1. Somerford Mead: drivers of species’ change: management, climate or chance? Dr. Alison W. McDonald The Department of Plant Sciences The University of Oxford

2. The location of Somerford Mead adjacent to the river Thames and of the nearest floodplain meads. Re-created sites now lie to the east and south of Somerford Mead.

3. The Experiment After a seed bank study in 1985/6 showed that no seeds of meadow species remained in the soil, seed was harvested from Oxhey Mead, Yarnton in July/Aug 1986. The seed was broadcast in Somerford Mead in September 1986. Null Hypothesis: the treatments - aftermath grazing, by sheep by cattle and no grazing - have no impact on the frequency values of each species recorded.

4. Emorsgate Seeds harvester on Oxhey Mead.

5. Annual grasses and herbs germinated in Somerford Mead the first year. The sward was >1 m tall.

6. The arrangement of plots with their treatments on Somerford Mead. S = sheep grazed; c = cow grazed; u = ungrazed.

7. By May 2005 a cow-grazed plots looked like this and young plants of Sanguisorba officinalis were recognized.

8. Quarterly rainfall at the Radcliffe Meteorological Centre, Oxford, 2000 – 2010.

9. Species scores in Somerford Mead 2001-2011

10. This table shows the different frequencies of each species recorded in 2013, according to management regime. Note: some species respond more to climate than management e.g. Carex hirta scores Ellenberg F7; Leucanthemum vulgare scores F4 S = sheep-grazed; C = cow-grazed; U = un-grazed Most abundant species/treatment sheep-grazed plots 2013S 2013C 2013U cow-grazed plots 2013S 2013C 2013U ungrazed plots 2013S 2013C 2013U 1 Agrostis stolonifera 2925812 Centaurea nigra 2124821 Arrenatherum elatius 6829 2 Anthoxanthum odoratum 116313 Lathyrus pratensis 17224 Dactylis glomerata 303347 3 Bromus commutatus 26222114 Leontodon autmnalis 933523 Festuca rubra 536382 4 Carex flacca 24112115 Lolium perenne 42493324 Holcus lanatus 452961 5 Carex hirta 5329 16 Plantago lanceolata 47824025 Potentila reptans 10 19 6 Cynosurus cristatus 4034617 Ranunculus acris 59615226 Hordeum secalinum 151618 7 Rumex acetosa 2614818 Rhinanthus minor 30271 8 Trifolium repens 46321819 Taraxacum officinale 51 33 9 Lotus corniculatus 122020 Trifolium pratense 476639 10 Ophioglossum vulgatum 1715 11 Elytrigia repens 1248

11. These species scored 5 or less overall. Note: 2 Brach pin and Meli uni may originate from Wytham Wood; Prim veri is frequent in patches but not in the recording plots. 1 Agrostis capillaris 2 Anthriscus sylvestris 3 Brachypodium pinnatum 4 Bromus Sp. 5 Calliergon cuspidatum 6 Cerastium fontanum 7 Cirsium disectum 8 Crataegus monogyna 9 Crepis biennis 10 Daucus carota 11Fagus sylvatica 12 Festuca pratensis 13 Festuca ovina 14 Melica uniflora 15 Medicago lupina 16 Persicaria amphibium 17 Persicaria polygonum 18 Potentilla erecta 19 Primula veris 20 Prunus spinosa 21 Rumex obtusifolius 22 Trisetum flavescens 23 Veronica serpyllifolia

12. First Fritillaries seen in Somerford Mead, April 2015.

13. Over 1,000 years of management for hay followed by grazing is beneficial to bees (at least 4 species) and many other invertebrate animals, birds and small mammals.

14. FINALLY Ben Woodcock (CEH) using my plant data and his plant and invertebrate data, has suggested that it is likely to take between 70 and 100 years for the community in Somerford Mead to resemble that of Yarnton Meads. Somerford Mead is now of international importance for its long annual data set, 1987 – 2014, and the accompanying descriptive papers.

15. ACKNOWLEDGEMENTS I would like to thank the University of Oxford Department of Plant Sciences, the Centre for Ecology and Hydrology, Wallingford, and Farm Animal Initiatives for their support.