A toolbox, not a tool

Whole Earth, Winter, 2001 by Toby Hemenway

Greg Williams has written a passionate, articulate and--to the non-ecologist--persuasive critique of permaculture. So persuasive, in fact, that it sent me scampering to a basic ecology text to confirm that his central premise--that meadows and farms are more productive than forests--is completely wrong. His other claims--that my book is based on wishful thinking rather than research, and that there are no data to support permaculture--are equally incorrect.

Permaculture occasionally triggers a strong emotional response, which is the reason I suggested (unsuccessfully) to my publisher that my book's title not include the word, and why in the text I use the terms "ecological gardening" and "sustainable landscaping" almost interchangeably with permaculture.

The field has gained infrequent attention from both mainstream and alternative press. In part, this neglect is because permaculture's cofounder, Bill Mollison, is a brilliant but angry man who often deliberately alienates both critics and adherents (he attempted to suppress my book via threats of a copyright lawsuit; hardly the way to see one's ideas promoted). Indeed, Williams acknowledges he has been personally offended by Mollison.

But more importantly, permaculture suffers because it can't be defined in a sound bite--the kiss of death in a fast-food culture. Williams gives the impression that permaculture is essentially forest gardening. It's not. Permaculture is a broadscale design system that organizes concepts, principles, techniques, and strategies from many well-established fields into a pattern of mutually supportive relationships. If organic gardening, solar power, agroforestry, and other disciplines can be thought of as tools, then permaculture is a toolbox in which they can be organized for best use. Permaculture is a meta-discipline, operating at a higher level than that of technique. It has been used to design successful landscapes, houses, villages, businesses, farms, and developments. Permaculture is founded on the belief that if we identify and use the appropriate principles from natural systems, we can finally begin to develop a coherent science of design, something strangely lacking in a species that supposedly designs its environment.

Because it is a broad design science, I've heard novice practitioners say "permaculture includes organic gardening (or straw-bale building, or consensus decision-making, or co-housing)," which can sound arrogant. This perceived omnivorousness aggravates specialists such as Williams who have painstakingly developed unique disciplines only to see them apparently subsumed under "permaculture." But permaculture is not a rival: it merely helps apply knowledge intelligently.

Permaculture's nature-derived design principles include suggestions such as "use elements with multiple functions" and "recycle materials on site." I searched in vain among my list of principles for what Williams says is at the foundation of permaculture, namely that mature ecosystems are more productive than immature ones. Since this supposed dogma forms the heart of Williams's critique, we should examine it.

When Bill Mollison said that a forest was more productive than farm. land, Williams disagreed, not because he had any data--he couldn't have, since as we shall see, they support Mollison--but because the statement contradicted his chain of reasoning about ecological succession. This misguided syllogism goes:

(1) Mature ecosystems are less productive than young ones;

(2) Forests are more mature than the meadows that farmland imitates;

(3) Thus forests must be less productive than meadows and farms.

But Williams fails to note the difference between "mature" and "more mature." A meadow is an example of an extremely immature successionary stage. A forest spans successionary stages from early through middle to late or mature. Williams fastens upon this late, less-productive phase, ignoring the fact that a developing forest (and by extension, a designed forest garden) may pass through eighty to 250 years or more of enormous productivity in early and middle stages before declining into senescent, late maturity, if it ever does reach late maturity (that elusive "climax" phase).

Williams offers no data to support his notion that forests aren't productive. He ignores all the research that shows forests are more productive than meadows and farms. The classic book, Communities and Ecosystems, by renowned ecologist Robert H. Whittaker, cites a benchmark study showing that in temperate deciduous forest, net primary productivity (NPP), the measure that Williams favors, is 1,200 grams of carbon per square meter per year, while temperate grassland NPP is only 600 gm/[m.sup.2]/yr. Whittaker's data appear in dozens of introductory textbooks. In 1975, David Reichle (Bioscience 25:257) showed that forest NPP can be ten times that of a meadow. NPP of farmland, as several other studies show, is only 200-800 gm/[m.sup.2]/yr, and it achieves that only with vastly greater inputs than a natural ecosystem.