In many parts of the world the crocodile is disappearing. We shall miss this highly unsympathetic animal because he performs a very valuable function, as is now being discovered: crocodiles kill off the enemies of fish as well as the weak and diseased in the fish population. Where they have disappeared the fishing is much worse.
The great wild species of Africa survive at all solely because there are national parks in various parts of Africa where these animals are carefully protected. Presumably they will continue to survive, for the benefit of science and for the delight of people who wish to go outside the all too human world and see what the rest of the creation looks like.
Let us now consider the plant world. We will begin with the forests. I have already talked about the cedars of Lebanon, an immense forest of magnificent trees which have virtually disappeared, leaving the mountains to be eroded. In many places all the topsoil has been washed away and nothing remains except the naked rock; such places, it is quite clear, can never be reforested, and this same situation occurs again and again in every part of the world.
Man has been deliberately destroying forests since the hunting period: to clear forests—to increase visibility—the hunting tribes tended to burn off the underbrush, permitting the game to be hunted much more easily than it could be in a very dense forest. And, since agriculture began, probably about 8000 b.c., men have been cutting (and burning) forests in order to create new places where they could plant food crops. The whole process was greatly speeded up after the beginning of the iron age, when it became possible, with the use of iron ploughshares, to break soils much too heavy for the wooden ones which had been used in the past. Another invention important to the greater spread of agriculture came towards the eighth century, when what appears to be an extraordinarily simple device, namely the horse collar, permitted horses to pull a much greater weight and to put much more strength into their pulling than they had been able to do with the previous forms of harness. Such technological advances, plus a slow but steady increase of population, have naturally led to the clearing of enormous forests.
Equally important in more recent times, especially in the destruction of forests which surround urban centres, has been the use of timber as a fuel. If you read Diderot’s Encyclopaedia, you will find a very, very interesting account of the provisioning of Paris with wood for space heating. All the forests around Paris had been largely exhausted and the wood came in from hundreds of miles away, being floated on great rafts down the Seine and its tributaries. The rafts were then moored off the quays of Paris and the wood distributed. Diderot, one of the few intellectuals of the eighteenth century who was deeply interested in the technological progress of his time, stated that this could not go on and that the only hope was to use coal for space heating; in fact, at about this time coal did begin to be used on a considerable scale, which helped to save the forests from total destruction.
Besides space heating, wood was used in industry. All ores were smelted with charcoal until steel was made with coke for the first time at the beginning of the eighteenth century, so that there was a prodigious destruction of forests wherever there was a metallurgical industry. The same happened wherever there was a glass industry. Although glass was a very early invention—it goes back to about 3000 b.c.—it was very expensive and difficult to make until the art of blowing glass was perfected in the first century a.d. This invention very rapidly led to the formation of glass industries all around the Mediterranean and as far north as Cologne and England, with the consequence of an enormous massacre of the forests.
Another very important reason for the destruction of forests was the building of houses and, even more significant, of ships. It is interesting to find how early the timbers suitable for building ships were exhausted in Western Europe. The French navy couldn’t find suitable timber in its own territory from about the end of the seventeenth century and had to be supplied largely by timber coming from as far afield as Albania. The Spaniards, at the time of their great naval expansion during the sixteenth century, were depending not upon wood from Spain, but upon wood coming from the Baltic.
You will find a reference in Pepys’ Diary saying, ‘God knows where our oak is to come from.’ And in fact the oak was running out. By the eighteenth century, the period of Britain’s naval supremacy, the oak for its ships was coming predominantly from the New World—from New England and the Eastern seaboard of this country. As for the rest, it was teak from the Indian Empire. Fortunately, perhaps, the Battle of Hampton Roads in 1862 proved that the iron ship was definitely superior to the wooden, and consequently shipbuilding ceased to be a reason for massacring forests of slow-growing trees.
The area where one sees the deforestation most clearly is in the Old World, most visibly in the ancient civilized world around the Mediterranean. You see it also terribly clearly in the Northwest here and around the Great Lakes. There are, of course, great forests remaining in the United States, but the annual cutting of timber exceeds annual growth by about 50 per cent. It is quite obvious that you can’t go on with this kind of thing for very long and hope to have many forests.
The forests in Europe used to come right down from the northern part to the Mediterranean coast. Today there are very few areas on the Mediterranean coast where you can still see traces of the ancient forests. In the south of France, east of Hyères, there is about a hundred square miles of forest called the Forêt des Morts; it is all that remains of the great primeval forest, which had already largely disappeared even in classical times, and which just vanished during the Middle Ages, largely because of the glass and soap industries of Marseilles and the shipbuilding industry of Toulon and Marseilles.
For those who are interested in landscape painting, it is a curious thing to realize that what we consider the typical landscape of Provence, such as we see in the paintings of Cézanne, is a relatively modern landscape. It represents hills which have now been weathered down, practically to their bare bones. Probably many of them are hopeless cases and can never be reforested. They are extremely picturesque, but we must remember that they are thoroughly a product of degeneration and destruction. The same thing is true of other parts of the Mediterranean. If you go to Tunisia and drive inland from Sousse, you will see a gigantic Roman amphitheatre, El Djem, which is second in size only to the Coliseum, standing in the middle of the desert.
El Jem was situated in a province which in Roman times was called Frugifera, the fruit-bearing province. Today it is almost completely deserted, with a few Arab huts scattered about at the foot of the great buildings. This same picture occurs again and again. Homer speaks about the tall oaks and pines of Sicily. Now you can cross Sicily from one side to the other and hardly see a single tree. There are a few places where attempts at reforestation have been made, but this once extremely well-forested, well-wooded country is now almost completely naked. The same is true of Greece, of Palestine and Syria, of Spain, and of Southern Italy.
Now we have to pass to another area of destruction at least as important as the destruction of forests—and resulting in some measure from it: the destruction of the soil.
The soil is a living organism. It owes its fertility to the existence within itself of great numbers of ecological communities of microscopic and macroscopic organisms of every kind. The topsoil, however, which contains almost all the soil’s fertility, is not deep. The 2.8 billion people who are now inhabitants of the planet depend upon a layer of soil rarely more than about ten inches thick—and it takes three hundred to one thousand years to create an inch of it, so one sees the extreme danger of any process causing soil destruction.
Soil erosion, of course, happens all the time; it is one of the regular processes of geological change. But there is an immense difference between the slow erosion of nature left to itself and the rapid and destructive erosion which takes place when man wantonly strips the land of its vegetable cover, cuts down the forests, tears up the grass, or uses bad agricultural methods which leave the land vulnerable to the wind and the rain. Unfortunately, as we have seen, man has been committing such crimes against nature for a very long time.
One of the best descriptions of erosion was written, curiously enough, by Plato in his dialogue, the Critias, where he speaks of his own native country of Attica. It is worth reading because it is remarkable how accurate the description is. He says:
In comparison of what then was, there are remaining only the bones of the wasted body, as they may be called, as in the case of small islands, all the richer and softer parts of the soil having fallen away, and the mere skeleton of the land being left. But in the primitive
