Deforesting the Earth: from Prehistory to Global Crisis


Deforesting the Earth: from Prehistory to Global Crisis. Williams, M. 2003. University of Chicago Press, Chicago, IL. 689 pp. $70.00 (hardcover). ISBN 0–226–899268.

The title of this impressive book succinctly indicates its very ambitious scope, describing how most of the earth's forests have been cleared, for many regions not once but repeatedly, from the time people came to new areas to the present. Its subject is summarized in the preface as being “… how, why, and when humans eliminated trees and changed forests, and so shaped the economies, societies, and landscapes that lie around us” (p. xxi). Deforesting the Earth is a seamless blend of historical geography and environmental history. But as Williams also says in this section, this book is not a history of forests, forestry, industrial and domestic fuel use or of conservation and environmental concern. The common theme throughout is that humans have cleared nearly all forests in all countries for a variety of good and services, including fuel, agriculture, building material, and money. No time period or region of the world receives inadequate attention. This book also represents a fine prospective about the beginnings of many conservation-related topics, including soil science, forest science (including forest health), ecology, conservation, and animal husbandry, and the underlying development of peoples' attitudes toward trees and nature.

The subject of global deforestation during the past 10,000 years receives the space it deserves. Nearly 700 pages of small print summarize a tremendous number of references examined: 76 pages of notes to supplement material in each chapter and over 1600 sources included in the bibliography. So many statements seem so significant that it was difficult to refrain from underlining the majority of this book. The nearly 50 plates, 100 figures, and 46 tables add much substance throughout.

Fourteen chapters comprise three main parts. Part 1, “Clearing in the Deep Past,” documents the effects of agriculture, domestication, and use and suppression of fire from the time forests returned after retreat of the glaciers until before the industrial age. Chapters in this part briefly summarize the return of the temperate and tropical forests following glaciation and detail the many ways early humans used or took advantage of fire, the history of agriculture, and land use in classical (Mediterranean) and medieval (western and central) Europe and Asia.

Part II, “Reaching Out: Europe and the Wider World,” covers key aspects of the development of a world society as they affected global deforestation in six chapters arranged primarily by geography and two main time periods, 1500–1750 and 1750–1920. The book organizes changes to forests prior to 1750 primarily by what happened in Europe versus “the wider world.” Between 1750 and 1900, deforestation in the temperate versus tropical world is distinguished. It is especially during this period of very intensive and extensive deforestation that conservation, forest management, and environmental ethics began to develop, including George Perkins Marsh's Man and Nature: Or, Physical Geography As Modified by Human Action, published in 1864.

The three chapters of Part III, “The Global Forest,” examine global deforestation during 1900–1995, including serious concerns, some realized and some not, about world wood shortages. Foreboding about tropical deforestation was warranted, however, because about 318 million ha2 of tropical forests were cleared between 1950 and 1980, a result of ever-expanding populations and further advances in technology (e.g., gasoline-powered motors). Most of Part III examines tropical deforestation. Forest acreage actually increased during this period in the United States and Europe because agricultural land was left to natural succession or planted to trees.

The epilogue, “Backward and Forward Glances,” is a too-brief section of introspection and modest predictions, toward the end stating that “Deforestation is no longer a purely economic issue … as it is also fast becoming a matter of humanitarian concerns mixed with long-term environmental ethics” (p. 500). The author states that world population is expected to stabilize at between 9 and 10 billion by 2100, with most of the three to four billion extra people living in and depending on tropical forests. And although the population of the developed world is expected to remain about the same, real incomes are expected to continue to rise, increasing demands on wood and pulp among other world resources. One source cited forecasts of a 25% increase in demand for global wood products between 1996 and 2010, only a 15-year span. Other possible threats, such as acid deposition and climate change, do not appear to be fading.

I found so much of this book enlightening that emphasizing only a few examples of important statements seems wholly inadequate. And while many probably have read such statements in other sources, the amount of documentation that underlies these provocative statements and how they are woven into a strong, coherent story make them especially effective.

For example, for the past few decades, many basic ecology courses no longer try to persuade students to believe in the “balance of nature.” But the author's longer-term perspective on this concept is more persuasive: “…the terms presettlement and postsettlement should be consigned to the intellectual trash can. Concepts of ‘natural’ and ‘equilibrium’ have probably not existed since the end of the Ice Age” (p. 28).

The book describes “one of the greatest episodes of global deforestation ever enacted” (p.301), the clearing of forests in the United States from 1850 to 1899 while the population of the United States grew from 23.2 to 74.8 million. About 300 million acres (121.4 million ha) of forest were eliminated. Trees continued to be used for fuel, construction, and fencing, but railroad construction used about 20–25% of this timber. By 1900 deforestation eliminated about half of the original forest cover of the United States. In 1906 U.S. lumber production reached 108.5 million m3, two-thirds of the world's output. Per capita consumption was 1.24 m3, an amount never matched at any other time or in any other country in the world.

Regarding tropical deforestation from 1750 to 1920, Williams says that “…long before the supposed Eden was spoiled by the grasping, exploitative European invaders, shifting cultivators and peasant agriculturalists were chopping, cropping, burning, and grazing their forests, changing them to cropland and grassland” (p. 336). Furthermore, “…the transformation of 56 million ha of forest to grassland in the tropical world between 1750 and 1900 is one of the striking features of global land-cover change” (p. 342).

There is a brief section on concerns about the effects of deforestation on biodiversity, especially in the tropics, and the evolution of this term over the past few decades. But, as sobering as this book is overall, it could be much worse if it included specific information about the effects of deforestation on regional biodiversity. For example, although Williams discusses the occurrence of forest regeneration in many regions at various points throughout history (e.g., the caption to Plate 3.1, referring to the tropical forests around the Mayan temples at Tikal: “The ability of the forest to regenerate when human interference ceases is awesome”[p. 61]), the author does not discuss how the rest of the forest community has been affected by these clearings followed by regeneration. Much evidence is accumulating that although trees can return fairly quickly to sites cleared for agriculture and eventually abandoned, the forest understory and associated animals and many ecosystem processes are much slower to recover. And with surrounding, contrasting land-use and threat from invasive species, perhaps many of these lands will never “recover.” Of course, those who regularly read Conservation Biology are already well informed about the many ways in which deforestation adversely and often permanently affects biological, ecological, and sociological systems. I point this out not to criticize the scope of this book, just to indicate—to anyone who finds a positive side to the story it tells—that there still is much about which to be greatly concerned.

From the excerpts I include here, one should not get the impression that this book is written by some cranky author. It is very well balanced and is clearly written so that its messages cannot be misconstrued. Williams clearly and dispassionately presents his story, which further enhances its credibility. Yet the subtitle, From Prehistory to Global Crisis, indicates what he thinks the consequences are today of this deforestation. No solutions to this crisis are really offered, but perhaps any solutions if they arise are likely to do so as more people become informed about this significant global problem.

Because the book is so dense with information, it is not an easy or quick read, which is unfortunate because the details are so significant and numbing. But, this book is an extraordinary summary that all conservation-oriented people should read as much of, and as often, as possible.