Sudden 'Fall'!

[Cordaline]

Is it just my imagination or have a lot of trees suddenly dropped the majority of their leaves in the last week!?!
Any suggestions as to why?
Thanks.

[poschiavanus]

The Beech trees have been dropping their leaves in the road for weeks, and there are still lots of new ones to sweep up. However, the timing seems pretty much as usual, with the Copper Beech varieties staying in leaf a bit longer. For these the early leaf fall was greater than usual because of the lack of rain. Wnd and rain has certainly brought a lot more down.

The garden Oak is still pretty much in leaf, although a couple of saplings have lost most leaves now. This tree usually holds leaves until the end of November. Again plenty to sweep up now.

Other trees locally which have certainly lost leaves this past week are Limes, Ash, and a Robinia I noticed this morning. Ash usually are clean of leaves after the first ground frost, but I expect that leaves are fully senescent before that point. So in these cases I think the leaves were ready to fall and its just wind & rain which have brought them down at once.

I'd look for a major change at the first frost.

[Cordaline]

Originally Posted by poschiavanus

The Beech trees have been dropping their leaves in the road for weeks, and there are still lots of new ones to sweep up. However, the timing seems pretty much as usual, with the Copper Beech varieties staying in leaf a bit longer. For these the early leaf fall was greater than usual because of the lack of rain. Wnd and rain has certainly brought a lot more down.

The garden Oak is still pretty much in leaf, although a couple of saplings have lost most leaves now. This tree usually holds leaves until the end of November. Again plenty to sweep up now.

Other trees locally which have certainly lost leaves this past week are Limes, Ash, and a Robinia I noticed this morning. Ash usually are clean of leaves after the first ground frost, but I expect that leaves are fully senescent before that point. So in these cases I think the leaves were ready to fall and its just wind & rain which have brought them down at once.

I'd look for a major change at the first frost.

I figured it had something to do with the weather.
Oak & Silver Birch are still heavy in leaf around here.
There are a few species that are totally bare.
(Unsure of what they are now they're naked.)
Looks to be a while before the frost sets in yet.
Thanks for your info.
Cordaline.

[Dorts]

In the exposed areas here, there are no trees still with leaves except for a few Oaks and Larches. In the more sheltered valleys most species except Ash have still some leaves.
Wind is the major factor in the open areas as to whether trees retain leaves for longer.
Dorts.

[~T~]

Oddly enough in Glasgow our Autumn has been unusually mild so a lot of trees still have their leaves.

[galanthophile]

I noticed the leaves falling from the trees like snow this week.

[Cotham Marble]

Originally Posted by Cordaline

Is it just my imagination or have a lot of trees suddenly dropped the majority of their leaves in the last week!?! Any suggestions as to why?

A number of influences are involved in the shedding process and the importance of these varies between species - temperature, water availability, and day length all play a role, and the mechanical role of wind is also important. In some circumstances leaves will remain on the tree even after the process of dormancy is well established (dormancy being initiated by shortening day length etc) - when this happens (such as in the currently mild and quiet Autumn enjoyed in some parts of the UK) either the mechanical actions of wind, or the mechanical effect of frost on moisture at the leaf axil, when the do eventually occur can cause a sudden loss of leaves from all over the canopy, rather than the more gradual shedding that may be seen when cold and/or wind accompany the progress of dormancy.

CM

[Littlesparrow]

Usually in Cheshire we have had a couple of days of high winds by now and that will get the leaves off, but it hasn't happened this year so different trees seem to be at different stages of bareness.

[wezwez]

We've had trees in various states of fall but, i have noticed one big oak close to where i work which until this week seemed to have resisted. It's now down to about a quarter of canopy

[JoulesH]

I don't know the detailed science but those that do, can use the weather to predict which species will drop leaf shortly. The consultancy I used to work for had the Network Rail contract for vegetation management - not the physical work of managing vegetation but advising on what to do. They regulalry walked the tracks and produced updated maps of what species were adjacent. Amongst other things, they then developed 'leaves on the line' predictions to pinpoint where leaf falls were expected to be heaviest so that NR could go out with the units that spray a special solution on the rails which stops the leaves becoming so slippery.

And yes I have also thought that more leaves have come off this week, our limes are now almost bare and a lot of hedges have dropped their field maple this week too - great pools of golden leaves on the floor beneath them. It has been exceptionally mild here for about 10 days now. Perhaps they are getting rid of the old leaves in a rush before they open the new buds next week in this unseasonal weather!!!!