Enhancement of wetland biodiversity through improved water management
Submitting InstitutionOpen University
Unit of AssessmentEarth Systems and Environmental Sciences
Summary Impact TypeEnvironmental
Research Subject Area(s)
Environmental Sciences: Environmental Science and Management
Biological Sciences: Ecology
Summary of the impact
Professor Gowing and his associates' research demonstrated the
sensitivity of grassland species
to soil moisture regime. They developed a method for quantifying the
relationship between plant
community composition and soil moisture regime which showed that
controlling water levels in
traditional ways led to conservation of important plant species and/or
enhanced diversity. This
research led to the Environment Agency issuing practical guidelines to
site managers for these
internationally important sites, with a lead section written by Gowing.
Advice has been given
directly to owners and managers via the Floodplain Meadows Partnership led
by the OU,
engendering parallel studies abroad.
The key insight into declining diversity in floodplain meadows was
recognising that species growing
in diverse communities subdivide the available hydrological niche between
them, thereby reducing
direct competition. This was discovered while undertaking applied research
for river engineering
projects funded by MAFF (now Defra). The new understanding suggests that
no one species
manages to dominate a wet grassland plant community through competitive
exclusion because the
soil moisture environment is so variable, in both space and time. This
variability allows numerous
species to coexist because each is favoured by a particular set of
Our research has quantified the hydrological preferences of many species
and has demonstrated
that their overlap in `hydrological niche space' is significantly lower
than would be expected by
The early stages of this research were published by Gowing with funding
from Defra (formerly
MAFF) and other government agencies (e.g. National Rivers Authority,
English Nature). The key
paper describing the ecological implications of the work was published
from The Open University
by Silvertown, Gowing and colleagues in 1999. This paper challenged the
prevailing neutral theory
of biodiversity and provided concrete evidence for the niche-based
hypothesis for coexistence. It
has been cited over 200 times. Funding from Defra was renewed and a series
of openly available
reports to guide its environmental schemes was produced. The Environment
Agency funded the
production and publication of guidelines for nature conservation managers
in 2004, which are still
regarded as best available information today.
Subsequent projects building on these initial insights have been funded
by the UK research
councils to integrate this understanding with a holistic approach to
floodplain management, by the
Leverhulme Trust to apply the water level control methods developed to
habitats of conservation
importance in South Africa, and by NERC urgency grants to consider the
impacts of major events
(floods or fires) on the responses of the studied communities. Five PhD
students have undertaken
research on applying the new insights to different systems and situations.
The first phase of the work was conducted in a consortium of research
University, The Open University and the Institute for Terrestrial
Ecology/Centre for Ecology and
Hydrology) during the period 1994-99. The more detailed studies undertaken
in 2000-04 were led
by Gowing, then a senior lecturer at The Open University, but still
involving all the partners.
Application of similar methods to sites overseas was funded for 2005-10
(South Africa) and 2008-
10 (Spain). The main dissemination phase of the work started in 2007 with
the establishment of the
Floodplain Meadows Partnership, which still continues today.
References to the research
Papers published in date order:
Gowing, D.J.G., Spoor, G., Mountford, J.O. and Youngs, E.G. (1994)
Requirements of Lowland Wet-grassland Plants, Report to Ministry of
Agriculture, Fisheries and
Food Flood and Coastal Defence Division, London.
Gowing, D.J.G, Youngs, E.G., Gilbert, J.C. and Spoor, G. (1998)
`Predicting the effect of change
in water regime on plant communities' in Wheater, H. and Kirby, C. (eds) Hydrology
in a Changing
Environment, vol. 1. John Wiley & Sons, Chichester, pp. 473-83.
Silvertown, J., Dodd, M.E., Gowing, D.J.G. and Mountford J.O.
niches reveal a basis for species richness in plant communities', Nature,
vol. 400, pp. 61-3.
