Plantwatch: how in winter, bark can act like leaves for trees

[Judi Lynn]

This article is more than 1 month old
For some trees, photosynthesis can take place in the bark, letting the tree supplement its food reserves

Paul Simons
Wed 15 Dec 2021 01.00 EST



The broadleaf trees are now standing bare without their leaves and they look fairly lifeless, but appearances can be surprisingly deceptive. The aspen has striking white bark but that of the younger trees tends to have a greenish tinge thanks to chloroplasts buried in the inner layer. When sunlight penetrates the thin outer bark it can be enough for photosynthesis, aided by tiny pores in the bark that let carbon dioxide and oxygen gases pass in and out. And so, even in winter, the tree can supplement its food reserves.

Sunlight can also penetrate the thin outer bark of beech or silver birch, or the bark of tender saplings of other trees where there is enough chlorophyll for photosynthesis. Trees such as silver birch have bark that also peels away and may let in more light, but even in the thicker bark of other trees light can still penetrate through cracks, whether the bark is craggy or smooth. And the leaf buds and twigs of many trees can also make food by photosynthesis, even if only for a week or two before the buds open, a welcome boost just as spring gets going.

https://www.theguardian.com/science/2021/dec/15/plantwatch-how-in-winter-bark-can-act-like-leaves-for-trees

[niyad]

1. Fascinating. Thank you so much for sharing.

[Lonestarblue]

2. Nature is amazing when we leave it alone.

But we humans just can’t resist trying to pollute it and kill it for our own purposes.

[bucolic_frolic]

3. Inquiring minds want to know

So Mr. Tree, do you find your photosynthetic romps with the sun more pleasurable in the heat with leaves, or in the cold deep into the bark?

[electric_blue68]

4. Fascinatng!