The Tree (52 page)

I am floating these ideas partly through whimsy but mainly to emphasize that although food from trees at present plays only a small part in human affairs (at least if you judge from global statistics), this is largely a historical and economic accident. Grains clearly do have advantages, but they have become as dominant as they have largely through their own momentum. In particular, once the plow was developed (at least five thousand years ago) arable farming became the norm, and everything else became secondary. But if trees had only been taken more seriously, they could have become an enormous food resource—and might be now, if only the coin of history had flipped differently. Indeed, trees have many advantages over grains—they keep the soil in place, they help keep the climate equable—and we should be growing as many as possible. So it is important to change our mind-set, to move away from the idée fixe that says that grains must be central and everything else is marginal. At present, much of Brazil, both rain forest and Cerrado, is being cleared to make way for vast estates of soybeans, which are now Brazil’s biggest agricultural export (and are destined not to feed people but to fatten European cattle—and not because we need the cattle or because the cattle need feeding but because Brazilian soybeans are, for the present, cheap). Yet modern research is showing that the Cerrado could yield far more, and do its society much more good, if its people were encouraged and helped to develop and exploit its native plants. In
Frutas do Cerrado
(2001), EMBRAPA lists fifty-seven native species of fruit, with recipes. The trees among them range from four kinds of araticum (various species of
Annona,
custard apple relatives) through banha-degalinha
(Swartzia langsdorfii)
to pitomba-do-cerrado
(Talisia esculenta)
and puçá
(Mouriri pusa).
But
Frutas do Cerrado
is only a brief brochure: there are scores of other species. Professor Carolyn Proenca of the University of Brasilia lists 120—but stresses that this, too, is just a sample.

Trees provide a great deal of food by indirect routes, too—and again could give us much more. In traditional agrarian economies the leaves, twigs, branches, and seeds—including many that human beings find fairly unpalatable, such as acorns—support significant herds of livestock. In India you commonly see long files of women and girls carrying huge bundles of branches from the forest to feed their cattle. The technology could surely be improved—the work seems mighty hard—but the general idea, that cattle (and sheep and, indeed, goats) can be raised on trees is at least salutary to westerners who think that only grass will do—and is hugely important, since woodland is often preferable to grassland. Pigs and poultry will eat seeds of the kind that humans generally prefer to leave alone, such as acorns. At present, half the world’s cereals (and 90 percent of the soybeans) are used to feed livestock. Since people can live perfectly well on cereals (plus a few extra vitamins), the animals thus become our rivals. Indeed, the United Nations calculates that by 2050, when the human population seems likely to reach around nine billion, livestock will be consuming an amount equivalent to another four billion—increasing the world’s food burden by nearly 50 percent. But if animals are fed on grass—or on bits of trees—then they
add
to our food supply, since we cannot usefully eat grass or trees. Research is in progress to provide better trees for fodder (more nutritious, less toxic), but nothing like the amount that is being done to add another fraction of a percent to the yield of soybeans (which makes more money, though only for a few people).

In various ways production of trees for all purposes—timber, food, resins, whatever—can be combined with production of livestock
or
of conventional food crops in systems known as agroforestry. Agroforestry is in all ways tremendously intriguing. It is ancient in principle—much of the economy of medieval Europe was based on “forestry,” and marauding herds of pigs (in particular) were very much a part of it. But it is also one of the great hopes for the future, and it is now at least beginning to attract the kind of research funding that it deserves.

There is a spectrum of agroforestry. In England, traditionally, farmers often left some trees (notably elms) to grow tall in hedgerows, to provide a useful source of timber in decades to come. Copses in field corners served the same purpose. In northern France, the rows of poplars along the field edges define the character of the entire landscape. They have cash value and in the short term serve as windbreaks—and, odd though it may seem, they form better windbreaks when there are gaps between them than they would if they formed a solid barrier, for solid fences create turbulence. In southern Europe you commonly see broad beans and other crops grown among olive trees. In Andalusia and Portugal cork oaks, valuable in their own right, become even more valuable as black pigs wax fat on their acorns. At the Food Animals Initiative in Oxfordshire, chickens are being raised under young trees—birches, beeches, hazels. Chickens prefer woodland: they are descended from Indian jungle fowl. Allegedly free-range chickens are often reluctant to take to the great outdoors precisely because they feel threatened if there is no shelter—and rightly, because in most places the main threat comes not from foxes on the ground but from above, notably from crows but also from herring gulls (and, to a far lesser extent, from birds of prey). But the aerial invaders prefer a clear run. A cover of trees deters them.

