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Research at the Open University

Tadham Moor
Nutrient addition trials at Tadham Moor, Somerset. (Photo Credit: Carly Stevens)

PROFESSOR David Gowing has been researching the eco-hydrology of floodplain meadows for 18 years.

Research papers and documents

A list of Professor Gowing’s published work is available. Some are available on line through Open Research On-line, the Open Universities research access facility.

Major areas of research within the department are highlighted below with links to relevant documents where available. Further documents can also be found in under information and news/useful documents.

Water Regime Requirements of the Native Flora with particular reference to ESA's (1997)

If water levels in Environmentally Sensitive Areas (ESAs) are to be managed effectively for nature conservation objectives, then quantitative information relating to the water-regime tolerances of vegetation is required. In order to provide this information, the relationship between species distribution and the long-term prevailing water regime needs to be understood with considerable precision. The information must also be in a form which is transferable between sites.
To identify the water-regime tolerances of species, data were gathered from areas of species-rich lowland wet grassland throughout England. A total of 2,393 microsites were sampled, each consisting of a 1 m2 quadrat of grassland, and treated as independent observations. At each, the species complement was recorded and the water regime during the previous 10-20 years was modelled.
Water Regime Requirements of the Native Flora with particular reference to ESA's

Water Regime Requirements and Response to Hydrological Change of Grassland Plant Communities (2002)

The Water Regime Requirements and Response to Hydrological Change of Grassland Plant Communities (2002) was an appraisal of botanical data from 18 sites across England supporting species rich grassland. At each site between 60 and 800 botanical positions were surveyed (total 3904 sets of data). The water regime of each botanical position was modelled and validated against dipwell observations.

Water regime was found to be one of the most important determinants of plant community composition and a range of water regimes for each community type was presented.
Ranges of phosphorus regimes were also presented and the data suggested that phosphorus levels were critical in determining community composition, whilst other soil chemistry measures did not appear to be significant.

Results are presented that summarise changes in plant communities following deliberate change in water regime.
The work was commissioned to advise Defra policy with respect to Agri-Environment scheme design.
The Water Regime Requirements and the response to Hydrological Change of Grassland Plant Communities (BD1310)

Parts of this project were extended and reported on in 2005. This additional report, which should be read in conjunction with the above, is available here:

Response of grassland plant communities to altered hydrological management (BD1321)


Impact of summer flooding on floodplain biodiversity via nutrient deposition (NERC Urgency NE F009232 report) Prof David Gowing, Open University

The fluvial floods of June/July 2007 were some of the largest on record in the UK. They deposited substantial amounts of sediment across floodplains and thus raised questions about whether floodplain habitats would be impacted by eutrophication through phosphorus enrichment. In particular, did summer floods deposit sediments with high phosphorus content due to waste-water treatment works being overwhelmed by intense rainfall? In total, 100 samples of sediment, soil or hay were analysed to estimate the amount per hectare of total phosphorus, available phosphorus and basic cations delivered as sediment following a substantial summer flood, to assess the importance of the summer-flood delivered sediment in the context of a floodplain grassland's nutrient budget and to assess the likely impact of higher frequency summer flooding on the biodiversity.

Impact of summer flooding on floodplain biodiversity via nutrient deposition (NERC urgency report)

Where are my quadrats? Positional accuracy in fieldwork. Methods in Ecology and Evolution. Dr Mike Dodd, Open University (2011)

1. There has been much written about sampling design, spatial scale and the need for permanent plots in long-term monitoring but very few authors have considered how to locate and re-find positions in the field accurately. Indeed, many attempts at re-sampling exact positions set up many years previously have failed.

2. Various field measurement systems were compared including 50-m tape, consumer-grade GPS, total-station theodolite and differential GPS.

3. Both total station and differential GPS were able to measure and relocate quadrats accurately to within a few centimetres over distances of hundreds of metres or more.

4. Of over 5001 × 1 m vegetation monitoring quadrats set out and location re-recorded by differential GPS at sites across UK, only 1% had positional errors of more than 0·2 m. None of these quadrat locations relied on permanent markers. Differential GPS has the advantage of speed and delivering coordinates in latitude/longitude or local coordinate system directly.

