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Michael Williams continues our series on History and the Environment by considering how long humans have been making ever-growing inroads into forests.
IT IS A COMMON misconception that deforestation is a recent occurrence, gaining momentum in the tropical regions of the world since about 1950. But its history is long, and stretches far back into the corridors of time when humans first occupied the earth and began to use fire deliberately, probably some half-amillion years ago. All that has changed since the mid-twentieth century is that an ancient process has accelerated, and that, compared to previous ages, environments more sensitive and irreversibly damaged have been affected. Possibly as much as nine-tenths of all deforestation occurred before 1950.
Chopping down trees is part of an age-old human quest for shelter, food and warmth. Trees provide wood for construction, shelter and making a multitude of implements. Wood provides the fuel to keep warm, to cook food and make it palatable, and even to smelt metals. The nuts and fruits of the trees are useful for human foods, medicines, and dyes, and the roots, nuts, young shoots and branches (and the flush of young grass after burning) provide food for animals. Cleared forest provides (at least initially) naturally friable and nutrient-rich soils for growing crops. Clearing requires no sophisticated technology. Humans with stone or flint axes need boundless energy to fell trees; in contrast, fire and browsing animals can wreak havoc with little effort. The substitution of metal for stone axes c. 3,500 years ago, and then for saws in the medieval period, eased the backbreaking task of clearing, and accelerated the rate of change, but it did not alter the basic process of destruction and land-use transformation. Power-saws during the last fifty years have made a major impact.
There is much uncertainty about the pace and locale of deforestation during past (and even present) ages. This revolves around the multiple meanings given to three basic questions. What exactly is a forest? What was the extent and density of trees at any past given time? And what constitutes 'deforestation'? Pragmatically one may say that a forest can range from a closed-canopy tree cover to a more open woodland, which affects density. 'Deforestation' is used loosely to mean...