Silvertown, J., McConway, K., Gowing, D.J.G., Dodd, M.E., Fay,
M., Joseph, J. and Dolphin, K.
(2006) `Absence of phylogenetic signal in the niche structure of meadow
Proceedings of the Royal Society of London, Series B, vol.
273, pp. 39-44.
Rouquette, J.R., Posthumus, H., Gowing, D.J.G., Tucker, G.,
Dawson, Q.L., Hess, T.M. and
Morris, J. (2009) `Valuing nature-conservation interests on agricultural
floodplains', Journal of
Applied Ecology, vol. 46, pp. 289-96.
Araya, Y.N., Silvertown J., Gowing, D.J.G., McConway K.J., Linder
H.P. and Midgley, G. (2010) `A
fundamental, eco-hydrological basis for niche segregation in plant
communities', New Phytologist,
vol. 189, pp. 253-8.
1997-2002: £429,534 grant awarded by Defra (Conservation Management
(Project BD1310) to Dr David Gowing (Cranfield University until March 2000
then Open University)
for a project entitled `The water-regime requirements and the response to
hydrological change of
grassland plant communities'.
2003-04: £17,500 grant awarded by Environment Agency (Anglian Region) to
Dr David Gowing
(Open University) in collaboration with Dr Bryan Wheeler (Sheffield
University) and Owen
Mountford (CEH) for a project entitled `Production of ecohydrological
guidelines for lowland
wetland plant communities'.
2005-07: £84,192 awarded by The Leverhulme Trust to Prof. Jonathan
University) for a project entitled `Soil moisture gradients and the
biodiversity of the Cape Flora'.
2008-13: £205,000 awarded by the Esmée Fairbairn Foundation to Dr David
University) as Floodplain Meadows Partnership co-ordinator.
Details of the impact
The pursuit of pure ecological research into the functioning of
hydrological niches has not only
advanced ecological theory, but has provided practical benefits to
society. It has enabled the
impacts of water abstraction on sites of conservation interest to be
objectively assessed, water
management of nature conservation sites to be based on scientific
knowledge, and both the
practitioner community and interested members of the public to understand
how climate drives the
species composition of wet meadows.
The need to designate and manage the few surviving remnants of
species-rich wet grassland in
England was recognised in 1973. Numerous sites were subsequently
designated and managed for
their nature conservation importance. Initially, presumably because they
were labelled `wet
grasslands', their managers strove to retain water on them by building
bunds and blocking ditches.
This mindset was reflected in the management prescriptions of
agri-environment schemes in which
landowners were paid to raise water levels. Against this background, our
unexpected results (e.g. Gowing et al., 2002). The evidence was that
species richness in these
systems was greatest where drainage was at its most efficient. Further
research confirmed these
findings (e.g. Gowing et al., 2005) and allowed specific advice to be
produced for people wishing to
conserve particular features of nature conservation interest.
Specifically, the pattern of water
availability over the year could be prescribed to favour a particular
species or community of
interest. Often this practice involved holding water tables as high as
possible during summer, but
low enough to drain excess water in winter and spring.
The research team at The Open University regularly advised organisations
such as the
Environment Agency (EA) and Natural England (NE) on a site-by-site basis
during the period
2000-05 (e.g. outputs 5 and 8 below.) During this period the EA identified
the need for general
guidance to all managers of wet grassland of conservation interest. It
formally commissioned a
publication entitled `Ecohydrological guidelines for lowland wetland plant
communities' in 2004 and
approached The Open University to write the lead section on grasslands.
The effect on the ground
of this work was to alter the mindset of managers to the extent that where
they had previously built
bunds and blocked ditches on sites of nature conservation importance, they
were now removing
bunds and clearing ditches to safeguard the biodiversity of their sites
(e.g. culverting and bund
removal works at North Meadow Special Area for Conservation (SAC),
Cricklade, Wilts.). The
guidelines have become a standard reference work for wetland managers and
the EA paid for
them to be updated in 2010.
