Earthworm applications: harnessing ecosystem services
Submitting InstitutionUniversity of Central Lancashire
Unit of AssessmentGeography, Environmental Studies and Archaeology
Summary Impact TypeEnvironmental
Research Subject Area(s)
Environmental Sciences: Environmental Science and Management, Soil Sciences
Engineering: Environmental Engineering
Summary of the impact
The applied use of earthworms in soil restoration, bio-monitoring,
agro-ecosystems and organic waste management has had wide-reaching impact
on the commercial sector and the public. A variety of commercial groups
(such as the Forestry Commission and BAE Systems) have benefitted from
this research in both the UK and abroad. In addition to this, earthworm
research has also reached the public domain through outreach activities
and media coverage. For example, this UoA was involved in a National Open
Air Laboratories campaign. Our earthworm identification guide produced in
collaboration with the Natural History Museum in London has now been
widely distributed and used.
This represents aspects of the Earthworm Research Group (ERG), comprising
two full time staff (Butt and Lowe), alongside research students and
collaborations from external associates. General earthworm survey work has
been conducted across Britain and beyond, to address specific questions
relating to habitat suitability but also linking with historical human
activities, e.g. effects of agriculture and forestry on soils and
earthworms. Focus has been on rapid recent changes and on longer term
factors affecting soil properties and the influence of earthworms within
these anthropogenic systems. The Island of Rum, Inner Hebrides, managed by
Scottish Natural Heritage has been one focal location where the role of
earthworms in soil rehabilitation has been a key element in our research.
Restoration ecology is an established research area, developed in this
UoA since the mid-1990s with the specific focus of using earthworms in
soil bio-stimulation. Use has been made of a patented technique (the
Earthworm Inoculation Unit) to target earthworm-deficient soils such as
landfill, post-industrial and ex-agricultural sites. This research
utilises growth and reproduction data of soil-dwelling earthworms gathered
from controlled laboratory experimentation. Once produced and inoculated
into field soils, earthworms and their ecosystem service activities are
monitored over time. Soil development and pedogenesis through burrowing
and soil turnover are critical to biological soil restoration. The
combination of earthworm species used and their interactions is also vital
and soil-dependent. Water infiltration into soils is assisted through
macropore (vertical earthworm burrow) creation and has been investigated
using a novel technique for estimating burrow dimensions via
resin-casting. Earthworm populations have also been monitored to assess
their availability as food for legally protected vertebrates as a part of
mitigation measures at sites where soil disruption has occurred (e.g.
after development of Runway 2 at Manchester Airport).
The ability to maintain and produce (known exposure-rated) naïve earthworms is of
considerable value and has led to a further research strand using
earthworms to monitor bio-availability of soil contaminants. Ecotoxicology
is a growing environmental concern and earthworms can act as a solution
(bio-remediation) to some problems and as a monitoring tool to others. To
further enhance their use, a technique was developed to permanently tag
earthworms so that mark-release- recapture methods can be used to assess
accumulation of contaminants. Management of organic waste materials
through land spreading and the mode of incorporation into the soil by
earthworms and effects on the soils are also studied. This links directly
with ecotoxicological research to provide an overarching programme
investigating earthworms in waste and environmental management. Equally,
composting and vermi-composting have been investigated as methods for
reducing volumes of organic wastes and producing useful by-products.
A further development, building on culture techniques of soil-dwelling
species, has been a role within novel DNA analysis of earthworms to verify
species identification and to collect data to assist construction of a
"Barcode of Life Database" (BOLD).
Key researchers: Kevin Butt (Reader in Ecology) employed at UCLan
since 1994; Chris Lowe (Senior Lecturer in Waste and Environmental
Management): Research Fellow at UCLan (2005- 2009), permanent since 2009.
References to the research
Dupont, L., Lazrek, F., Porco, D., King, R.A., Rougerie, R.,
Symondson. W. O. C., Livet, A., Richard, B. Decaens, T., Butt, K.R.
and Mathieu, J. (2011) New insight into the genetic structure of the Allolobophora
chlorotica aggregate in Europe using microsatellite and
mitochondrial data. Pedobiologia 54, 217-224.
Butt, K. R. (2008) Earthworms in soil restoration: lessons learnt
from UK case studies of land reclamation. Restoration Ecology 16,
Butt, K. R., Lowe, C. N., Beasley, T., Hanson, I. and Keynes, R.
(2008) Darwin's earthworms revisited. European Journal of Soil Biology
Butt, K. R. andLowe, C.N. (2007) A viable technique for
tagging earthworms with visible implant elastomer. Applied Soil
Ecology 35, 454-457.
Lowe, C. N. and Butt, K. R. (2005) Culture techniques for
soil dwelling earthworms: A review. Pedobiologia 49, 401-413.
Butt, K. R., Nieminen, M. A., Sirén, T., Ketoja, E. and Nuutinen,
V. (2005) Population and behavioural level responses of arable soil
earthworms to boardmill sludge application. Biology and Fertility of
Soils 42, 163-167.
Details of the impact
The introduction of earthworms into degraded or newly restored land is
known to promote soil improvement. However, obtaining the most appropriate
species in the large numbers required can be costly and time consuming.
Development of the Earthworm Inoculation Unit (EIU) technique has proved
successful and has led to long-term monitoring of sites in the UK and
overseas, with on- going academic and commercial activity. Specific
post-industrial work took place at Calvert Landfill site, Buckinghamshire
in collaboration with the Forestry Commission (FC), including £24,000
funding (Short Rotation Forestry and earthworms: Impacts and responses).
