Nature Hates a Monoculture

By Ian Rose
Published January 5, 2020
Categories: None

"Nature abhors a vacuum." Aristotle observed that wherever nature found a void, it started working immediately to fill it. He was even more right than he realized, because nature doesn't just hate nothing. It also hates a place with only one thing.

A more accurate and modern version of Aristotle's postulate might be "Nature abhors simplicity." Diversity and complexity are nature's calling cards, and even though some natural environments, like deserts and the high Arctic, can seem simple to our eyes, they are still much more diverse than the simplified environments modern humanity has created.

One obvious example is a lawn - nothing but one species of grass, usually introduced. But also, take a modern industrialized farm. When you think of farms, you may want to picture a diverse garden stretching as far as the eye can see, but the reality is much more often a monoculture, one species, usually of a cereal grain like corn or wheat, dominating hundreds or thousands of acres.

This is the opposite of a natural landscape, and that has all sorts of consequences.

Monocultures are Fragile

A monoculture is like a bar stool with only one leg. If there is only one species of plant dominating a landscape, and often only one variety of that plant, the limits of the entire ecosystem are going to be the limits of that one plant. Temperature, moisture, disease, predators - if just one of these pushes the boundary of that one plant's tolerance, the whole system can collapse.

Monocultures are Expensive

We too rarely consider or appreciate how much we get for free from our environment. Air and water are the obvious examples of what modern resource managers call "ecosystem services", but there are more, like pest control, soil conservation, erosion prevention, and more. These are the benefits of a diverse, natural environment. A monoculture works differently.

Pests get out of control easily on a single-species crop. Soil erodes constantly. Water is a constant struggle - sometimes too little, sometimes too much. The greatest ecosystem service of all is balance, and balance requires diversity.

We have tools for compensating for the imbalance of monoculture, but none of them are perfect replacements. Pesticides can prevent certain pests, but often have unintended consequences for water, soil, and non-target organisms. Intensive irrigation can fill in when water is low, but isn't much help when it floods.

In the end, the tools of modern agriculture can be incredible additions to farming yield, but are often used as poor replacements for things that a more natural system offers us for free. They have allowed us to feed billions of people, but at a growing cost to our water, air and climate.

Monocultures are Temporary

A monoculture is always in the process of being broken. Every day you aren't spraying or tilling or otherwise actively taming the land, it is trying to get back to a more natural state. Pioneer plants, which we tend to call weeds, are always invading, because we give them bare ground, just like the natural disturbances they evolved to exploit.

This is actually the most hopeful thing about a monoculture. It wants to be more diverse. Lessen the pressure just a little, and diversity will find it. This passive option can be dangerous, because the species most likely to invade are the most opportunistic ones, not necessarily those most useful to us, but it shows that monoculture is not a one-way street. It is reversible, and when we apply our knowledge and power to supporting diversity rather than denying it, we can actively grow diverse, productive land that also serves our needs.

Monoculture is a Choice

We humans have enormous power. Too often, we use it for destructive purposes, but there is nothing inherently bad about the ability to affect our environment. We chose to force monocultures on the world, and we can choose other ways of feeding and supporting ourselves. Ideally, we would make that choice with the good of all species in mind, but that doesn't tend to be our nature. Luckily, we have enough information now to know that what is good for the world and our fellow species is also in our own long-term best interest. Diversity is a survival tactic, and if there is one thing we have been good at so far in our history, it's surviving.