HILL farmers should be paid to protect water quality, wildlife, carbon stores and upland landscapes, the National Trust has said.

The conservation group said upland farming would change radically over the next decade and, where once farmers concentrated on producing meat, the Trust said in the future they may focus on farming in other ways.

Costs of production and falling returns from sales are currently hitting upland farmers hard, but in the coming years payments will be linked to how farmland is managed for the benefit of society, the Trust said.

Speaking on the 10th anniversary of the Trust's purchase of the Hafod y Llan hill farm in Snowdonia, Iwan Huws, the National Trust's director for Wales, said: "Ten years ago any notion that hill farmers would farm for water or carbon would have been dismissed as fantasy.

"But with the pressures of a changing climate and the need to protect and value our natural capital, the future of hill farming will focus on a mixture of food production and providing wider environmental benefits for society."

The National Trust said better use of existing funds, as well as new investment, was needed to help farmers protect the uplands' natural resources and landscapes.

For example, public money, such as flood management funding, could be redirected so farmers could manage the land to reduce flood risk through restoring natural river courses.

Ian Johnson, spokesman for the NFU in the South West, said he backed public funding and support for hill farmers as long as it did not come with so much red tape that farming became "impossible".

He said the "public goods" hill farmers delivered should be recognised and the problems they faced needed to be addressed. However, he said he would take exception with the National Trust if their proposals meant hill farmers "fundamentally changing their practices".

He said: "There are too many fingers in the pie, too many people telling farmers what they need to be doing."

He added: "We can't have farmers being treated as park keepers."

The current Hill Farm Allowance (HFA) is being replaced from 2010 with an uplands version of the environmental stewardship payments, which reward farmers for managing their land in a way that benefits wildlife and landscape.

Last week the Exmoor Society and the Dartmoor Preservation Association met ministers and officials at Parliament to raise concerns over the plight of hill farmers in their areas.

Rachel Thomas, chairman of the Exmoor Society, said hill farmers were facing significant challenges because of a reduction in public support schemes.

She said this was threatening the public benefits provided by wild landscapes, access and natural resources.

The groups called for changes to simplify the agri-environmental scheme which will replace the HFA to make it more accessible to farmers, and said in the long term a system of "public payments for the provision of public goods" should be introduced.

A spokesman for the Department for Environment, Food and Rural Affairs said: "Defra has committed to rewarding hill farmers for the environmental and landscape benefits they provide through the replacement to the Hill Farm Allowance from 2010."