THE iconic two and a half mile beech avenue near Wimborne is nearing the end of its natural life.

The avenue contained 731 trees when William John Bankes planted them in 1835 as the main driveway to the house at Kingston Lacy.

But time has taken its toll and National Trust staff believe that in less than 20 years, the avenue will be gone.

Nigel Chalk, National Trust gardens and countryside manager, said: "Beech trees planted in chalky soil are expected to live between 150 and 200 years.

"Age, disease, shallow roots and climate change are all contributing to the decline of the avenue. Sadly, we have to recognise that it has very little future.

"We do what we can to keep a tree viable by carrying out surgery, but eventually we have to make a decision to fell it. With a busy road running down the middle of the avenue, we have no other choice - we have to consider public safety."

A second avenue planted further back from the road 20 years ago by public donation has not done as well as was hoped, partly because it had to share light with the more established trees.

The National Trust has launched a year-long celebration of the Kingston Lacy estate beech avenue, and want people to share their memories of the avenue.

Landscape photographer Charlie Waite is running a series of photographic master classes on behalf of the National Trust, for the public to capture images of the beech avenue, for a Kingston Lacy display in April 2009.

People who donated money for replacement trees are being asked to get in touch with the National Trust, who are reviewing options for alternatives later this year including a replacement avenue.

Get in touch with the Kingston Lacy estate, or contact Charlie Waite via landandlight.co.uk