From The Tree: A Natural History of What Trees Are, How They Live, and Why They Matter by Colin Tudge:
“[Trees] do not dwell only in the present. They remember the past, and they anticipate the future.
“How trees remember, I do not know: I have not been able to find out. But they do. At least, what they do now may depend very much on what happened to them in the past. Thus if you shake a tree, it will subsequently grow thicker and sturdier. They ‘remember’ that they were shaken in the past. Wind is the natural shaker, and plants grown outdoors grow thicker than those in greenhouses, even in the same amount of light….
“Most trees, like most plants of all kinds, are also aware of the passing seasons: what time of year it is and — crucially — what is soon to follow. Deciduous trees lose their leaves as winter approaches (or, in the seasonal tropics, as the dry season approaches) and enter a state of dormancy. This is not a simple shutting down. Dormancy takes weeks of preparation. Before trees shed their leaves they withdraw much of the nutrient that’s within them, including the protein of the chlorophyll, leaving some of the other pigments behind to provide at least some of the glorious autumn colors; and they stop up the vessel ends that service the leaves with cork, to conserve water.
“How do the temperate trees of the north know that winter is approaching? How can they tell, when it is still high summer? There are many clues to season, including temperature and rainfall. But shifts in temperature and rain are capricious; they are not the kind of reliable signal to run your life by….
“The one invariable, at any particular latitude on any particular date, is the length of the day. So at least in high latitudes, where day length varies enormously from season to season, plants in general take this as their principal guide to action — while allowing themselves to be fine-tuned by other cues, including temperature. So temperate trees invariably produce their leaves and/or flowers in the spring, marching to the rigid drum of solar astronomy; but they adjust their exact date of blossoming to the local weather. This phenomenon — judging time of year by length of day — is called ‘photoperiodism.'”
This is the second of two posts with photographs focused on the shapes of desiccated Japanese Maple leaves, that I took in early January. The first post is Winter Shapes: Japanese Maple Leaves (1 of 2).
Thanks for taking a look!