I planted some pine cone seeds about 5 months ago, and they are about 8" big now!

So what is so important about bio-diversity?

The countryside - and woodlands - have been modified as you state by man. This has been going on for a few thousand years. Almost every last inch of this country has been modified by us in some way. And now we preserve habits as natural which are in effect artificial. Moorlands and heaths are good examples, both the result of continuous overgrazing and consequent leaching of nutrients from the soil. And as you say oak pasture is certainly not natural.
Woodlands too have been altered to such an extent that it is difficult to decide what a natural wood actually looked like unless you travel to North America, Canada or remote parts of Northern Europe. Left to their own devices many woodlands would end up having a continuous canopy cover with the odd gap here and there as some trees reach the end of their life. That's natural. I've seen woodlands 'managed' or 'improved' for Bio diversity by having been thinned and underplanted. In one case the thinning allowed a fairly dense undergrowth to flourish and destroyed a large area of bluebells. Not very natural that.
The problem is we now decide what is 'natural' -and not nature. Our conservation interventions are not natural.

It's such a good point you make about 'conservation'. Deciding to spent time and money attempting to keep a habitat in aspic can not make sense in the long term. A bit King Canute-like really.

The tree thinning strategy would be ok if grazing could be re-introduced but the example of the resurgent undergrowth is typical of a well-intentioned idea not follwed through. Pointless and destructive as you rightly say.

I am reminded of Toys Hill woodland after devastation of the 1987 storm and how they (the management) selected areas to clear themselves and replant as well as selecting another section to regenerate on its own.

Time passed and Nature did what it does best and that part of the woodland that was designated 'non intervention' faired tons better than the other areas. The Beeb featured this sometime back...

http://news.bbc.co.uk/1/hi/sci/tech/7045944.stm

How beautiful that the most green, cheapest, zero-man hours option worked the best.

Congrats on your pine seedlings, btw !

I planted some pine cone seeds about 5 months ago, and they are about 8" big now!

I've a tree-ID question...

Right now street trees near me in Brighton are shedding what I think are seeds. Papery wrinkled greenish-white oval flakes 1-2cm diameter, with a central rib and a slight tea-coloured

Actually they CAN'T be seeds can they, at this time of year! oops.

What would they be then - flower bracts? I can see the trees covered with dense clusters of these browny papery things. Sadly I can't see the leaf shape clearly and they're too tall to get near a branch. The best I can say is that they're in the hazel/elm/lime family of leaf-shape.

i know that sycamores make a mess at this time of year
but i dont think its them you are on about

That's right. The sycamores have just come into leaf, a couple of weeks later than the ones I'm on about. The sycamore flowers are hanging like discrete bunches of green grapes, whereas the ones I'm interested in have got dense clusters of these papery tea-coloured things along entire sections of the branches (in the middle of the branch, not right to the end); its these that the papery 'seeds' are flying off from.

OK, I have the answer. They're from elm trees. And they ARE seeds. Apparently very few of them will be viable, which is why the elm produces such huge amounts of seed (as I said, piling up in drifts on the pavements).

I don't recognise those leaves as being silver birch. Is it an import or perhaps a foriegn oak species?

Ron.