The ECN Data Centre

Site Information: Wytham

Sponsoring organisation(s)

Natural Environment Research Council & University of Oxford (through UK Centre for Ecology and Hydrology)

Network(s) this site belongs to
UK Environmental Change Network
UK Environmental Change Biodiversity Network

Site characteristics

Min Altitude 60m

Site boundaries are indicated with a black line.
Click map to enlarge.

Max Altitude 165m
Area of Site 770ha
Mean annual temperature* 10oC
Mean annual rainfall* 738mm
* calculated from the ECN Data Centre database
Information held about this site
View a list of datasets collected at this site
View a list of publications about this site


The whole site is encompassed by a loop of the River Thames, 5 km north west of Oxford. The site comprises of 400ha of SSSI designated woodland, and 370ha of organic mixed farmland.

The altitude ranges from 60m on the river flood plain to 165m at the top of Wytham Hill. A change in geology and soil type parallels the topography with alluvium beside the Thames overlying Oxford Clay. Away from the river, the clay is exposed with a large area of deep, heavy soils which are often waterlogged in winter. Towards the top of the hill there is a thin band of sandstone, giving rise to sandy soil in places and the very top of the hill is composed of coral rag limestone covered by extremely thin, well-drained soils.

The woodland at Wytham can be divided into three broad categories of roughly equal area: ancient, secondary and plantation. The ancient woodland has never to our knowledge been cleared and there has been continuity of tree cover since the prehistoric 'wild wood'. It has however had a long history of management, which for many hundreds of years took the form of coppicing. Although this was abandoned in the early twentieth century, the characteristic growth form is still clearly visible. The secondary woodland has grown up naturally in the last 200 years or so, after the abandonment of wood pasture, pasture or cultivation. The National Vegetation Classification places both ancient and secondary woodland in community W8, Fraxinus excelsior - Acer campestre - Mercurialis perennis woodland. Neither of these woodland types are actively managed today. The oldest plantations are beeches of approximately 200 years old, but most are 50 - 60 years old. Within the woodland there are patches of semi-natural grassland, of both ancient and recent origin, and scrub.

The farm is mainly extensive grassland managed under the Upper Thames Tributaries Environmentally Sensitive Area Scheme and Countryside Stewardship, with some arable land, interspersed with hedgerows and some small wetland areas.

Oxford University has owned the Estate since 1943 and many pioneering studies in ecology have been carried out. Long-term records exist on many topics, in particular on birds, small mammals, and badgers. Nearby, the Radcliffe Meteorological Station in Oxford possesses the longest series of temperature and rainfall records for one site in Britain. Wytham was a flagship site for NERC's Terrestrial Initiative in Global Environmental Research (TIGER) programme.

ECN terrestrial monitoring has been carried out at Wytham since 1992, with additional research done on the impacts of drought on grasslands and woodland vegetation and stream water chemistry, canopy tree ecophysiology, forest microclimates, and the impacts of deer on woodland vegetation.

Centre for Ecology and Hydrology


Related links

  • Photographic Archive of Wytham: Each week a digital photo of Wytham is taken and kept in an archive as a record of conditions at the site.
  • This site is part of the Rural Heavy Metals network.
  • This site is part of the COSMOS-UK network. COSMOS (the Cosmic-ray Soil Moisture Observing System UK), is a new network that will deliver real-time weather monitoring and field scale measurements of soil moisture across the United Kingdom.



Steffi Schafer & Denise Pallett

UK Centre for Ecology and Hydrology
Maclean Building, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB &

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