UK ECN site. North Wyke (latitude 3o 54’ W; longitude 50o 46’N) lies in undulating countryside 7 km to the north of Dartmoor National Park, midway between the villages of South and North Tawton. The site covers 250 ha, of which 200 ha are grassland and 50 ha are deciduous woodland at an altitude of 120 m to 180 m. A lowland grassland site typical of conditions in wetter, western Britain, with predominately impermeable clays of the Culm Measures. ECN is funded through the Rothamsted Long-Term Experiments National Capability (LTE- NCG). Details available at http://www.rothamsted.ac.uk/long-term-experiments-national-capability.