January sun

I am sitting in the sun at 1 o’clock. The sun is just above the trees on the small knoll that sits to the right of the front of the house. The sun is actually amazingly warm despite the time of year. You simply could not sit in the direct midday sun in June, July, August or September. It’s possible in January because the Sun is at an obliquer angle to the northern hemisphere’s surface than in the summer and it’s also passing through a larger chunk of atmosphere than when it is higher in the sky.

I sat here wondering, while watching the newly washed sheets dry, if plants or certain plants need a particular intensity of sunlight and the flow of photons that brings from the sun. So I went and looked it up on the Internet.

I came across this article from MIT which suggests that at the molecular level the plant cells that convert sunlight into oxygen and protons have a ‘quenching mechanism’ when sunlight becomes too intense. When this happens much of the sunlight harvested by the plant is turned into heat as the plant’s cellular mechanisms are threatened by an excess buildup of protons.

The work reported on has tried to isolate this quenching mechanism in the hope that there might be some way of manipulating it to allow plants to utilise more of the sun’s energy for the production of biomass and ultimately food (see extra of homegrown biomass soaking - aka - peasant’s meat- aka chickpea or garbanzo).

So in answer to my question it seems that plants can utilise very different intensities of sunlight from say 1 to 1000 of intensity but when the intensity of the sun becomes too much the plant switches from the production of biomass to the production of waste heat. I don’t really know what this means but it was interesting to think about it while sitting in the brief winter sunshine that rather quickly began to disappear and lose its intensity and warmth behind a veil of cloud moving in from the north.

The photo is looking towards Poppi. I love the almost emerald green of the fields on the valley floor. The phone camera can’t really do them justice. At the time I was rendezvousing with the courier outside the little church at the bottom of the lane.

MIT article here: https://news.mit.edu/2018/mit-energy-initiative-better-understanding-how-plants-use-sunlight-1204