Yet the tropics surely have most to gain from agroforestry. The best coffee and tea is grown under shade. Some spices and medicinal plants grow in woods, including cardamom, an important local industry in Kerala. Leguminous trees are commonly grown for shade: as nitrogen fixers they also help fertilize the crops around them, and their nitrogen-rich leaves make particularly fine fodder. Enormous herds of cattle, pigs, and poultry could be raised on plantations to the benefit both of the trees (which would thereby be manured) and of the animals, which would find food (largely cut for them from the trees) and much-needed shade. The value of shade for livestock can hardly be overestimated. Of the common domestic livestock, all except sheep are descended from forest animals. Of all wild cattle, only the yak and the North American bison take naturally to the great open spaces—and America’s bison is descended, and only in relatively recent years, from the European bison, which is a forest animal and still roams in the forests of Poland. These broad biological observations translate into hard-nosed commerce. Research in Costa Rica has shown that the milk yield of tropical dairy cattle can increase by 30 percent if they are shaded. Contrast this with the parched and desperate herds that traditionally run on the unprotected prairies, pampas, and savannahs. We all like cowboys, driving their dogies across the plains of Texas and Wyoming. But as a way of raising cattle, this is both wasteful and cruel.

Indeed, agroforestry benefits everybody, in all ways. Traditional foresters must typically wait around thirty years before seeing any return on their investment. But if they use the space between the trees to raise other crops (including valuable spice and medicinal crops), they can gain a short-term income too—while all the time the trees grow steadily, to provide a bonanza in the future. Again, I have come across this in Kerala. Again, one wonders why it is not the norm. In most of the world, in most circumstances, agroforestry makes obvious sense. Contrariwise, the present separation of forest and farming that is customary, with the farms more and more monocultural, often makes very little sense at all, except in the short term to a few entrepreneurs. But getting rich quick is not what farming is supposed to be about. Yet there is still a case for growing trees in dedicated plantations—and for harvesting them judiciously from wild forests.

HOW TO GROW TREES

We can grow and manage trees specifically for our own use, and/or we can help them grow just because they have a right to live and are good for other species. Of course, too, by managing the climate and soil, trees are likely to bring us benefit even if we are not specifically growing them just for ourselves.

Trees for our own use can be raised on plantations, and it makes sense to identify the kinds that produce the timber we need and grow most quickly in the land available. This was the thrust of the colonial approach to tropical forestry, in the nineteenth and most of the twentieth centuries. Often the favored trees were exotics, planted in lands not their own; thus the world at large now has many thousands of acres of eucalypts, originally transplanted from Australia. Meanwhile, Australia has estates of Indian sandalwood; South and Central America have acquired teak from India and Burma; huge estates of America’s Monterey pine can be found everywhere; there are plenty of European poplars in India; there’s a great forest of Caribbean pine on the outskirts of Brasilia; Britain’s Forestry Commission planted vast areas of uplands (and sometimes lowlands) with American Sitka spruce after the First World War; and so on.

Such exotic planting has many advantages. Eucalypts judiciously planted in Africa and Asia commonly produce ten times as much timber per year as native species—and this, in theory, should take an enormous burden from the native forests. Commonly, too, species brought from abroad leave their usual pests behind them, so that teak grown in Amazonia, for instance, seems free of the defoliator moths that cause such havoc in India. But there are many drawbacks too. Britons have objected on aesthetic grounds to the military ranks of American Sitka spruce. Exotic trees do provide shelter for local creatures and often supply some food, but in general they are far less hospitable to local wildlife than native species. Sometimes they are positively hostile: conifers on Scottish hillsides increased the acidity of the soil and compromised local flora, and eucalypts on dry soils can rob their neighboring plants of water. Exotic timber trees have often escaped to become weeds—like many a eucalypt and acacia. Parasitic sandalwoods from India grown in Australia have sometimes escaped to attack the local eucalypts, while native sandalwoods in India have sometimes attacked eucalypt plantations. Human beings may choose to manipulate nature this way and that, but the natural battles of ecology continue.

