The Plight of Plants Part Two
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
My previous article detailed the evolution of plants on land and how they sustain the lives of everything else. This article will be about how we humans have been messing all of that up.
Initially, humans, or their almost-human precursors, were just one more species amongst all the animal species on Earth. But our ancestors were very adaptable. They scrounged for food wherever they could find it, eating plants, insects, the eggs of birds, fish, shellfish, the flesh of animals, sometimes ones they could kill themselves, sometimes banding together to take the prey of large carnivores like lions. From the start, humanity has been an 'everything-eater'. We ate our way through the global ecology. We ate ourselves into an inflated sense of our own importance. We developed weapons, learnt to use fire. With fire we first started changing the world around us. Forests we burnt down, because that drove out animals for us to kill. The grasslands that replaced the forests were also easier places to hunt in. Early hunters wreaked absolute havoc, driving the extinction of so many large mammal species: all the mammoths, all the giant ground sloths, all the giant armadillos, all the North American horses and camels, the giant birds of Madagascar and New Zealand… I could go on and on but this is not that article. But our 'superiority' to everything else is clear … in the sense that beweaponed, co-operating human beings were able to destroy or kill any other living thing they encountered. Oh, we got back some of our own medicine, since humans from the very first waged war on other humans. Humans quite often turned to humans belonging to other groups as a source of food also. It is likely that Homo sapiens drove the several other species of humans that, initially, co-existed with it, into extinction.
Many human cultures eventually evolved beyond mere hunting, into agriculture. That was even worse. Now vast swathes of land were ploughed up, especially grasslands. As I've said in my previous article, wild grasslands are actually very diverse in plant and animal species. Even if some of those grasslands were already the products of human changes, having replaced some of the forests that had been burnt down not so long ago, they still hosted thousands of species of plants that supported thousands of species of animals. But ploughed up, those lands now hosted just a handful of species: wheat, barley, sorghum, rice, maize, potatoes, or whatever else the local farmers wanted in their fields. Every other plant was removed as being a 'weed' and any animal whatsoever, from an insect to an elephant, was driven away or otherwise persecuted for wanting to eat this plentiful food that rightfully belonged to the farmer or the farming community. Humanity got the idea of everything on Earth, every part of Earth, being its actual or potential property.
Agriculture further drove humanity's own evolution. Prosperity increased, for some people there suddenly was lots of leisure time, and they got to think up all sorts of new things. Weapons were improved, for hunting more animals and also for destroying human enemies. Agricultural communities destroyed and replaced nomadic herding and hunter-gatherer societies. Farm implements were perfected, we domesticated animals, some of which we pressed into helping us destroy the wild world further. With new and improved axes and saws, we cut down entire forests. Our farms became bigger and bigger. Human settlements expanded, we built cities.
Where any modern city or town now stands, there once was wild land. What happened to the original animal and plant inhabitants of the wild land on which the city now stands? They've simply been destroyed. I see it in my own town. Polokwane is a fairly new city. When we came to this town, in 1980, we were on its very outskirts. Our house was built on what was up till then wild savannah grassland. There were trees like common hook thorn, spike thorn, guarri, puzzle bush, karee, caterpillar pod, wild fig, wild olive, wild medlar. There were dozens of grass species. Amidst the grass there were wonderful small plants: Jatropha, Cyphostemma, Raphionacme, Gladiolus, Chascanum, Rotheca, Adenia, Euphorbia, Dipcadi, Ornithogalum, Albuca, Boophone, Aptosimum, Elephantorrhiza … those are the scientific names of some of the genera; many of these don't even have well-known common names since the common people hardly ever took notice of them. Yet, they are all lovely, wonderful and unique plants – my photos here give you just a bare inkling of the botanic wonders of this region. But the new house-owners didn't give a fig; everything was cleared away. Even my father, otherwise a very considerate man, and respectful of nature, wasn't aware anything wrong was being done. He saved a few of the wild trees that stood on our plot of land, but the small plants were lost entirely. They were replaced by garden plants: in our garden, they included hydrangeas, jasmine, delicious monster, all species not only not originally from our area, but not even native to South Africa. We wised up later and replaced almost all our garden plants with indigenous species, but they are STILL not totally representative of the original wild plants. Many of those original wild plants are very hard to grow in an actual garden – I'm still frantically trying to figure out how to do that. They need for instance fires at certain intervals of time, which is a hard sort of regimen to implement in a garden, and they need the activity of large mammals like zebras and rhinos, again not commonly found in gardens even in South Africa. So even though my garden has some native species, it is still not as biologically rich and ecologically complex as actual wild land would be, and had been before.
