Colours of Wildlife: The Plight of Plants Part One

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The Plight of Plants Part One

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!"

AcanthaceaeEhretia rigida
Acanthaceae
Ehretia rigida


One of the biggest problems in the world right now, and one of the least recognized, is the destruction of the world's natural vegetation. People have some vague ideas concerning 'deforestation' but lack the big picture to really know and understand what's going on. People seem to have very little 'plant awareness' as such. People don't seem to realize that plants, too, are living, active beings, not just static objects in the landscape. They do things. They simply do things on a scale we're not much aware of. But they feed, they grow, they reproduce, they die. They are impacted by animals and environmental factors, and in turn they themselves influence their environments.


Perhaps the latter is the most important thing about plants. Plants seriously change not just their own neighbourhoods, but the entire world. Without plants, there would be hardly any oxygen in the air. (I'm including here as 'plants' those micro-organisms such as algae and photosynthesizing bacteria, that perform the same function as plants, though technically they are actually different sorts of things.) When the first oxygen started entering the atmosphere, it started a crisis for many living things to which this new gas was toxic, but other things learnt to actually use the oxygen, and this made possible the origin of complex, multicellular life.

Dietes iridioidesBulbine
Dietes iridioides
Bulbides


Plants on land also change the nature of the soil and air. When the Earth was still plant-free, the continents were barren expanses of mud and rock. Rain fell down in torrents and immediately flowed away, rapidly eroding the land; or it sank down into the grit or evaporated. But once plants started growing on land, their roots started to bind the soil, and they absorbed the rainwater and stored it in their tissues, finally releasing it back into the atmosphere through their leaves. The extreme weather became more moderate. Plants released not just water but also particles and chemicals stimulating the formation of clouds. The first forests thus brought their own climate with them as they spread from the coastal and riverine swamps into the continental interiors. Plant activity formed soils. Their roots broke up rocks into smaller fragments, held these together and added their own decomposing tissues to form a humus-rich loam that admitted air and held water, and made it easier for more plants to root and grow.

Mackaya bellaPiper capense
Mackaya bella
Piper capense


Plants thus paved the way for more life on land. The first forests formed about four hundred million years ago. They were colonized by invertebrates at first. Insects were the first flying creatures, and the ancient coal-swamps held dragonfly-like things as big as pigeons. There were millipede-like things over two metres in length, and spiders and scorpions much like those we have today. In the rivers and swamps swam the first freshwater fishes, and soon they were joined by amphibian-like things, the first vertebrates with legs. These crawled out of the water and into the forested interior by about three hundred million years ago. From there, they rapidly diversified into the amphibians, reptiles, mammals and birds that form the backbone of land faunas today.


But again the plants were never static. They evolved and changed just as everything else did. Plants went through several 'phases', sometimes suffering mass extinctions, and experiencing periodic revolutionary innovations. From the start, there were 'inventions' like vascular tissues for transporting water and nutrients, roots for firm anchoring in the ground, and wood for strengthening trunks and branches to enable plants for the first time to grow big and stand tall. There were numerous developments on the front of reproduction: spores and pollen, the 'alternation of generations', seeds, flowers, fruit that enclosed the seeds. The evolution of flowers made possible the evolution of pollinating insects and these in turn drove the diversification of flowering plants. Many plants evolved fruits that were fleshy and tasty, to coax animals to eat them and thus to distribute their seeds, which were passed unharmed through animalian digestive tracts. Plants 'learnt' new and more efficient ways of photosynthesizing and making and storing nutrients. A variety of plants using these and other metabolic tricks became capable of existing and enduring in quite dry environments. Grasses evolved first along moist and sunny riverbanks, but soon proved versatile enough to colonize and conquer much of the world, forming the prairies, savannahs and steppes that hosted the great herds of giant mammals like elephants, rhinos, horses, buffaloes, antelopes and more. Grasses and grasslands even had a major effect on the evolution of humans and their civilizations; our major crops, cereals, are all members of the grass family.

CucurbitImpatiens sylvicola
Cucurbit
Impatiens sylvicola


In all of this, there is massive interaction between all the players. Plants diversified and this drove the diversification of animals, and the diversification of animals, and the changes in how they used and affected plants, in turn drove the diversification of plants. Plants and animals together shaped the entire world. Plants as I've already noted have massive effects on the climate. Animals, especially the big ones, in turn have huge effects on plants and the very nature of the landscapes. Little recognized is the value of some of the smaller animals in creating and modifying landscapes. For instance, digging mammals like prairie dogs, through their vast tunnels, are very important for loosening and aerating soils and enabling many seeds to germinate; termites do the same and more, and their hills become important features of the landscape. Animals with such important roles are called 'ecosystem engineers'.


