I didn't vote for Boris. But because the spirit of fair play seeps from the very pores of this column, I shall pay a tiny homage to London's new Mayor. In one respect he has made a good start. Last week, he planted a tree.

OK, he has some way to go to fulfil the most eye-catching of his election pledges. In what was presumably an unconscious echo of Chairman Mao's “let a thousand flowers bloom”, Boris promised 10,000 new trees in the capital under his leadership. But (as Mao also said) every journey must start with a first step. And few journeys in London are more vital than this drive to reverse the decline in its stock of trees.

Some 40,000 have been felled by London's axe-happy boroughs in five years. According to a London Assembly report, 40 per cent of these murders were initiated by insurance companies. Yet the report found that just 1 per cent were justified. When houses start cracking - usually because they are built over 150-year-old sewers on shifting clay - it's too often some innocent tree, unable to speak in its own defence, that becomes, literally, the fall-guy.

But this isn't just a London trait. Britain has lost millions of trees in my lifetime. True, not all were felled by man. The Great Hurricane of 1987 - when nature massacred nature, snapping stout sycamores like twiglets - destroyed 15 million trees in five hours. Walking through our local park the next morning was one of the most heartbreaking moments of my life. (True, I've had a pretty easy life.)

Then there are those fungal illnesses that seem to curse our trees every decade. In the 1980s it was Dutch elm disease, killing 23 million British elms. Then came a mysterious ailment (perhaps related to climate change) called oak decline, which withers oaks from the top down. Now half our conker trees are raddled with something called “bleeding canker disease”. It sounds ghastly, and is. First the horse chestnuts get running sores. Then they die. It's the arboreal equivalent of the Black Death.

Even so, the British tree's worst enemy remains the British people. Or, to be more specific, the developers who tear down magnificent oaks standing on ground that could be more “profitably” occupied by a new supermarket. And house-owners who would have a nicer view from their upstairs windows if only those annoying poplars could be uprooted. And, of course, local authorities that have gone health-and-safety bonkers. Perhaps they will behave better now that threatened trees are protected by a public-benefit valuation called “Cavat” (Capital Asset Value for Amenity Trees). But that initiative strikes me as being too little, too late. Recently the London Borough of Islington condemned a row of pear trees because the risk of fruit dropping on passers-by was deemed unacceptable. Norwich Council similarly took an axe to 20 horse chestnuts, because of the “danger” of falling conkers. It's mad. If such nannies had been around in the 17th century the apple would never have been allowed to fall so close to the mighty bonce of Newton, and mankind wouldn't have discovered gravity. Well, not for a few more years, anyway.

The irony is that trees are good for our health. They generously suck the fumes out of the city air for our benefit. That was why London's plane trees were planted in the first place. In the late 19th century they were the only things capable of combating the foul, lung-clogging smogs. It's the same today. Researchers at Columbia University have just published a paper highlighting the noticeably lower incidence of asthma among children living on tree-lined streets.

Trees also play a huge part in our psychological wellbeing. That's especially true now, in May, when their lush new foliage gives the British landscape a heart-stoppingly luminous sheen. But it's no less true in the depths of winter. What beleaguered soul has not drawn comfort from the spectacle of a proud oak, stoically withstanding the onslaught of howling winds while it waits for the renaissance of springtime?

It's hardly surprising that we describe human behaviour so often in arboreal metaphors. We talk about family “trees”, about “putting down roots”, or about “branching out” if we are to avoid becoming “dead wood”. Nor is it surprising that trees play such a significant role in religion. Hindus have their Tree of Eternity - a wonderfully upside-down vision, with its roots in Heaven and its branches invitingly stretching down to Earth like a ladder. Buddhists regard the bodhi (fig tree) as the personification of the Buddha. And the Bible is crammed with significant trees, from the Tree of Knowledge that tempted Adam and Eve to the olive trees at Gethsemane under which Christ prayed before his trial.

Why do we invest trees with such significance? Perhaps because they seem eternal, or at least governed by a mysterious calendar that eludes our understanding. More than 100 trees in Britain are 1,000 years old. The Fortingall Yew at Loch Tay probably predates Stonehenge. And in the inspiring Westonbirt Arboretum in Gloucestershire - which is to trees what the National Gallery is to Old Masters - there's a lime tree that's said to be 6,000 years old.

Even now, equipped with their sophisticated tools, the experts can't say for certain why some trees won't lie down and die. A yew can spend centuries in what appears to be a terminal coma, then suddenly renew itself like a frisky seedling.

Very symbolic. Little wonder that more and more people are asking for a “green” burial when they die. The body is buried in a bluebell wood or suchlike, and a sapling planted on the grave so that one's remains are biologically transmuted into a mighty oak or sycamore that will give shade, shelter and solace to generations as yet unborn.

It's a nice idea. Might opt for it myself. I could even invite Boris to do the planting. Over my dead body!

The writer who bridged the gap

Some books shape your life. When I was 17 and desperate to study for a music degree - despite being coerced into doing A levels in much dustier subjects - I virtually memorised every page of a vast tome called Man and His Music. It did the trick. I managed to bluff my way into the music faculty of one of our older universities. And you could say that I've been bluffing a career as a music critic ever since.

The co-author of that book, Wilfrid Mellers, has died at 94. He was a towering influence. His god was Bach, but he also wrote books about the Beatles and Bob Dylan - for which he was derided on both sides of the fence. People thought, and still think, that musicians and writers about music should “stick to what they know”. But that mentality has led to the appallingly ghettoised musical life that we have today, in which almost no one has the curiosity or confidence to enjoy both Robbie Williams and Richard Wagner, or Coldplay and Chopin. Mellers tried to bridge every gap, especially the gap between music and “real life”. And the fact that I, a humble music critic, have just written 1,000 words about trees, shows that his influence lingers on - in some dinosauric quarters, at least.

An own goal?

What's odder? Learning that tonight's Champions League final involves two teams, Chelsea and Manchester United, who have debts totalling £1.5 billion between them? Or hearing the Man Utd chief executive justifying his debt mountain by saying that “banks wouldn't lend to us if they weren't convinced that we could service our loans”?

Good grief. Has the gentleman been on holiday in Mars for the past year? The world is close to financial meltdown precisely because banks have been lending vast sums to people who can't service their loans. Let's hope that the tactics on the pitch tonight are less insane than the economic thinking off it.