And most other gardeners are far, far less conscientious than I am. They completely replace the wild plants with showy exotics, plants not native to South Africa. And those exotics, while being showy, do hardly a thing to sustain a vibrant ecology. The garden owners heavily use pesticides to kill any living thing that comes to feed on 'their' garden plants, and these plants, not being native, to the area, need extra care, such as regular watering and fertilization, whereas the wild land needs nothing of that, while sustaining far more diversity. So just maintaining these 'green deserts' also eats up a lot of resources.
And more and more houses are built, more and more plots of land are cleared to make way for 'green desert-style' gardens, more and more roads criss-cross the land, more and more fences constrain the movements of animals, more wild land is ploughed to become fields that can grow food or other crops humans find useful, forests are still cut down to make way for cattle pastures, soy bean fields, or oil palm plantations, wetlands are drained, coastline-protecting mangrove forests are cleared for fish farms, land is cleared to make way for mines, factories, power plants, shopping centres, schools, hospitals, things we humans sorely need, but our needs just keep growing and growing while the planet that must provide these needs does not.
And what we don't destroy, we pollute. Toxic gases go into the air, toxic wastes go into the water and soil. Plastic refuse now clothe the shrubs and trees of South Africa like flowers. A little-known thing is pollution with living things – invasive species of animals and plants. These are species that are brought into places they didn't occur in before, which have ideal conditions for them to thrive in, and no predators or competitors. Not many people are aware of the incredible damage caused by these living agents of destruction. In their own, native ecosystems, they were valuable and in interaction with everything else, in balance; outside their native systems they are totally out of control. Such species include the cats, rats, pigs, mongooses, monkeys, and in one noteworthy case, a tree snake, that were brought by human sailors to islands that previously had no such creatures on them, no major land predators. These islands always had birds and other critters that completely lost the instinct of fleeing from predators, simply because there never were predators they needed to flee from. Thus they were like an all-you-can-eat buffet to the new predators. Incredibly, even house mice have turned predator and now, for instance on Marion Island, are eating the chicks of albatrosses and other species of seabirds, who have no instinct whatsoever for dealing with these new, tiny little predators that come sit on them and slowly eat them alive. Hundreds if not over a thousand species of island birds so far have been lost to these introduced predators. On continents, introduced, invasive animals included lots of large, predatory fish species introduced into lakes and rivers for the sake of providing 'sport' to fishermen, leading to the extinction of local fish species. And remember, it is WE who are responsible; without us, those predators would all have remained in their own native environments.
Even less awareness exists for the similar damage-causing potential of plants. While, as I've said, many exotic plants need extra care to survive in the gardens where they're planted by humans, some find themselves in climates just perfect for their needs, and again, an absence of predators. In the case of the plants, these predators are mainly insects. Insects are typically narrowly-adapted to specific plant species, so any 'new' kind of plant in a region might very well find itself with nothing that's adapted to eat it. Such species thrive. So … these species become invasive. They reproduce and spread their seeds beyond the borders of the gardens where they're planted, and establish themselves in the patches of wild land that remain. Being immune to predation, they out-compete the native species, and soon clothe huge swathes of land, crowding out what's left of the natural native flora. Several of these invasives are aquatic plants, spreading to cover the surface of lakes and rivers, changing the local ecology to make it no longer suited to the native fishes and other aquatic critters.
(Something I can't go into in this article but that is related, is the spread of diseases among plants and animals as a result of humans – but that, too, is a relevant factor. I hope to do an article about that soon.)
Even plants indigenous to a region can turn invasive as a result of human disturbances. In nature, many such plants are pioneers. Disturbances do happen in nature, as a result of for instance fires, floods, landslides, tree-falls, or the large-scale activity of giant mammals. This disturbed land is rapidly colonized by fast-growing pioneer plants; but they soon die and make way for the longer lasting more permanent plants. So they have their natural place and role, rapidly returning disturbed land to balance and stability. But now, much of the land around human habitations is permanently disturbed by actions both of people and of our domestic animals, so that large portions of land are now invaded by these pioneer species such as (in South Africa) sickle bushes, 'boetebossies' ('fine bushes' since farmers could even be fined for not getting rid of them), fluffy-seed bushes, 'ouhout' ('oldwood', a shrubby kind of tree) and others. Where goats, cattle and donkeys graze too much and fire happens too infrequently, trees and shrubs take over from grassland, which we call 'bush encroachment'. This leads to permanent change in the plant composition of the area. And because wild lands are now divided into separated patches by all our other developments, any original grassland plants that can't survive along with the newly-established trees and shrubs, cannot 'escape' into an adjoining grassland area, since such areas are often too far away, separated by roads, farms, settlements, mines, whatever … so the original grassland plants simply die. They become locally extinct, and if they were particularly restricted in their occurrence, also globally extinct.