Another route to impact was advice given to the EA on the appropriate
assessments it needed to
undertake on sites designated as SACs under the European Habitats
Meadows were designated under this directive and The Open University team
produced a series of
reports (e.g. outputs 4 and 7) to identify the risks posed to these sites
from external influences. The
EA recognised that many of its Area Offices were commissioning similar
advice and therefore
suggested The Open University host a national project in partnership with
a range of relevant
organisations to coordinate the monitoring, analysis and communication of
information relating to
floodplain meadows. The Floodplain Meadow Partnership was therefore set up
in 2007 and since
then has proactively interacted with practitioners to implement the new
understanding arising from
our group's research.
Since 2007, The Open University has worked in partnership with seven
other organisations (see
list of contacts below for details), all of which are involved in the
conservation of this threatened
habitat. The partnership, hosted by The Open University, and funded by
seeks to support practitioners within the member organisations and beyond
via an interactive
website, regular newsletters, workshops, field visits, guided walks,
public lectures and a
conference. The workshops are aimed at site mangers, who are taught
practical skills allowing
them to assess their own sites and amend their management to enhance
biodiversity. Over 100
managers have been trained in this way, representing the majority of
people managing designated
sites in this category.
Since 2008, the research team has visited 93 sites across England and
Wales both to gather data
and to provide advice. Many of these have had their management altered in
response to the
evidence provided by the earlier research, including all five of the sites
designated as being of
international importance under the Habitats Directive. In seven cases
drainage channels were
reinstated to facilitate removal of flood waters, which avoided species
loss through episodes of
anoxia. The Partnership is the first point of contact for people with
questions about the
management of floodplain meadows; we have over 650 people requesting our
had over 2500 unique visitors to the interactive website and have reached
over 8000 people at
face-to-face events over the past six years. Feedback received from
participants describes how
they have altered practices, such as cutting dates, following their
interaction with the University
Sources to corroborate the impact
External sources corroborating impact:
- Gowing, D.J.G., Tallowin, J.R.B., Dise, N.B., Goodyear, J., Dodd, M.E.
and Lodge, R.J.
(2002) `A review of the ecology, hydrology and nutrient dynamics of
floodplain meadows in
England', English Nature Research Report 446, Peterborough.
- Gilbert, J.C., Gowing, D.J.G. and Youngs, E.G. (2000) `Blackwater
Valley SSSI: Hydrological
investigations and management recommendations to conserve MG5 grassland
communities', Report to English Nature (Thames and Chilterns Team,
- Gowing, D.J.G. (2000) `Impact of various abstraction scenarios upon
North Meadow SAC',
Report prepared for the Environment Agency (Thames Region), Wallingford.
- Gowing, D.J.G. and Youngs, E.G. (2005) `The requirements of Apium
repens - an
ecohydrological assessment', Report to the Environment Agency (Thames
- Gowing, D.J.G., Lawson, C.S., Barber, K.R. and Youngs, E.G. (2005)
grassland plant communities to altered hydrological management', Final
report to Defra
(Conservation Management Division), London, Project BD1321.
- Gowing, D.J.G., Lawson, C.S., Youngs, E.G., Barber, K.R., Prosser,
M.V., Wallace, H.,
Rodwell, J.S., Mountford, J.O. and Spoor, G. (2002) `The water-regime
requirements and the
response to hydrological change of grassland plant communities', Final
report to Defra
(Conservation Management Division), London, Project BD1310.
Beneficiaries who could be contacted to corroborate impact:
- National Conservation Advisor, Environment Agency, Bristol
- Head of Wetland section, Centre for Ecology and Hydrology, Wallingford
- Head of Biodiversity, Field Studies Council, Shrewsbury
- Senior Ecologist, Footprint Ecology, Wareham, Dorset
- Water for Wildlife Project Director, The Wildlife Trusts, Newark