Trees are weird. They harvest sunlight, and eat and poop air.
If you were a tree, parts of you dying would directly make your neighbor grow fatter. I’ve been studying (and teaching) biology for most of my life, but I still find mind-blowing the following sentence from an article from the Journal of Ecology I was reading:
As photosynthesis of C3 plants is not CO2-saturated at [current concentrations], enhanced ‘source activity’ of leaves could stimulate ‘sink activity’ (i.e. growth) of plants.
Let’s take a moment to understand some of the terms in this statement:
C3 plants – These are “normal” plants, meaning they are adapted to moderate amounts of water in the environment. C3 is one of the different types or pathways of photosynthesis, named as such because the first intermediate product is a chemical compound with 3 carbon atoms.
CO2-saturated – Air that has maximum concentration of carbon dioxide. Unlike animals, plants love carbon dioxide because it is the raw material for their food-making.
Source activity – Any activity in a plant when it acts as a source of carbon dioxide, i.e. the gas is released back into the atmosphere, such as when it respires, or sheds body parts, or dies.
Sink activity – Like the article says, it’s an activity in a plant when it takes up carbon dioxide from the atmosphere, like when it uses the food it produces to grow more leaves and stems.
Ok so what does this all mean? It means that trees can stimulate each other’s growth by dying.
Take a minute to let that sink in. Mind-blowing, right?
The article explores the possibility that this ability of plants to grow more with increased CO2 levels can be a way of “buying time” for our society to develop ways to mitigate climate change while more carbon is still being pumped into the atmosphere. Trees are anyway the 5th largest storage of carbon on the planet, after rocks, oceans, soils, and the atmosphere. They’ll save the human race from extinction.
Sadly though, it seems that the results of that scientific study indicates that we can count little on such a carbon dioxide-induced growth stimulation to buy us the time we need. This is because growth of mature trees in all the climatic zones they studied, from the Alps to the tropics, seem to be affected insignificantly by increased carbon supply.
We should stop looking for some deus ex machina to come save our planet. Among all the major carbon storage compartments on earth, trees are the ones we can do something about, at least in the sense that we can actively increase their storage of carbon. Our society has the responsibility to exert all efforts to reduce our carbon emission by not wasting energy, reducing fossil fuel burning, adopting a green lifestyle (eat less meat!), and of course, planting more trees and stopping deforestation.
Go and look out your window right now, and say a silent thank you to that humble tree outside, saving your a** from climate change by being weird. Better yet, go and plant a tree!