The miraculous thing is that all of these countless numbers of living things, plants and animals, have been working together for so long to keep the Earth rich in life and also hospitable to life. Over millions of years, there have been cyclical disruptive events, such as changes in the sun, volcanic eruptions, great changes in the arrangements of the continents and the oceans, and strikes by comets and asteroids. These precipitate what are called mass extinction events, when simultaneously a very large number of species all die out at the same time. Often, 'keystone' species that die out, cause cascades of extinctions among species that depend on them or their influence. A mass extinction is followed by some time of ecological chaos and flux as life tries to adjust and establish a 'new normality'. It may take some millions of years before ecosystems around the world are again as rich and stable as they were before the extinction event. But recovery always does take place, and life thrives again.


So when we look at our world as it is right now, we see that it is incredibly rich and diverse in species. As always, plants are the basis of ecosystems on land. There are a few broadly different kinds of vegetations: tropical rainforests, tropical grasslands, often with scattered trees, more temperate grasslands, often treeless, a variety of tropical seasonal forests, temperate forests, shrublands, cold or boreal forests, tundras, and deserts with hot to cold climates. Every kind of vegetation that is natural is the outcome of millions of years of evolution, culminating in the rich mix of species that is best suited to its own part of the world. People can be extremely ignorant of just how diverse natural vegetations can be. Even deserts which look barren at a glance, actually host myriads of plant species that come from ancient lineages. These are capable of surviving on the meagrest of resources, and able to 'hide' themselves well amidst the forbidding landscape. Natural grasslands contain far more than just grass, often concealing substantial underground growth in the form of bulbs, tubers and rootstocks. Forests contain not just trees, but a great many different kinds of trees, as well as shade-adapted herbs and shrubs, climbers, and epiphytes and air plants.


Plants are distributed over the world in various different kinds of communities. Each community has characteristic kinds of plants that support specific kinds of animals. Small differences in landscape, soil type and climate can cause changes in the communities. The northern slope of a mountain, for instance, will host different species of plants and animals than the southern, and even on the same slope, the higher parts will have different species than the lower parts. This leads to the factor called endemism: species are restricted to specific regions. This varies a lot, and some species are extremely widespread, but the majority of living species have fairly restricted ranges, and many are indeed highly localized. In South Africa there are many species restricted to for instance a single hillside, or a small patch of land now contained on a single farm.


Nevertheless, narrow-range species are very well adapted to their own local conditions and need to be respected. Every species in every place has a role to play in the local ecology, all of these together keeping the global ecology going. What's more, the existence of limited-range species can give us great clues to how plants and animals evolve. Each of these species is the outcome of millions of years of adaptation and evolution. The typical lifespan of a species of mammal, bird or flowering plant, is likely to be about one or two million years, and over most of that time, it thrives, and over its entire existence it will be represented by billions or even trillions of individuals. Every ecological community has thousands of species, that all compete, but somehow also support each other. The animals that eat the plants are eventually also necessary for maintaining the conditions that enable a particular kind of vegetation to thrive.


All of the interactions between all sorts of animals and plants have led to levels of diversity that are staggering and still very poorly understood, and most 'regular folks' have no idea about it. When you look over a patch of land, you may have no clue just how botanically diverse it is. At any instant of time, only some of the plant species are conspicuous. In grasslands, for instance, most species are only conspicuous when they flower, and most have short flowering periods, so if you don't catch them at the right time, you don't see them. Some may not even flower during any specific year, waiting until conditions are just right, for instance after a grass fire. There are some that are so tiny that they're completely hidden between the grasses and other plants; to properly see them you have to crouch down. Much of the plant life is contained in the living 'seed bank' in the top layer of the soil. Here, seeds can survive for years, sometimes for decades, until conditions are just right, and then they germinate. So it can happen that during years of exceptionally high rainfall, entire deserts can suddenly be clothed in flowers that seem to have never been there before. But they have been, in the soil seed bank. The wonderful thing is that there is continual change, no year is exactly like any other, but overall, amidst the flux there is stability. Things change, sometimes slowly, sometimes quickly, but life keeps pace.


The immense diversity of plants makes possible the most efficient use of natural resources. And by that I mean something different from how we humans use natural resources. We use resources and use them up, and turn them into garbage and pollution. Nature uses resources by turning them to living tissues, organs, beings, and when one thing is done using them they are used by other things and are cycled through many living bodies until passing back to the soil, the water and the air. It's all part of a cycle that has been going on for millions of years without accumulating any pollution or waste or gunk that clog up the works, and without exhausting any of the resources critical to life. Natural ecology has been efficiently operating since the start of life on this planet four billions or more years ago. Do you think our human way of life, our modern civilisation with the way it 'uses' resources, will be able to make it to a million years? A hundred thousand? Ten thousand? Do you think we'll even last another thousand years, at the rate we're going?


This concludes Part One. Part Two will detail exactly how we have damaged the natural plant life and everything that depends on it on Planet Earth, how we have made an utter mess of the natural ecology, and some ideas what we might do to remedy this, and what might happen if we don't.

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