Atmosphere

Frost on the Breath

I showed you a couple days ago how Oregon grape uses fine leaf points to dissipate heat, creating cold points which then attract frost, which creates heat when it freezes, more heat than the leaf loses overall. This is a great winter strategy.

It’s not just Oregon grape who plays this game, though. Look at Choke Cherry. She knows this trick, too.

See those fine points of frost on the bud tips at the top of the tree? Lovely, aren’t they!

You can see them on Siyaʔ, too.

And Mountain Ash.

But not Black Hawthorn. Those melted off as soon as the sun came up.

All that was left by 2 pm were a few drops of melt water at the roots of a few thorns. To go to the other extreme, just 20 metres farther up the hill, there’s a glimpse of how everyone looked at dawn lingers in the colder air.

Siyaʔ

Yes, colder. It doesn’t take much to make a big difference. So, what’s going on here, then?

Siyaʔ

Any frost on the scales of the buds is gone, along with any along the stems themselves. What remains is a little star of frost at the extreme tip of certain buds, specifically the same buds that one can expect to grow first in the spring, with strong deposits of growth hormones laid down last July. In other words, as I showed you three days ago, Siyaʔ, the Food Chief is waking up. The sun has broken open her buds, they are beginning to breathe, ever to slightly, her buds have scent growth hormones to her roots to slowly build up the herds of microbes that will feed her in early April, and some transpiration, just a little bit, is needed, at her growing tips, to allow the Sun to run the system. It’s really the Sun here that’s waking up. The flakes of ice you see on Siyaʔ above an Choke Cherry below…

… are precisely those buds that will grow when the spring comes. We are looking at their frozen breath.

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