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Tonight is the Chinese Lunar Festival. Downtown in San Francisco's Chinatown, immigrants are exchanging moon cakes and telling tales of the Ghost Maiden who escaped as an orb in the sky. Twelve miles away where I live, I can walk in a cloud. The fog of the Golden Gate has piled up along the steep bank behind our house, engulfing our neighborhood in vapor. Under the light of Lady Moon, I take a midnight hike.

I wade chest-high in bleached ryegrass murmuring in the wind, and spy down the rugged coast of California. It is a disruptive land. For most purposes it is a mountainous desert that meets a generous ocean which cannot provide rain. Instead the sea sneaks in the water of life by rolling out blankets of fog at night. Come morning, the mist condenses into drops on the edges of twig and leaf, which tinkle to the earth. Much water is transported this way over a summer, bypassing the monopoly thunderclouds have on water delivery elsewhere. On this stingy substitute rain, the behemoth of all living things, the redwood, thrives.

The advantage of rain is that it is massive and indiscriminate. When it rains, it will wet a wide, diverse constituency. Fog on the other hand, is local. It relies on low-powered convection currents to ramble wherever it is easiest to drift to, and is then trapped by gentle, patient cul-de-sacs in the hills. In this way, the shape of the land steers the water, and indirectly, life. The correctly shaped hill can catch fog, or funnel drip into a canyon. A sunny south-facing mound will lose more precious moisture to evaporation than a shadier northern slope. Certain outcroppings of soil retain water better than others. Play these variables on top of each other and you have a patchwork of habitats. In a desert land, water decides life. And in a desert land where water is not delivered democratically, but parochially, on a whim, the land itself decides life.

The result is a patchwork landscape. The hills behind my house are cloaked with three separate quilts. A community of low-lying grass -- and of mice, owl, thistle, and poppy -- runs to the sea on one slope. On the crest of the hill, gnarly juniper and cypress trees preside over a separate association of deer, fox, and lichen. And on the other side of the rise, an endless impenetrable thicket of poison oak and coyote brush hides quail and other members of its guild.

The balance of these federations is kinetic. Their mutual self-supporting pose is continuously almost-falling, like a standing wave in a spring creek. When the mass of nature's creatures push against each other in coevolutionary embrace, their interactions among the uneven terrain of land and weather breaks their aggregate into local enclaves of codependency. And these patches roam over the land in time.

Wind and spring floods erode soils, exposing underlying layers and premiering new compositions of humus and minerals on the surface. As the mix of soil churns on the land, the mix of plants and animals coupled to it likewise churn. A thick stand of cactus, such as a Saguaro forest, can migrate onto or off of a patch of southwestern desert in little as 100 years. In a time-lapse film, a Saguaro grove would seem to creep across the desertscape like a pool of mercury. And it's not just cactus that would roam. Under the same time-lapse view, the wildflower prairie savanna of the midwest would flow around stands of oaks like an incoming tide, sometimes dissolving the woods into prairie, and sometimes, if the wildfires died out, retreating from the spreading swell of oak groves. Ecologist Dan Botkin speaks of forests "marching slowly across the landscape to the beat of the changing climate."

"Without change, deserts deteriorate," claims Tony Burgess, a burly ecologist with a huge red beard. Burgess is in love with deserts. He inhales desert lore and data all his waking hours. Out in the stark sun near Tucson, Arizona, he has been monitoring a desert plot that several generations of scientists have continuously measured and photographed for 80 years; the plot is the longest uninterrupted ecological observation anywhere. From studying the data of 80 years of desert change, Burgess has concluded that "variable rainfall is the key to the desert. Every year it should be a slightly different ball game to keep every species slightly out of equilibrium. If rainfall is variant then the mixture of species increases by two or three orders of magnitude. Whereas if you have a constant schedule of rainfall with respect to the annual temperature cycle, the beautiful desert ecology will almost always collapse into something simpler."

"Equilibrium is dead," Burgess states matter-of-factly. This opinion has not been held very long by the ecological science community. "Until the mid-1970s we were all working under a legacy which said that communities are on a trajectory towards an unchanging equilibrium, the climax. But now we see that it is turbulence and variance that really gives the richness to nature."

A major reason why ecologists favored equilibrium end points in nature was exactly the same reason why economists favored equilibrium end points in the economy: the mathematics of equilibria were possible. You could write an equation for a process that you could actually solve. But if you said that the system was perpetually in disequilibrium, you were saying it followed a model you couldn't solve and therefore couldn't explore. You were saying almost nothing. It is no coincidence, therefore, that a major shift in ecological (and economic) understanding occurred in the era when cheap computers made nonequilibrial and nonlinear equations easy to program. It was suddenly no problem to model a chaotic, coevolutionary ecosystem on a personal computer, and see that, hey, it acts very much like the odd behavior of a Saguaro forest or a prairie savanna on the march.

A thousand varieties of nonequilibrial models have blossomed in recent years; in fact there is now a small cottage industry of makers of chaotic and nonlinear mathematics, differential equations, and complexity theory, all this activity lending a hand in overturning the notion that nature or an economy seeks a stable balance. This new perspective -- that a certain unremitting flux is the norm -- has illuminated past data for reinterpretation. Burgess can display old photographs of the desert that show in a relatively short time -- over a few decades -- patches of Saguaro drifting over the Tucson basin. "What we found from our desert plot," Burgess said, "is that these patches are not in sync in terms of development and that by not being in sync, they make the whole desert richer because if something catastrophic wipes out one patch, another patch at a different stage of its natural history can export organisms and seeds to the decimated patch. Even ecosystems, such as tropical rain forests, which don't have variable rainfall, also have patch dynamics due to periodic storms and tree falls."

"Equilibrium is not only dead, it is death," Burgess emphasizes. "To enrich a system you need variance in time and space. But too much change will kill you too. You go from an ecocline to ecotone."

Burgess finds nature's reliance on disturbances and variance to be a practical issue. "In nature, it is no problem if you have very erratic production [of vegetation, seeds, or meat] from year to year. Nature actually increases her richness from this variance. But when people try to sustain themselves on the production from an ecosystem like a desert that is so variance driven, they can only do it by simplifying the system into what we call agriculture -- which gives a constant production for a variable environment." Burgess hopes the flux of the desert can teach us how to live with a variable environment without simplifying it. It is not a completely foolish dream. Part of what an information-driven economy provides us with is an adaptable infrastructure that can bend and work around irregular production; this is the basis for flexible and "just-in-time" manufacturing. It is theoretically possible that we could use information networks to coordinate the investment and highly irregular output of a rich, fluxing ecosystem that provides food and organic resources. But, as Burgess admits, "At the moment we have no industrial economic models that are variance driven, except gambling."