Feedback loops: Regulating natural processes

When it gets really cold, what happens to your body? First you start shivering. Then, if you don’t take the hint and get warm, some of your body parts become numb. Keep this up, and soon, it’ll become blue. So will your mood.

Similarly, what happens when it gets really hot? You sweat. You sweat some more. If you don’t get cool, soon you’ll start to feel faint. You might actually faint.

All of this is part of a mechanism in our body. We are warm-blooded creatures, and our body has the ability to maintain its internal temperature. It also maintains the pH of fluids in our body.

Such processes are not restricted to humans, or even specific organisms. Increase the scale, and you will find such regulation of features even within a population or in an ecosystem. This ability to regulate an environmental process is solely because of a concept called feedback mechanism (or feedback loops).

Feedback-what are they?

In simple English, it means to tell someone/something about the its positives and negatives after analysis. It helps us improve (or in other words, regulate) our activities.

In Ecology, the definition is somewhat similar. Feedback is a natural mechanism by which nature analyses and regulates natural phenomena. Any feedback requires forcing (in other words, the activity or object). This forcing is what begins the feedback process. In the above example, extreme cold or extreme heat was the force. It initiates the feedback response from the entity.

Positive and negative feedback

Any forcing elicits a response from that system. Depending on the response, a feedback can be negative or positive. Negative feedback tends to reduce the initial forcing. In the above example for extreme cold, the body began shivering as a response to the forcing. This was a feedback, that increased body activity and generated heat. This reduced the impact of extreme cold.

negative-feedback
Negative feedback loop.

Positive feedback, on the other hand, increase the initial forcing. Take the example of heavy rains causing soil erosion. Heavy rain is the forcing. Due to this, infiltration rate is low and water begins to accumulate on the surface. This leads to soil erosion. When the soil gets eroded, it exposes the bare rock below. This rock has absolutely minimal pore space, because of which infiltration is even lower, leading to easier flow of water. This in turn, increases soil erosion.

positive-feedback
Positive feedback loop.

Examples of positive and negative feedback are abundant in nature. Everywhere a process needs regulation, you will find either a positive or a negative feedback loop.

Feedback as a landscape process

First, it is important to recognize that feedback works within an “environment”. This is a flexible term. Environment can be defined on various scales. And at every one of these scales, you will observe feedback mechanisms. Therefore, this process is fundamentally a landscape phenomenon (remember, landscape does not have to mean a very large system).

Second, feedback simplifies the working of nature by making a few aspects of the environment the “controllers” of a particular natural phenomena. By studying and understanding these influences, we can glean a lot about that process, even if we are unable to look at all the factors in play. The “controlling influences” have such a large effect on the phenomenon, that the drawback of cybernetics is overruled in our studies.

(Feedback is an important principle behind cybernetics. It is not just used in ecology, but in other fields of cybernetics applications as well.)


In a series of posts on feedback, I’ll cover concepts like homeostasis, it’s applications and need as well as positive feedback mechanisms and how it results in the world that we see around us.

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