free html hit counter Peak Oil Debunked: 108. LIEBIG'S LAW AND SUCCESSION

Wednesday, September 21, 2005


Liebig's Law is a perennial favorite in die-off circles. The law states that the population of a species is constrained by whatever essential resource is in shortest supply.

Here's a classic statement by Jerry Abbott, a peak oiler over at
Every species of living organism follows a characteristic pattern of population growth. If the species' numbers are not limited by predators, then they will be limited by the full utilization or by the depletion of the first essential resource to fall into short supply. Often, that resource is food.

When caribou were introduced to a Canadian island years ago, they had much moss to eat. But there were no wolves on the island, so over the years the caribou kept munching on moss and breeding up more caribou. The herd grew in numbers. Then, one year right before winter, one of the caribou ate the last mouthful of moss. Canadian foresters were able to save the last three dozen animals of what had been a herd of thousands.

The end came swiftly. A generation before the end, there was no obvious sign that the end was near.

That is where we are with the energy resources we require to grow our food. Source

Doomers portray Liebig's Law as the mechanism of collapse, the executioner of species which have gone into overshoot, but this is a biased oversimplification.

In his book "How Many People Can the Earth Support?", Joel E. Cohen goes into great detail on Liebig's Law, and this part is especially interesting:
But natural communities are far more complex than the monocultural experiments on which the law of the minimum [i.e. Liebig's Law] is based. Different species have different requirements for a given element, as Liebig knew. Consequently, when one element is limited in a community of species, population growth typically does not grind to a halt; rather, a species that is less constrained by that limiting element replaces another that is more constrained in a process called succession.
This observation is extremely important when Liebig's law of the minimum is used to think about human carrying capacity. For humans, different technologies, like different species in nature, are ways of extracting life from the physical, chemical and biological environment. In ecological succession, as time passes some species become less abundant and other species become more abundant, in a more or less repeatable pattern. Analogously, in human ecology, some technologies decline and are replaced by others. The changes in technologies imply changes in how people live and how they make a living, but do not necessarily imply constraints on human numbers.(P. 242)
Here's a more detailed variation of the same concept:
Conclusion: Collapse as a Succession Process

Even within the social sciences, the process by which complex societies give way to smaller and simpler ones has often been presented in language drawn from literary tragedy, as though the loss of sociocultural complexity necessarily warranted a negative value judgment. This is understandable, since the collapse of civilizations often involves catastrophic human mortality and the loss of priceless cultural treasures, but like any value judgment it can obscure important features of the matter at hand.

A less problematic approach to the phenomenon of collapse derives from the idea of succession, a basic concept in the ecology of nonhuman organisms. Succession describes the process by which an area not yet occupied by living things is colonized by a variety of biotic assemblages, called seres, each replacing a prior sere and then being replaced by a later, until the process concludes with a stable, self-perpetuating climax community (Odum 1969).

One feature of succession in many different environments is a difference in resource use between earlier and later seres. Species characteristic of earlier seral stages tend to maximize control of resources and production of biomass per unit time, even at the cost of inefficiency; thus such species tend to maximize production and distribution of offspring even when this means the great majority of offspring fail to reach reproductive maturity. Species typical of later seres, by contrast, tend to maximize the efficiency of their resource use, even at the cost of limits to biomass production and the distribution of individual organisms; thus these species tend to maximize energy investment in individual offspring even when this means that offspring are few and the species fails to occupy all available niche spaces. Species of the first type, or R-selected species, have specialized to flourish opportunistically in disturbed environments, while those of the second type, or K-selected species, have specialized to form stable biotic communities that change only with shifts in the broader environment (Odum 1969).Source
This is something the doomers always leave out in their treatment of Liebig's Law. In nature, resource constraints lead not to die-off, but to succession, where more complex, resource-conserving species steal the niche of the wasteful species that preceded them. Countries, people and technologies which do not depend on oil will thrive during peak oil -- growing into the niches vacated by the withering oil-dependent "species".


At Thursday, September 22, 2005 at 8:14:00 AM PDT, Anonymous Anonymous said...

Doomers have the tendency, I've noticed, to treat various "laws of nature" (2nd Law of Thermodynamics, Liebig's Law, Jevons' Paradox) as gospel that are actually, well, not. Nice post.

At Thursday, September 22, 2005 at 5:33:00 PM PDT, Blogger JD said...

How did you come to the conclusion from comparing Cohen to Liebeg that a society going from complex to simple does not require large casualties.

What makes you think society will go from complex to simple? As an ecosystem progresses through the stages of succession, the organisms progress from simple to complex. Greater complexity is needed to use resources more efficiently.

Whether the new "species" or "society" or whatever you want to call it, is better, well I guess to the survivors it would be. But I bet its not better for the "species" that gets the boot.

The "species" in the case of peak oil are societies which use oil with varying degrees of efficiency. As oil gets expensive, this will place a tremendous burden on heavily addicted countries like the U.S. This stress will hinder the U.S., and allow other countries (or even other approaches/technologies within the U.S.) to steal the niche of the fuel hogs. The fuel hogs will be spending so much of their resources on fuel, that they won't have much left over to defend themselves against less dependent competitors.

It's a form of technological/economic succession. People aren't going to die; lifestyles and approaches are going to die.


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