We frequently see diaries and articles about global climate change. Discussion rages about the cause and the extent of the change, and, occasionally, as to which direction it will go. Most of us understand that scientists have reported a great deal of evidence to support the fact that our planet is currently warming, and that these changes appear to be encouraged by man-made outputs.
I strongly believe we can and should do everything in human power to reverse course and stop or slow human outputs that influence the climate. We voted for change this past fall, but this is a change some of us hoped votes we cast would help stop. Regardless, change is happening around us, and we must prepare for it.
When reading about climate change unsettles me, I sometimes need a little reassurance. Today, I turned to an old childhood friend for help.
Today, I turned to Ginkgo biloba. The ginkgo tree is known also by the common name of maidenhair tree. Its bifurcated leaf strongly resembles the leaflets of another ancient plant, the maidenhair fern. You can read all about them and see pictures and videos of them at the ginkgo pages.
I find ginkgo trees reassuring when I read about change in our biosphere. They are durable survivors, in some ways an example of what we need to be, in others a fantastic metaphor.
They have a fascinating story. Ginkgo trees are well represented in the fossil record, and were widespread among the flora of what are now North America and Eurasia over 200 million years ago. This group of plants shared air with dinosaurs. In the early ages of modern botany, it was presumed they had gone extinct. Not so.
Somewhere in China, pockets of wild ginkgo trees must have survived. The "nuts" of the ginkgo tree (which grows as either male or female -- no tree naturally has both sexes) are part of eastern cuisine, and somewhere in the early shadows of east Asian civilization, the trees were cultivated. They were found by a western botanist in a temple garden in Japan in the late 17th century. There are populations of the tree that may be wild, but that is in dispute at this point, by my understanding -- it may be that all extant populations of the tree were, at some point, human-planted and tended by people.
Treasured as a living fossil, ginkgo trees have become a popular horticultural subject worldwide. No wonder -- not only are they beautiful and of varied, exotic form, but they are incredibly tolerant of abuse. They survive heat and urban pollution effortlessly, and don't mind being pruned to fit tight spaces. Not only that, but they are long-lived. Individuals of this species may live for millenia.
The species is as unique as it is beautiful. No other living plant has a leaf vein structure like those of Ginkgo biloba -- the veins are parallel, yet occasionally and seemingly randomly branch. It's called dichotomous veining, and only the ginkgo tree does it. Another interesting habit people notice is the tree's stunning autumnal performance. First, all the leaves turn a stunning golden yellow. Then, as if on cue, the tree drops all of its leaves rapidly, often within a day or even a few hours. Observers have noticed that sometimes many trees within an area shed their leaves simultaneously. I don't believe we've ever discovered the exact cue on which they drop their fabulous foliage.
And the leaf! It, too, is unique -- once you're shown a ginkgo leaf, you'll always recognize them. Their unusual shape makes them a popular subject of art and element of design.
To me, their tale of hundreds of millions of years' survival tells me that if they can do it, so can we. Homo sapiens is a much younger species than Ginkgo biloba, and I suspect significantly more fragile. We have made a habit of changing the environment to suit us, and the environment may yet outwit us and remind us that nature still holds the vast majority of the cards and can wipe us out if need be. To reproduce the ginkgo tree's feat of perseverance, people will have to learn to be tolerant -- of one another, of environmental change, of environmental extremes -- and to be able to adjust and survive in the environment as it is.
At the same time, Ginkgo appears to have survived because people found value in this species, sheltered it, and propagated it. This living fossil is again widespread because human beings took the last scion of a once-grand family of plants under our collective wing and nurtured it wherever we went, often in places we held sacred. We can do that for many other species, and we do. We can do it for the planet as a whole. Homo sapiens has been around in our modern form perhaps a couple hundred thousand years. We owe Ginkgo biloba a few hundred million more.