but is usually not precise beyond 3-4 weeks. Hypothesised dynamic changes in the soil biota over a longer period (months to years) both in the disturbance and the recovery phases should allow the developing new tools in forensic taphonomy for estimating the time since death and the location of graves (e.g. if corpses were removed).We plan to conduct a fully factorial experiment to assess how a pig (standard model in forensic science) cadaver influences the soil biota and functioning and how the soil environment recovers from this perturbation. In addition to the cadavers and control treatments, fake pigs (i.e. filled cloth bags of equivalent size, but without cadaveric fluids) and pigs decomposing 2m above the soil (to test the influence of cadaveric fluids without the weight of the corpse) will be used to separate microclimatic and chemical effects, the latter being hypothesised as having a stronger influence. Soil samples from real forensic cases (if available) and nearby control soil will also be studied to test the broader applicability of the newly developed indicators and expand the range of natural conditions studied. As insects are supposed to be a major driving force regarding the speed and amount of decomposition (and much better understood than the soil biota), classical forensic entomology analyses will also be performed for comparison with the changes in the soil biota. This research addresses fundamental soil ecology (disturbance, resilience and succession - linkages among taxa, abiotic variables and functions) and applied forensic science (bioindication, PMI estimation) that have never been addressed in the same study. The project is divided into 5 tasks. 1) Insect succession on cadavers in relation to microclimate. 2) Soil physico-chemical characteristics. 3) Molecular diversity and community structure of soil Bacteria, micro-Eukaryotes and mesofauna assessed by pyrosequencing. 4) Morphological characterisation of testate amoebae and mesofauna communities. 5) Community and ecosystem ecology modelling (species/species traits-environment-function correlations, path analysis to explore cause/effects relationships, and testing if the nutrient pulse leads to phylogenetic clumping in soil communities) and definition of abiotic and biotic (bio)indicators of post-mortem interval.
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