|Forests, Climate, and Hydrology: Regional Impacts (UNU, 1988, 217 pages)|
|2. The living past: Time state of the tropical rain forest|
Origins of Agriculture
But what of man? We are used to the idea that modern man got going outside the forest and, indeed, the grazing typical of animal husbandry as well as the plants and animals typically domesticated are not of the forest. Pre-agricultural man, if we could define him as man, has left little trace, though Corner (1962) has argued that traces of those ancient days are embedded in modern life: a digging stick of the forest became a spade, still with a wooden handle, lianes led to string and rope, palm fibre and bark to textiles, bamboo to piping and, perhaps most outrageously, the range of war-clubs in the Pacific shows the gradation from the wrenched-up sapling with the root-bases as spikes, to the mace, carried in honour in our Parliament.
Of recent forest-people, the Australian aborigines are thought to have removed much of the megafauna of tropical Australia and destroyed much of the Araucaria forest, leading to the advance of the tougher Eucalyptus there. Drainage ditches some 9,000 years old have been claimed for the highlands of New Guinea, a region under intensive clearing for some 5,000 years. Modern shifting cultivation, partially mimicking the gapformation in the natural mosaic of tropical rain forest, has been claimed as the best form of agriculture in terms of soil conservation: it is important to seek out some of the differences between the "natural" and man-made gaps in our consideration of the state of tropical rain forest. In Malaya the Temiar (Carey 1976), one group of the orang ask, the forest peoples thought to have been in the peninsula for some 25,000 years, have no personal land tenure, though certain fruit-trees, notably durians, may belong to particular people and can be inherited. When a new site is chosen for cultivation, the undergrowth is cleared as are some of the trees, though stumps are left as are, for superstitious or practical reasons (often these coincide), certain big trees, like the tualang (Koompassia excelsa, Leguminosae), which has useless timber but harbours bees' nests. Useful fruit-trees are left and are therefore under selection pressure. In the New World, the cultural practices of Maya times are thought to be "fossilized" in the forests of Mexico and Guatemala, for the present-day abundance of mahogany, chicle, and ramon may be explained by their being selected and encouraged to regenerate. When cultivators move on, they leave a tangle of exotic and native plants, including fruit-trees, which they have deliberately planted or encouraged. They may scatter seeds of useful plants, like the peoples of New Guinea, where Artocarpus is sown and pandans are planted in gullies and bogs. Furthermore, the seeds may be dispersed in the faeces of humans. Ridley (1930, 341) records that rambutan seeds are dispersed thus and notes that the allied fruit, mata-kuching, which has thin flesh, is always swallowed by Malays, who consider this to be the only healthy way of eating this type of fruit. The distribution of such fruit-trees may thus represent, at least in part, old cultivation sites, camps, or once-only latrines. Indeed, Lieberman and Lieberman (1980) have argued that during man's early evolution, he had "proto-gardens" of such trees and other plants around occupation sites and that he was initially unaware how edible-fruited plants came to be there, something which might well be called the Eden Syndrome. It is then argued that the evolution of seedgardening involved fleshy fruits and not grasses, legumes, or tubers, for which specialized techniques and/or open country is required. If this is so, then the origins of "agriculture" are much earlier than suspected and, more germane to our discussion now, the association between man and the forest is much longer than is generally suspected.
Much better documented, of course, is the twentieth-century rape of the world's tropical rain forests (Myer 1980). The figures of the rates of telling are so unreal to most people that we are in danger of overexposing the tragedy, with consequently smaller and smaller effect on the comfortable citizens of the developed world. I will add only a few remarks. That which survives in many places is in blocks too small to regenerate and is affected by being surrounded by destroyed vegetation (Janzen 1983): such include the blobs of forest in the middle of Kuala Lumpur and Singapore, for example. Doomed to become impoverished and increasingly secondary in nature, these islands are, in effect, reversing the process by which islands are usually populated in the first place. Elsewhere, the removal of animals by shooting has had the effect of removing the dispersers (Mabberley 1983, 106). Only elephants can swallow the pyrene of an African tree called Panda oleosa: the seed will germinate only after passing through the elephantine gut and being deposited in the droppings. If the elephant goes, then the Panda becomes an anachronism. A notorious and much-publicized example was of the species of Calvaria (Sapotaceae), confined to Mauritius. Only geriatric trees were found in recent years and it was guessed that perhaps it had been dispersed via the alimentary canal of the dodo, extinct since 1681. So turkeys were force-fed and the extruded seeds were said to have germinated and thus brought back the tree from the brink of extinction. Francis Ng at Kepong (1983) has made a list of a number of trees of the Malay Peninsula that will only germinate after the fruit has been opened by monkeys, or the arils removed by animals: with the loss of these animals, trees laden with untouched fruit are an increasingly common sight.