The Three Components Of Biodiversity

Have you ever heard the saying “variety is the spice of life”? Well, it turns out variety is more than spice. It is what ensures the continuity of life. Biological diversity encapsulates the variability of life forms, ecological processes, and biotic communities on Earth. Biodiversity can be complex. However, this article offers a brief description by focusing on the components of biodiversity.

Related Read: Biodiversity Facts & Statistics.

What is biodiversity? 

Biodiversity refers to the variability of living organisms and their environments. It considers the variations that occur at all levels of biological organization. In other words, it is the totality of the differences between and within species or ecosystems.

Biodiversity is why we have different microorganisms, plants, and animals. It also explains why we can have different varieties within a single species. Furthermore, the fact that weather, soil conditions, and species distribution are not the same everywhere on Earth contributes to biodiversity.

The most common way to describe biodiversity is through species counts. That is, counting the species found in a particular place. The earth itself is a highly biodiverse place. Its rich biodiversity is what sustains life as we know it.

Why does biodiversity matter?

All living organisms are connected in such a way that they rely on other organisms and their physical environment to survive. This interdependence is highly complex, and despite years of scientific study, we have not fully understood it. 

We can be sure that every aspect of nature (living or not) is part of ecological processes that make life on Earth possible. Think of it this way: the earth is a giant machine that needs many parts working cooperatively to run well.

Biodiversity is why humans can enjoy a variety of foods. Medicinal plant species have played no small part in advancing human health. What about the many resources we get from the different parts of nature, like water, fuel, and timber?

One more great thing about biodiversity is how beautiful it makes our world. Various organisms have invaluable aesthetic and intrinsic value. The beauty of the world has benefits for our spiritual health as well.

Biodiversity is in danger.

A more biodiverse world should be something to aspire for. Still, many plants, animals, and even whole ecosystems are in danger of extinction.

Yes, biological communities have naturally changed over the years as new species developed and others became extinct. However, the current manner and rate at which species disappear is neither natural nor sustainable. Climate change, habitat destruction, diseases leading to population decline, and human-induced extinction are some threats to biodiversity.

We need to intensify and expand conservation efforts to protect the earth's biodiversity. Many biodiversity conservation campaigns focus on saving endangered species like the blue whale in isolation. However, a better approach would be to focus on all the components of biodiversity. 

What are the components of biodiversity?

Biodiversity occurs at three major levels: the ecosystem, species, and genetics. 

1. Ecosystem diversity 

In an ecosystem, living organisms interact with one another and their nonliving environment as a cohesive functional unit. The nonliving environment refers to minerals, nutrients, sunlight, soil, water, etc.

Ecosystem diversity refers to the different types and abundance of ecosystems on earth. It includes the variations and changes observed over time between ecological processes, biotic communities, and habitats. Having diverse ecosystems allows distinct life forms and abiotic factors to develop in different regions of the world.

Ecosystem diversity is the widest scale. It encompasses many more levels of biodiversity within it. In fact, smaller ecosystems exist within larger ones. For example, the earth is an ecosystem within which we have terrestrial and aquatic ecosystems. In the terrestrial ecosystem, there's the forest, which houses a meadow, a tinier ecosystem.

Regions of the earth with more ecosystem varieties offer more resources to help organisms thrive. That's why coral reefs, tropical rainforests, and sub-tropical regions are complex and support more species. Meanwhile, deserts, tundra, and Arctic regions have fewer species.

2. Species diversity

An ecosystem is home to a unique collection of species. A species refers to a population of organisms with specific characteristics that differentiate them from other species. Individuals within a species are typically able to procreate with other members of their species.

It's pretty hard for anyone to say with absolute certainty just how many plant and animal species are on earth. Currently, we estimate that there are about 8.75 million species on earth¹, with less than 20% named.

Species diversity describes the species (domesticated or wild) in a given ecosystem and their relative abundance. The more species there are within a geographical area, the more biodiverse the location is.

Here are some ways to think about species diversity:

Species richness - The count of different species found within a particular region. More species variety means high species richness and vice versa.

Species evenness - The relative abundance of different species found within a region. It indicates that one species does not numerically dominate the natural community.

Species richness and evenness are indicators of healthy species diversity.

3. Genetic diversity 

Genes are passed from parents to offspring, but they are not exactly copied and pasted. Genetic differences occur, distinguishing one individual from others within its species. It also differentiates one geographic population from another. Genetic variation is what eventually allows subspecies to form within a single species.

Genetic diversity refers to the variation of genes among individuals of the same species. It is also the genetic differentiation among populations of a single species. It describes how closely related or not members of a species are.

Genomes not only pass on physical appearance but also specific characteristics necessary for adaptation and survival. Resistance to pests and diseases, hardiness to withstand disturbance, or ability to survive droughts are some genetic traits.

Genomes can also pass on undesirable traits. When the gene pool is diverse, undesirable traits can be eliminated from entire species through natural selection. That is why high genetic diversity is essential to the survival of organisms. 

Large populations and high genetic diversity go together. Inbreeding occurs in small populations and lowers genetic diversity, typically passing forward undesirable genetics. That's why it is sometimes difficult to bring back species already on the path of extinction.

Final thoughts on the components of biodiversity 

The variability in our world is essential for maintaining the conditions that make our planet livable. Even the tiniest insects and other organisms not yet discovered play crucial roles. Overall, greater biodiversity in individuals, species, and ecosystems, the components of biodiversity, results in greater stability for humans and nature.