World Soil Day (WSD), held annually every December 5th, is a global initiative set up by the United Nations to raise awareness of the importance of healthy soils and to advocate for the sustainable management of soil resources. This year’s focus was on salt-affected soil and the impact of sustainable soil practices to prevent salinization.
Our expert ecologist Dr. Rosie Everett recently chaired a roundtable at the United Nation’s 2021 Climate Change Conference, with the focus of the discussion on the main ecological issues concerning climate change today. In relation to forensic ecology this considers how climate change could affect the analysis that ecologists do to provide support for major crime investigations, with one of the main points from Dr. Everett’s seminar being the impact of changes in soils associated with flooding.
Here we lift the lid on soil science as an ecological discipline and shine a spotlight on the ways in which soil science can aid major crime investigations.
What is soil science?
- Soils form across the UK within different environments (e.g. woodlands, parklands, gardens) and across different locations (e.g. local and regional areas) to form distinct characteristics
- Soil characteristics can be identified to provide a signature for regional patterns and to allow differentiation between environments
- These characteristics are based upon the composition of the soil which comprises of analysis of inorganic elements (such as particle size distributions and characterisation) and the organic component, such as living organisms within soils (e.g. diatoms).
How is soil science used in forensic investigations?
- Analysis of soil can be used to establish the profile that is specific to that environment – known as a control sample
- Soils seized from exhibits such as clothing, shoes and upholstery from vehicles can be examined to build a profile and establish characteristic features
- The control samples can then be compared with exhibits for a geographical match.
Moreover, soil evidence can be used to link pertinent places with deposition sites, contact sites and other scenes of interest to associate potential suspects with victims. It can also assist in the search and location of bodies while also providing intelligence, insight and discriminating evidence of contact.
Why is soil conservation important for forensic investigations?
While we don’t deal directly with issues surrounding soil conservation, the broader picture is that we have a good handle on the state of UK soils, and we understand their distribution.
This is the level of conservation that we’re aiming for. However, climate change and soil erosion can have a detrimental impact on the state of UK soils and therefore the way that we undertake soil analysis and investigation.
How does soil analysis contribute to major crime investigations?
Within major crime we use soil analysis to understand the environment. This is achieved by identifying the main characteristics of different soils in terms of their composition. We consider how this relates to the local and regional soil’s distribution.
We then use this for comparison with potential exhibits. In the context of major crime, the key examples include car examinations, digging implements for concealment of victims, and footwear.
In the past we have also conducted soil analysis within heritage crime, particularly with the comparison of soils from a scene with illegally metal-detected artefacts.
How varied are the different types of soils and are they easily distinguishable from one another?
In depends on the local geology and it also depends on the environment. What we are looking for are potential changes in the environment, for example if we are dealing with a scene within a woodland –how does this differ from the scene in an urban area, a grassland or a parkland.
Different types of soils can also be built into regional maps. We would then look at how a certain soil fits with the regional pattern of soil distribution. The British Geological Survey soil map distributes soils across the UK, and we often refer to that for comparison work.
Are soils particularly vulnerable or susceptible to climate change?
A huge issue at the moment is the impact of farming and subsistence and how it can cause damage to the environment. This is, in turn, impacted upon by climate change, so the warmer and wetter it gets the more of an impact that heavy rainfall surface runoff has. This causes huge problems with soil erosion.
What’s the significance of peatland soils in relation to climate change?
Peat soils are very important because they contain carbon. They are key for carbon capture and in the broader picture what we are trying to protect is the ecosystem that lives within soils.
Human interference such as intense agriculture can destroy some of these ecosystems which are really important to conserve.
Lastly, for the particularly inquisitive minds out there, here is an image of soils under a microscope:
Alecto Forensics is a UK leading forensic ecology service provider, delivering specialist forensic services and expertise to police forces across the UK.
We have over twenty years of forensic ecology experience within major crime investigation and pride ourselves on being an independent, quality-driven forensic service provider. We have a host of accredited experts and our expertise is available 24 hours 7 days a week.
We offer a full provision of service, from initial advice and support to scene deployment, laboratory analysis and final reporting.