text: ROMANTIC WALKS through thick carpets of autumn leaves may lose their charm if a theory put forward by a Cardiff biologist is accepted. For Mr Brian Ford, a fellow of University College, Cardiff, believes the season of mists and mellow fruitfulness is also the time when trees get the urge to clear their systems and relieve themselves.
  Mr Ford’s theory, published in this week’s edition of the scientific journal Nature, explains two of the enduring mysteries of biology - why plants drop their leaves and why all living beings except plants excrete. According to Mr Ford, when in autumn leaves turn red, yellow and brown, they are being filled with products no longer required and are then quietly dropped.
  The mystery of why leaves fall has occupied Mr Ford on-and-off since his school days. He said the traditional explanation is that if plants did not get rid of their leaves they would be damaged by the change in the weather. But he was not satisfied with this idea as some plants, ever-greens, do not shed leaves in autumn but continuously throughout the year.
  PUZZLED
  He was still puzzled. "Their is no reason why they should do this. In fact, if seems a total waste of time. After all, we don’t drop fingers off all the time." The accepted view is that hen leaves yellow they ar growing old and dying. But Mr Ford says this is “codswallop” as the leaves are only six months old and the yellowing leaves are breathing more, rather than less, than green leaves. He said a Canadian maple tree near his Cardiff home is iridescent red and has so much pigment it is almost black. He believes the colour is there for a purpose and comes, in fact, from excreted products.
  Earlier this year, it suddenly dawned on me that these two mysteries fitted together,” said Mr Ford yesterday. He expounded his theory for the first time at this year’s Inter Micro convention of microscope users in Chicago, where he received a standing ovation.
  He has since discussed it in several countries with many of the most eminent people in the field and no-one has yet suggested it is wrong. Mr Ford said schools may have to rethink their biology lessons and that other ideas may need to be reconsidered. He said, “I really don’t want to take any of the drama, the majesty and aesthetic pleasure out of picking up leaves but if you look at a tree surrounded by brown, decomposing leaves it does look as if the theory could be correct.”