Conservationists said the problem of teenagers chasing cattle grazing on a Norwich meadow has been resolved by a combination of warnings, education and community action.

A notice was posted at Cary's Meadow, off Yarmouth Road in Thorpe St Andrew, last month, warning that cows were being harassed and that the police had been informed.

The small herd, including calves, are being used to graze the area, controlling the vegetation in a way which encourages the growth of wild flowers and maintains important natural habitats.

The meadow is owned by the Broads Authority, but managed by the Norwich Fringe Project, whose project officer Matthew Davies said the cattle-chasing problem had now stopped, with the help of people living nearby.

'It was just kids at the end of the summer holidays who were a bit bored and came down here, saw the cows and didn't understand, so they decided to chase them around,' he said. 'It might have been fun for them, but it was not fun for the cows which can get very stressed.

'Since I put the sign up, people have been fantastic in reporting it, and without local people taking an interest we wouldn't have resolved the problem so quickly.'

Paula Hughes, project assistant, said she had previously caught some children chasing cows on a similar site. 'We just explained that this was a very heavy and fast-moving animal to be chasing, and it could be very dangerous,' she said. 'We talked about the cows and educated them about their behaviour and by the time we finished they stayed with us to learn some more, so it was really positive.'

Cary's Meadow was a traditional grazing marsh alongside the River Yare for many years before it became used as a dumping ground for building materials, which was later covered with a thin layer of topsoil. The resulting mix of grassland habitats now supports 22 acres of varied plants.

Grazing by cattle for a short period each year is enough to prevent the scrub from encroaching and ensures the meadow maintains its diversity, such as the orchids which have appeared since the cattle began their work.

Mr Davies said: 'They are like our lawn-mowers. You need low nutrients for wild flowers, which is the opposite to what you would want in your garden. If you cut the grass by machine you would have to collect the leftover material to stop the nutrients going into the system. If the cows are eating the grass, it stops the nutrients getting through, and they recycle it through their system into cow pat which provides habits for insects, so it becomes another ecosystem in itself.'

The cows are owned by Michael and Colin Rounding, who farm at Shotesham, south of Norwich. The meadow includes signs giving advice on safeguarding the animals, including to keep dogs under close control and to avoid getting between and cow and her calf.