What is ecosystem homeostasis? In this lesson, we’ll talk about how ecosystems maintain their balance as populations cycle up and down, what it looks like when they do, and what it looks like when they don’t.
What Is Ecosystem Homeostasis?
Ecosystems are huge and complex. They contain networks of animals, from the largest mammals to the smallest insects, along with plants, fungi, and various microorganisms. All of these lifeforms interact and affect one another. Bears and birds eat the fish, shrews eat insects, and caterpillars eat leaves.
Everything in nature works in a delicate balance. But scientists like technical terms, so this balance of the organisms in an ecosystem is more commonly referred to as ecosystem homeostasis.Ecosystem homeostasis is all about equilibrium. When something is in equilibrium, it’s in balance. In the real world of ecosystems, nothing is ever perfectly balanced.
So an ecosystem in equilibrium is said to be in a relatively stable state. This means that the populations of various animals in the ecosystem are generally staying within a similar range. Populations can go up and down in cycles, as long as there isn’t a general upwards or downwards trend.
Conditions Gradually Change
However, the truth is that conditions in nature do change over time. Populations will go up and down. This happens as some species out-compete others, but it also happens because climates and landscapes change. Animals have to adapt to their surroundings.
But it’s important to realize that in nature, these things tend to happen slowly. Across geologic time, which is a fancy way of saying periods of time over which even rocks and landscapes change, systems that seem like they are in homeostasis will show themselves to not truly be such. When we talk about ecosystem homeostasis, we are focusing on a relative time frame. Now that we’ve established what ecosystem homeostasis is, let’s go through some examples of what equilibrium and non-equilibrium look like.
Equilibrium vs Non-equilibrium
So, what does equilibrium look like? Everything just staying the same? Not quite. For an ecosystem in homeostasis, things change all the time.
For example, let’s say we have a really simple ecosystem: lions eat gazelles, and gazelles eat wild grasses. If, in one particular year, the population of lions increases, the population of gazelles will decrease because there are more lions hunting them. With fewer gazelles, the population of wild grasses will increase.
The following year, perhaps there are no longer enough gazelles to feed the lions. That will cause the lion population to go down again, and with plenty of grass around, the gazelle population will boom. This will go back and forth in a continuous cycle. Since these cycles cause populations to move up and down within a particular range, this is an example of an ecosystem in equilibrium.Unfortunately for the natural world, examples of systems that are in non-equilibrium are easy to find. Due to the impacts of human activity – cutting down trees, releasing greenhouse gases that warm the planet, and hunting animals to excess – we are currently experiencing the fastest extinction event in history.
Whenever any animal goes extinct, or its numbers decline quickly, that is an example of non-equilibrium. For example, as of early 2016, there were approximately only 60 Amur leopards left in the world, as well as only 60 Javan rhinos.But an animal doesn’t have to go completely extinct for a system not to be in equilibrium.
If an animal disappears from a particular region or its population declines drastically, that has the effect of upsetting the equilibrium of the ecosystem and affecting all of the other animals in the food web. For example, people shot and killed all the wolves in many Western countries, causing booms in the deer populations. This made deforestation even worse, because deer tend to eat newly growing trees. Many forests in Western Europe and the United States either don’t regenerate naturally or regenerate very slowly because of this.The natural world has a beautiful and delicate balance, but that balance can easily be upset. The better we understand ecosystem homeostasis and all the complex, interconnected causes and effects, the more we’ll be able to predict the effects our actions will have.
Ecosystem homeostasis is equilibrium, or a balance of the organisms in an ecosystem. This means the populations of species in the ecosystem are relatively stable. Over time, these populations will change, but in the short term, they should move up and down in cycles around an average value.When an ecosystem is not in homeostasis, when it is in non-equilibrium, instead of populations moving up and down in cycles, they increase rapidly or plummet. For example, populations of huge numbers of species are decreasing rapidly due to human causes like climate change and deforestation.
The better we understand ecosystems, the more we’ll be able to understand and minimize our impact.