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Resilience and Stability: Scientific Reductionism Prevents a True Understanding of Populations

by on November 18, 2011

In the Article, “Resilience and Stability of Ecological Systems,” C.S. Holling describes how “traditions of analysis” in ecology are derived from physics (which infers the use of mathematical models). Such methodology focuses on quantitative over qualitative measurement, though the quantitative approach may not be sufficient for all divisions of ecology due to our tendency to connect stability to long-term survival when studying populations. C.S. Holling calls for a paradigm shift to a focus on what he calls “resilience” due to the existence of random events, nature of evolution, and limits of mathematical modeling, which prevent mathematical approaches from describing a population accurately. I believe that this shift is part of a larger paradigm shift within all disciplines of science. I believe that in a new age of science, most scientists will eventually discredit scientific reductionism (reducing all studied events to physics and math mechanics) and complexity theory may become the new standard as it is slowly incorporated into mainstream science. Ecologists, anthropologists, political scientists, biologists, chemists, etc. will recognize that not all the information that they obtain from observing the world can be reduced back down to math-based mechanics. Rather, subjective experience, stories, and qualitative data, will be respected in a new way because the concept of a novel, complex system emerging from simple atoms and molecules, will be a respected one.

Holling first describes some models used for tracking populations He describes some of the downsides to mathematical modeling including the fact that even the sophistication of the most complex models leaves out components vital for understanding long-term sustainability. As an example, an interaction between predator-prey, herbivore-foodsource, or two competing populations, could have large oscillations in their numbers the beginning and then the oscillations may slowly decrease over time as the populations reach stability or equilibrium. This is just one way or “domain” in which the system could operate. There are many other routes the model could take and new environmental conditions could shift the system into a different domain where the rules are new and a new mathematical model must be applied to the population system. Populations can shift from following a stable equilibrium model to an unstable equilibrium model or any other model; there is no one model that can account for all the factors in play in a natural landscape.

Holling says that mathematical modeling and therefore a focus on stable numbers and equilibrium is more of a “perceptual convenience” rather than a meaningful reality (p.1). It tells us nothing about the behavior of transient systems (and all natural populations are transient, he argues, “equally so under the influence of man” (p.2)). Populations fluctuate naturally and our first concern should be the conditions necessary for persistence. In fact,“It is at least conceivable that the effective and responsible effort to provide a maximum and sustained yield from a fish population or a non-fluctuating supply of water from a watershed (both equilibrium-centered views) might paradoxically increase the chance for extinctions.” (p.2) A system that is locally unstable can be globally stable and vice versa. A stable population can be very non-resilient (not adaptable to random fluctuations in the environment) and therefore at risk when mathematical modeling indicates otherwise.

Even though he’s critiquing mathematical modeling, Holling recognizes that the models can be useful and gives examples of where they work best and how they have been successful. Focusing on fresh water aquatic environments (due to the fact that they are the closest natural environments to “self-contained systems” where there aren’t too many external variables to prevent models from mapping accurately) he describes how there has, in fact, been consistency between actual recorded data and projected models, even with complicated human impacts such as pollution, sewage, construction, and fishing. He refers to these models as “more powerfully used as a starting point to organize and guide understanding” rather than taken as definitive (p.6).

Another factor he brings up is the randomness of nature. A random event, though it causes changes in a population, can actually create opportunity for the population to be successful:
“If we view the budworm only in association to its predators and parasites we may argue that it is highly unstable in the sense that populations fluctuate widely. But these very fluctuations are essential features that maintain persistence of the budworm, together with its natural enemies and its host and its associated trees. By so fluctuating, successive generations of forests are replaced, assuring a continued food supply for future generations of budworm and persistence of the system.” (p. 14) “…instability, in the sense of large fluctuations, may introduce a resilience and capacity to persist…. Moreover, if [the equilibrium-centered view] is used as the exclusive guide to the management activities for man, exactly the reverse behavior and result can be produced than is expected.” (p. 15)
Due to the nature of evolution, a population cannot develop resilience (and therefore persist long-term) if there are no factors pushing it to evolve new traits which allow it to survive: diversity and flexibility.

Finally, Holling proposes a measurement system for his new term “resilience” and suggest that it should be established separately from “stability” (which is semantically associated with mathematical equilibrium)). He does recognize that measuring stability is “unlikely” due to the amount of information that would need to be obtained first (p. 20). However, I believe that creating a mathematical model for resilience is, in a way re-establishing the limit of mathematics upon the field of ecology. Instead, I believe that the complexity of nature should be respected and qualitative data should be understood as valuable in itself to be used alongside physics and mathematics for a holistic, contemporary, ecological approach.

Works Consulted:
Holling, C. S. (1973). Resilience and Stability of Ecological Systems. Annual Reveiw of Ecology and Systematics, Vol. 4, p.1-23

1. As physics advances and Complexity Theory becomes more popular, will there will be a paradigm shift in the scientific community where “soft science” will be more appreciated and scientific reductionism will be discredited (allowing for qualitative data to have as much merit as quantitative)?
2. What is the true reason for tracking systems and populations and what is the value of knowing their persistence?
3. Is conservation always a good thing? Is it a good idea to attempt to change nature and keep species alive when the natural world doesn’t favor their existence?
4. What political influences (namely his understanding of the philosophy of science) that have shaped Holling’s view?


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  1. janellekramer permalink

    The third question is very interesting. Of course, some would say Yes, that conservation is always good. And others would say No, we should not attempt to save species when the natural order of things makes them endangered and finally extinct. However, it is hard to tell anymore what is affected solely by the natural world and what is affected by global warming and the human effects. I think it makes people feel better about global warming and all of the damage already caused when they put energy towards saving species and ecosystems, even when they are affected by lighting fires or other natural elements that have nothing to do with a human impact. My easy answer is that if something is truly nature-caused, then we should let the ecosystem and the species run their course. However, for a group of people to stand by and watch nature happen is easier said than done.

  2. After reading this article I found myself drawn to the third question as well. As mentioned already, it is very difficult and possibly near impossible to distinguish between what will happen naturally and what will not. I would argue that the need for conservation in certain areas and species is more common than to not have the need for conservation. I like how Hollings clearly outlined his idea of resilience and stability which led me to agree with Janelle’s post about what to conserve and what not to; but how can we define what is “truly nature-caused”? This allows room for opinions and subjectivity on what is in need of conservation.

  3. punam123 permalink

    The situation in which we are living right now requires conservation and protection of the extinct species. This 21st century where people are running like vehicles, moving with time. They do not care about the nature and the species living in the environment. We need to keep in mind about the future generation and their needs from the environment. People always get their basic needs from the environment. Despite of protection, many species are killed, some by natural cause and some by us. People do say that we should try to alter the law of nature because species who are going to live are going to live and who are going to die, they die. If we live in the world, where we have been altering the law through medicine and technology, then why not attempt to change the nature and keep species alive.

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