ONE of the most important areas of natural floodplain wetland in Britain has become Scotland's latest national nature reserve.

Insh marshes, covering about 2000 acres of floodplain between the villages of Kincraig and Kingussie, is home to an impressive range of wildlife including lapwings and hen harriers. A total of 209 species of birds have already been recorded on the marshes.

RSPB Scotland, which owns the land, welcomed the award but called on the Scottish Executive to increase investment in NNRs to preserve them for future generations.

The award by Scottish Natural Heritage is seen as recognition of the area's beauty and environmental significance.

Insh marshes are one of the few natural floodplains in Britain where the river Spey floods the area several times a year. As the marsh holds and releases the water gradually, like a sponge, it protects downstream areas, such as the Aviemore area, from flooding and keeps the surrounding farmland fertile.

It boasts seven ''red list species'' which are birds of high conservation concern. They include, grey partridge, reed bunting and bullfinch. It is a nationally important site for breeding osprey and waterfowl.

Half the entire population of breeding goldeneye in the UK uses the marshes.

There are also many species of invertebrates on the marsh, and the meadow has more than 500 species of plants.

Insh marshes brings the total number of NNRs to 74, including Beinn Eighe in Wester Ross, the island of Rum, Loch Lomond and the Isle of May, although the designation of 18 are currently being reviewed. Scottish Natural Heritage is also now embarking on a major programme to make all the NNR's more accessible to the public.

SNH awarded the Insh NNR in recognition of the area's internationally important natural heritage, the significance of the marshes for recreation and public enjoyment, and the sensitive management of the marshes by the RSPB and the local communities over many years.

The area is already a site of special scientific interest, a special protection area for osprey, a special area of conservation and a Ramsar site for its variety of wetland habitats and rare species of plants and animals.

At the launch ceremony, John Markland, the SNH chairman, said: ''I am delighted to welcome Insh marshes as our newest national nature reserve.

''Set within Scotland's newest national park in the Cairngorms, Insh marshes joins the likes of St Kilda, Glen Affric and Staffa, as an exceptional place where the outstanding natural heritage of Scotland can be managed and promoted for the enjoyment of people and for the conservation of nature.

''The declaration of the NNR is also an accolade for the care that the people of Kincraig and Kingussie have shown to the area through the years and also for the RSPB, who own the area, for their sensitive management.''

Lord Jamie Lindsay, chairman of the RSPB Scotland, said: ''We welcome the declaration of Insh marshes as a national nature reserve. This recognises the importance of the reserve as a special place for nature, and our role in caring for the area over the years in partnership with the local community.

''The timing is also significant for us as RSPB first acquired the reserve in 1973 so this year marks our 30th anniversary of involvement in the reserve.''

Nic Bullivant, local ranger and recent chairman of the Kincraig Community Council, said: ''Insh marshes is a significant part of our local communities. We realise the quality of our area's environment, and it seems only proper for this to be recognised at the highest level.

''The approach of the two large conservation organisations, SNH and RSPB, in involving the local community in this declaration is very much welcomed. I hope they continue to involve local people in enjoying what the reserve has to offer for many years to come.''

Fiona Murray, RSPB Scotland's conservation policy officer, said: ''The executive should back further protection for such sites and encourage more sustainable floodplain management in the rest of Scotland.''