Dr Tim Reed explains how reedbeds – large or small - play a vital role in improving the biodiversity of the Great Ouse Valley.

Look back a couple of centuries and there were large tracts of wetlands and reeds and rushes were commonplace on roofs and in houses.

Now, however, sustainable local craft industries for roofing and rush mats have almost disappeared as their source materials have declined.

The same fate has threatened the plants and animals associated with the wetland habitats.

The once expansive blocks of wetland throughout the valley have been drained and converted to agriculture. With them the old lines of reeds along the river have gone.

Reeds and rushes are found only here and there, rather than swaying in the wind throughout the region.

So instead of rushes, reeds and sedges connecting small and large areas of wetlands, they are now mainly found isolated in large, managed nature reserves, developed from areas previously used for gravel extraction.

More recently, concentrated efforts at places such as Ouse Fen at Earith have seen planned gravel extraction, and subsequent planting and directed management.

This has produced reedbeds and pool systems that mimic many of the areas lost over the last few centuries.

We are now seeing the return of wintering bird species in numbers long since absent, and reedbeds are ringing to the boom of Bitterns and calls of Cuckoo in summer.

Big wetlands have their place, but in nature, as in our daily lives, the small areas have their place too.

Small reedbeds, such as that found on Holt Island in St Ives, are playing their part in supporting a range of birds, insects and mammals across the year.

In summer, the reserve has warblers, dragonflies and damselflies, and in the Autumn and winter, finches and buntings.

Carefully managed, the reedbed supports a diverse plant and animal community year-round.

Places like Holt Island play an important role in providing stepping stones up and down the valley for otters, birds and butterflies.

And that little reedbed is home to Reed and Sedge Warblers that return each year after a 6,000 km return journey: small can be beautiful too.