Here interactions between earthworms and trees were investigated and work
established that earthworm communities could influence tree growth. This
has led to further collaboration (0.5 funding of a PhD) with the FC, where
work examined the effects of earthworms on short rotation forestry
production. In the late 1990s at the rehabilitated Hallside Steelworks
site, Scotland, earthworm inoculation was used to assist incorporation of
sewage sludge and colliery spoil to build new soil. This was linked with a
consortium of interested groups (including Scottish Natural Heritage) and
the results from here and elsewhere have convinced managers of a large
disused ordnance site in Scotland to investigate potential commercial
applications. The EIU technique has also been employed by MTT, Agrifood
Research in Finland to enhance soil fertility in heavy clay soils. This
work is on-going and links with soil drainage, cereal production and
further organic waste (boardmill sludge) use in an agricultural setting.
In an urban setting, composting and vermi- composting (using
litter-dwelling earthworms) has been employed and funded through
Lancashire Environmental Fund (Landfill Tax). A current PhD, again jointly
funded by UCLan and the FC, is examining effects of earthworms on tree
establishment at Thames Chase in Essex. This project once more links
trees, reclaimed land, organic wastes and earthworms.
Previous soil restoration operated primarily in terms of the physical and
chemical constituents of the soil and did not consider the structure and
function of biological components. Following major landform corrections,
development of a living soil can proceed once the major components have
been brought together. Constructing soils usually requires the use of a
subsoil and addition of organic matter (OM) which is not new, but the UK
National Building Specifications (2011) now dictate that consideration
should be given to earthworm augmentation or inoculation to enhance
topsoil function. This long-awaited recognition thus takes note of
research undertaken by this group through the development of the EIU
Funded earthworm monitoring has also been undertaken on translocated
grassland at Manchester Airport since 1998 (including £20,000 funding from
Manchester Airport). This followed Runway 2 construction and relates to
the presence of food (earthworms) for legally protected vertebrates
(badgers and great-crested newts). Results from this work have also
influenced the recently commissioned commercial work in Scotland, to be
developed 2012-27, at the Bishopton ordnance development, managed by BAE
Systems (including £3,500 Initial Earthworm Survey).
UCLan staff have been involved in increasing the reach of this research
by involving the public wherever possible. For example, we were involved
in a National Open Air Laboratories (OPAL) campaign. Here, the general
public were encouraged to explore the outdoors and investigate
biodiversity. This was assisted through production of a simple-to-use
field identification guide for earthworms in collaboration with the
Natural History Museum (NHM) in London. This earthworm identification
guide has now been distributed to 50,000 individuals/groups, particularly
school children, and is assisting in production of distribution maps of
the more common species across Britain (something currently lacking). Over
4,200 individual public surveys have been conducted and recorded on line.
Furthermore, English Heritage (Down House in Kent) permitted the ERG to
sample "Darwin's Garden" and have allowed long-term experiments to be
established, replicating those of Darwin (relating to stone burial by
earthworms in Great Puckland's Meadow). This has assisted English Heritage
in providing material on their activities at Down House for public
education. This has also (and will) received much media coverage and links
historic scientific endeavours with current research. Members of the ERG
have also contributed to numerous "Bioblitz" events, where the public are
exposed to biodiversity at selected natural history locations across the
country. These and further aspects of the ERG work have been disseminated
to the public through the media. Most notably two television programmes
have allowed the research to be widely appreciated. The BBC showed a
section on research undertaken in "Darwin's Garden" and a French
organisation (Gedion TV) featured even lengthier exposure of the group in
a documentary entitled "Superworm".
Sources to corroborate the impact
National Building Specifications Ltd,August 2011.
Topsoil and Soil Ameliorants (Q28). http://www.thenbs.com/
This document makes specific reference to earthworm enhancement and inoculation and the
"earthworm inoculation unit" technique developed within this research
group (section 2.23 on pages 4 and 5).
Natural History Museum/OPAL
http://www.opalexplorenature.org/node/2335 : In collaboration with David
Jones from the Natural History Museum (NHM) in London and OPAL (Open Air
Laboratory) an earthworm identification guide has been produced by Lowe
(UCLan). This guide has been distributed free to the public in survey
packs (n=50,000 packs) along with instructions on how to sample for
earthworms. The information from these surveys is being collated by the
NHM to enable distribution maps of common British earthworms to be created
Involvement in public awareness activities
relating to rapid biodiversity assessment in Britain e.g. Lancashire
Bioblitz (June 2011)
Recent television coverage
A 2009 BBC programme "Darwin's Garden" featured Butt relating
recent findings from the ERG to Darwin's original work on earthworm
Ecology, specifically the burying of large stones, at Down House, his home
2) http://www.science-television.com/en/film/1184/super-worm/?producer=4889&PHPSESSID=6e3a9ff4d6416ec96df75f7c11faf1bc A
French production "Superworm" which featured numerous research aspects of
the ERG and extensively featured both
Butt and Lowe.
BOLD (Barcode of Life Database)
The Barcode of Life is a project to create a public collection of
reference sequences from vouchered specimens of all species of life. The
ERG has been instrumental in providing earthworm specimens for inclusion.
British Library Repository for web site During 2009, a request was
received from The British Library to archive the ERG website:
http://www.uclan.ac.uk/erg for the Darwin 200 Collection. This has taken
place and means the ERG will be remembered, for more than publications,
beyond the life of the group.