In the grand mosaic of life that blankets our planet, the most colourful and intriguing element is biodiversity. It defines the abundant variation and complexity of life forms that exist on Earth. Without biodiversity, the myriad of ecosystems that render our planet remarkably unique would falter, and life, as we comprehend it, would cease to persist.
The term "biodiversity" was first created in 1985 and it alludes to the extraordinary variety of life forms that inhabit every nook of our biosphere – in our oceans, forests, deserts, and even our cities. It encompasses the endless variations among plants, animals, and microorganisms and surpasses merely the number of different organisms. It's a concept that also signifies their relative frequencies, organisation at different levels, and interconnectedness within the ecosystem. The richness of biodiversity is critical not just for the ecological balance of our planet, but it also carries significant economic value, providing us with sustenance, shelter, fuel, clothing, and many other resources.
A word of caution!
This blog will examine the academic concept of biodiversity – not the concepts utilised within the metric. We have investigated these ideas in our other blogs. This piece is intended for individuals who have an interest in the academic concept of biodiversity.
The Many Aspects of Biodiversity
To comprehend biodiversity more profoundly, we delve into its three primary types: species biodiversity, genetic biodiversity, and ecological biodiversity. Each of these categories illuminates a different facet of life's diversity on Earth.
At the most basic level, species diversity refers to the variety of different species found in a specific area. It includes all life forms, from towering trees and colourful birds to invisible microorganisms. Each individual within a species is unique – for instance, humans show a vast diversity among themselves, with no two individuals being exactly alike - just look at fingerprints on your hands.
It is this richness and complexity of life forms, of species diversity, that lends robustness and resilience to our ecosystems.
This is where we can explore concepts like endemic species are the unique locals, found only in a specific location and nowhere else. They are like rare books available only in a particular library. Consider Hawaiian honeycreepers exclusive to Hawaii, Javan rhinoceroses that reside on the Indonesian island of Java, or marine iguanas only found in the Galapagos Islands. The occurrence of endemic species offers valuable insights into a region's ecological richness. It's worth noting, however, that these endemic species tend to be more vulnerable to human activity. They usually have a relatively smaller geographical range which can be easily ravaged by human activities. Thus, their presence or absence serves as a critical indicator of our ecological impact.
The foundation of biodiversity lies at the smallest level – the gene. ‘Genetic diversity’ refers to the variations in the genetic makeup of individuals within a species.
Just as every human has a unique genetic makeup leading to differences in appearance and attributes, there are different varieties within the same species of rice, wheat, maize, barley, and others. Genetic diversity is crucial as it contributes to species adaptation and survival in shifting environmental conditions.
Each species is a dynamic collection of individuals, each brimming with thousands of genes. Genetic diversity is the aggregate of these genes within a single species. You can visualise all the genes within a species as an expansive library of life codes; the more diverse the genes, the greater the genetic diversity, and thus, the more enriched the species in terms of biodiversity.
Broadening our scope, we observe biodiversity manifest in the variations in ecosystems themselves. Ecological biodiversity refers to the diversity witnessed among different ecosystems – from deserts, rainforests, and mangroves to man-made landscapes like urban parks and agricultural fields. Each of these ecosystems, teeming with life, is a unique assembly of living and non-living organisms interconnected through complex networks of relationships.
A geographical region, whether a petite landscape or a massive slice of a continent, is usually characterised by one or more ecosystems. The greater the variety of ecosystems, the higher the potential biodiversity as it can accommodate a wider array of species. Ecosystem diversity can, therefore, be an effective measure for a region's biodiversity.
Note that it's not just about the sheer number of ecosystems, but also the presence of unique ones that only exist in a specific region. Much like endemic species, these unique ecosystems represent a distinctive amalgamation of species with specialised adaptations and behaviours, forming a crucial part of the biodiversity puzzle. As we can see, these are very broad-ranging concepts – and pose big questions for how we can effectively measure biodiversity.