We have much changed the factors that influenced, maintained and sustained the plant growth over the entire Earth. We have destroyed the great grazing and browsing animals, the mammoths, the giant sloths, the rhinos, the elephants … only the last two of which still exist, but now hanging on precariously in a few comparatively tiny protected spots. We eliminate as far as we can the digging animals like prairie dogs, or the termites. These creatures once shaped entire landscapes. The plants of those landscapes adapted to them, and without them, many of them cannot grow or reproduce effectively. So those plants may be gradually going extinct, and with their extinction, in turn, will come the extinction of many of the animals that depend on them. This is how 'cascades of extinction' happen, once major role-players in the ecosystem are eliminated.
So … with things looking as they are right now … even if we do not destroy much more additional wild land (which is unlikely since all signs indicate that in the foreseeable future we're even going to be accelerating the pace of destruction), we might still be facing an extinction of 50% or more of all plant species. How will that affect us? We might ask, how will that affect the global ecology? We know very little about ecology, still. It is possible that the global ecology has much redundancy in it – that there are enough other living creatures to take up the roles of the species that are eliminated, that the ecology as a whole will not suffer much. But then, with the way we've disturbed the global ecology, it might very well turn out that we've rendered ecosystems incapable of responding to this disruption and impoverishment. Because of all the barriers we've created to the natural spread of plants and animals, when a species in one region goes extinct it might very well be impossible for something else to come in and take its place. Consequently … the global ecology might very well be what we might call crippled.
And at the very time that we're potentially crippling this ecology, we still don't have the faintest clue how it actually works. How can we study ecology except by studying what is around us? And if what is around us, is no longer a pristine ecology, but one that has been massively changed, then we don't and can't have any idea how it worked originally. We need a pristine planet to study in order to understand how the living systems of a pristine planet work together. We can go now to the wildest places that remain, and study ecology there, and indeed we can learn much … but can we learn how the planet as a whole works? We can learn how a crippled planet is still hobbling along, but we have no idea what that planet was once capable of or might be capable of again, if we only let it.
We've destroyed so many wild populations, so many species even. And plants are every bit as wonderful as animals; the extinction of a plant is as final as the extinction of an animal, as much as a loss as the extinction of an animal, and to boot, might very well cause the extinction of one or more species of animal that depended on it. We don't even know what all the things are that we've destroyed. We have no idea what we might have learnt from them. They could have taught us about how ecology works, how living systems hang together and drive each others' adaptations and evolution. Every species that disappears, is like a missing piece of the puzzle of making sense of Life on Earth … and we're losing more and more pieces. And we have no box cover. We might never know what the picture once looked like.
The wonderful thing is, though, that evolution continues. We might destroy 90% of all living species … such a thing happened before, in the extinction at the end of the Permian period. The few species that survived this extinction into the Triassic, re-colonized the Earth, re-diversified, and within some millions of years, were as diverse again as their Permian precursors had been. This will be so with us as well. The survivors of the mass extinction we are causing, will re-colonize the Earth and re-diversify. But that will take millions of years. And what about us? Well … if you ponder it, if we do something that's bad enough to destroy 90% of nature … it is very likely that we, too, will be among the species that go extinct. If that doesn't happen, if we survive a mass extinction of our own making, without having learnt the lesson of not destroying the biosphere, we will keep destroying of course and cause another mass extinction … and we might go on like that until at last we do manage to destroy ourselves as well, finally leaving the scene clear for Nature to recover. Which will take millions of years, and without us being there to appreciate it. Only if at some point we learn the lesson of not destroying the biosphere of the Earth – that is, the entire system of planetary life including us humans – may we live to see and appreciate a global ecological recovery for ourselves. The choice of if, how, and when that will happen, is up to us.