Finally, although exotics often grow supremely well on ideal land, they often fare no better than the natives when planted on poor land; but forest is commonly relegated to poor land, since the best is reserved for agriculture. Then native species would often be preferable because of their general friendliness to local people and wildlife—although they have often in practice been ousted by forestry plantations, effectively as a matter of routine. In Harare, Zimbabwe, Gus Le Breton runs Phytotrade Africa, devoted to the development of native species, not least of the wonderfully versatile local baobab,
Adansonia digitata.
In 2004, at the Forestry Research Institute at Dehra Dun, the then director Dr. Padam Bhojvaid was seeking to reinstate as many as possible of the four hundred or so native Indian species that have been used commercially in the past, many of which have been sidelined through the emphasis on teak (native to India to be sure, but still grown in colonial style on huge monocultural plantations). In truth, there is and always will be a place for plantations of exotics, and the world has good cause to be grateful to the traditional “colonial” foresters who laid the groundwork in science and technique and nowadays tend often to be underappreciated. But it’s a mistake to apply even the best ideas slavishly and under all conditions—as the old-style foresters would certainly have agreed.

Wild forest ideally should surely be kept pristine because pristine forest is, as serious actors say of live theater, what it’s all about. Even so, in a crowded world we are obliged to make use of the natural forest as much as possible without destroying it. Besides, many people worldwide, particularly in Africa, tropical America, and Asia but also in much of Europe, make their living in the forest. Some traditional forest people are true foresters—producers of charcoal, for instance. Others specialize in wild foods or medicines. Nowadays tourism can be a huge source of income—it is the biggest earner by far in Kenya, for example, although it is easier to take tourists around the savannah than through, say, the forests of Southeast Asia. (A ride I took in a cable car at canopy height in the subtropical forest of Yunnan in central China is one of the great memories of my life, the bamboos stretching endlessly below and endlessly above, the air awash with dragonflies, smoky pink and iridescent blue.) But it is important that the cash that tourism generates should benefit local communities, and the habitats themselves, and this is often far from the case.

Above all, wild forest can be and always has been a prime source of timber. Though whereas in the past foresters all too often just took what they wanted (and clear-cut vast areas of North America, for instance, often with gratuitous profligacy), the trend now is to log selectively and sustainably. Tropical forest, with its huge range of species, all of different ages, poses the greatest challenge—but it is one that Brazil’s researchers at EMBRAPA are rising to. Thus the foresters under EMBRAPA’s jurisdiction divide the Amazon forest around Belém into sections. Each section is harvested only at thirty-year intervals—thirty years being a rule of thumb, but a sensible one. They do not simply fell whatever looks biggest and likeliest, or seems roughly to conform to the species they want. They go to great lengths to ensure that they know the particular species of each tree. The reason is as described earlier: what seems to be one kind of tree may in reality be several, and if the logging is indiscriminate the rarer types might be driven to extinction in passing. In any one round of harvesting, the foresters are careful to leave a good representation of each kind of tree—and to preserve especially the most fruitful “mother trees,” to give rise to the next generation.

I spent a day with Brazilian foresters, around Santarém, guided by EMBRAPA’s Ian Thompson; indeed, their work is most impressive. The trees to be felled have all been previously identified, marked, and their position plotted on a computerized map. Because there are so many different species, and only a few of each can be harvested at any one time, the target trees may be widely scattered. Each one has to be located, felled, and then dragged out of the forest to the dispersal point—a task performed by dedicated tractors known as “skidders,” with tracks and grappling hooks. In the bad old days (and still, where the harvesting is less controlled) likely-looking trees were simply felled, and the skidders crashed through the undergrowth to look for them—creating mayhem, and often missing some. Now the skidders follow the most economical route to the trees that have been felled and drag them out decorously, with immense skill, touching no other trees on either side. In the bad old days, logs were often half stripped of bark by the time they were dragged out—and so, it might be inferred, were the trees they had crashed against en route. Now they emerge unblemished.