5. Accurately located quadrats can be resurveyed many years in the future just using the original coordinates without worrying about ‘permanent’ markers that rarely turn out to be truly permanent. If more researchers used these techniques, then there is huge potential for establishing networks of accurate long-term monitoring positions, which could provide information on a wide range of topics, such as vegetation dynamics and environmental change even if these were not the original research objectives.

Non-chemical control of marsh ragwort (PhD, Ellie Sargent)

Marsh ragwort Senecio aquaticus can be a common plant of wet grassland, usually occurring in unimproved wet hay meadows but it can also occur in more improved wet grassland. It is not so toxic to livestock as other ragwort species but can still cause problems for livestock farming.

However, in many situations, using herbicides to control marsh ragwort is not appropriate as this could destroy the flower-rich meadows. The Open University recently carried out a study commissioned by the RSPB and Natural England into how marsh ragwort abundance can be reduced through implementation of some commonly used farming practices. This work was carried out by Ellie Sargent as part of a PhD study into the non-chemical control of Marsh Ragwort. It is not yet published but a leaflet is available.

Restoration of wet grasslands through re-instatement of surface surface grips (2006-2007) (Defra) With David Gowing – Open University and Mike Acreman - Centre for Ecology and Hydrology, Wallingford & Dorset

This project looked at the contribution of grip installation (i.e. shallow drainage channels) to restore species-rich wet grasslands on previously intensively-farmed sites. We assessed this through study of the impacts of spatial and temporal distribution of in-field wetness following installation of grips as well as the change in plant species composition. We tried to relate changes in soil penetration resistance as a result of differences in soil moisture.

Influence of soil water regime on nitrogen availability and plant competition in wet meadows (2001-2005) (PhD project – OU Research Development Fund) With David Gowing – Open University and Nancy Dise – Manchester Metropolitan University

This project looked at how environmental factors (i.e. water regime and soil nitrogen availability) influence plant competition and species richness in wet meadows. Inter-relationships between the above factors as well as cause-effect relationships were investigated. This study is particularly important for conservation of such ecosystems, which have suffered as a result of agricultural intensification among other causes

Interactive effects of Nitrogen deposition and climate change in floodplain meadows Dr Carly Stevens, Leverhulme Research Fellow, The Open University and Lancaster University Stevens, c.stevens@lancaster.ac.uk / 01524 593937

The potential for atmospheric nitrogen deposition to impact on neutral grasslands has been demonstrated on several occasions but N deposition does not occur in isolation. This project, funded by the Leverhulme Trust, is investigating how nitrogen deposition is interacting with drought and flooding to impact on species composition and soil chemistry. The study uses intact cores in mesocosms.

Recovery from N application in a floodplain meadow Dr Carly Stevens, Leverhulme Research Fellow, The Open University and Lancaster University c.stevens@lancaster.ac.uk / 01524 593937

This investigation utilises a long running nutrient addition experiment at Tadham Moor, Somerset. Nitrogen addition was finished on the experiment a number of years ago and this project is investigating how the meadow has recovered since applications ceased. The project is investigating the impact on both the vegetation community and soil chemistry and is funded by the Leverhulme Trust.

Biodiversity of European grasslands – impacts of atmospheric nitrogen deposition (BEGIN) Dr Carly Stevens, Leverhulme Research Fellow, The Open University and Lancaster University c.stevens@lancaster.ac.uk / 01524 593937

The BEGIN project is a large ESF funded collaborative project bringing together research partners from France, Germany, Netherlands, Norway and the UK. The project has conducted surveys of acidic and calcareous grasslands, analysed historical data sources and established experimental sites in Wales, Norway and France.

Collation of evidence of nitrogen impacts on vegetation in relation to UK biodiversity objectives Dr Carly Stevens, Leverhulme Research Fellow, The Open University and Lancaster University c.stevens@lancaster.ac.uk / 01524 593937

Jointly with CEH and BSBI this project is working towards identifying indicators of Nitrogen deposition. This project is using national vegetation data sets, such as those collected by Plantlife, BSBI and the British Lichen Society, to identify indicators of nitrogen deposition at a large scale. The work is funded by JNCC.