Snowdonia National Park covers 823 square miles

That is recommended in a report on their future for the Welsh Assembly Government.

The three parks, Brecon Beacons, Pembrokeshire and Snowdonia, cover more than 20% of Wales.

They are governed by independent authorities with members appointed by the assembly or nominated by local county councils.

But the review says that system should change.

The report looked at the role of the parks and considered their contribution to sustainable development.

The importance of the national parks as national assets cannot be overstated John Lloyd Jones, Countryside Council

It also examined how the parks could influence the communities within its boundaries and beyond.

Despite their size, the parks are home to just 2.9% of the population.

John Lloyd Jones, Countryside Council for Wales chairman, said: "The importance of the national parks as national assets cannot be overstated.

"The environment contributes nearly �9bn to the Welsh economy each year.

"The environment is seen at its very best in our national parks, supporting many rural services and communities."

One of the main issues arising from the report was the selection of candidates to the national park authorities.

The method of inviting and selecting people for appointment by the assembly government was seen to deliver a "high calibre of competence".

However, the system where by members of the local authorities were nominated to the national park authorities was criticised.

The report found members were often selected on the basis of availability rather than on an "interest in the national parks or a willingness to work within the guiding principals".

The authors of the report say they favour direct elections in future.

But that is a move which would require a change in the law and a lot of discussion before it happens.

In Pembrokeshire recently county council members have been accused of following council policy rather than the interests of the park by supporting the Bluestone holiday village development.