What is Biodiversity? A Look into Its Definition and Significance

Life on Earth exists in countless forms, from microscopic bacteria to towering trees, from tiny insects to massive whales. This incredible variety represents biodiversity, one of the most fundamental concepts in understanding our planet’s health and our own survival. But what exactly is biodiversity, and why does it matter so much?

Understanding biodiversity 🔗

Biodiversity refers to the variability among living organisms from all sources, encompassing everything from genes to entire ecosystems. The term itself combines “biological” and “diversity,” capturing the essence of life’s variety on Earth.

Biodiversity includes all living things: the different plants, animals, fungi and microorganisms, the genetic information they contain, and the ecosystems they form. This definition highlights that biodiversity is not just about counting species but understanding the complex web of relationships that sustain life.

Scientists typically examine biodiversity at three interconnected levels, each essential to the functioning of our planet’s ecosystems.

Genetic diversity 🔗

Genetic diversity represents the variety of genes within a species. Each individual organism carries a unique genetic makeup, and different populations of the same species may have distinct genetic compositions. This variation is crucial because it allows populations to adapt to environmental changes through the survival and reproduction of individuals with particular genetic characteristics.

Consider the importance of genetic diversity in crop production. Thanks to this variety, farmers have been able to develop productive crops suited to different climates and resistant to various diseases. However, the demand for high-yield varieties has resulted in significant losses. Without adequate genetic diversity, populations become vulnerable to disease and environmental changes, increasing the risk of extinction.

Species diversity 🔗

Species diversity measures the number and variety of different species found in a given area. A lush tropical rainforest has much higher species diversity than a sandy desert, where only select species can survive harsh conditions.

This type of biodiversity is fundamental to the functioning of natural systems that support life. Species-rich habitats tend to be more adaptable and productive, with greater resistance to challenges like erosion and environmental stress. While mammals often capture our attention, they make up less than one percent of all animal species. Invertebrates, particularly insects, dominate the animal kingdom and fill vital roles as pollinators, nutrient recyclers, and food sources for other species.

Ecosystem diversity 🔗

Ecosystem diversity refers to the variety of different habitats, communities, and ecological processes across a landscape. From rainforests to deserts, from wetlands to coral reefs, Earth’s landscapes display remarkable variation. An ecosystem can cover a large area, such as a whole forest, or a small area, such as a pond.

This rich variety of habitats forms the foundation for strong species and genetic diversity while providing ecosystem services that benefit the entire world. Peatlands filter water and absorb carbon from the atmosphere, preserving water quality and mitigating climate change. However, as weather patterns shift and vast areas are converted for agriculture, ecosystem diversity faces serious threats.

The 1992 Earth Summit definition 🔗

The concept of biodiversity gained international legal recognition at a landmark event in environmental history. The Convention on Biological Diversity was opened for signature at the Earth Summit in Rio de Janeiro on June 5, 1992, marking the first time that biodiversity conservation was recognized as a common concern of humankind in international law.

This historic convention established three main goals: the conservation of biological diversity, the sustainable use of its components, and the fair and equitable sharing of benefits arising from genetic resources. The agreement covers all ecosystems, species, and genetic resources, linking traditional conservation efforts to the economic goal of using biological resources sustainably.

By the end of 1993, 165 countries had signed the Convention, demonstrating unprecedented global commitment to protecting biodiversity. The treaty recognized that biological diversity is an integral part of the development process, setting principles for sharing benefits from genetic resources, particularly those destined for commercial use.

Why biodiversity matters 🔗

Biodiversity is not merely an abstract scientific concept. It plays a crucial role in sustaining ecosystems and human life in tangible, measurable ways.

Essential ecosystem services 🔗

Healthy communities are sustained by well-functioning ecosystems, which provide critical services such as clean air, fresh water, natural medicines and food security. These ecosystems also regulate diseases and help stabilize the climate.

Consider the role of forests, which absorb over 2.6 billion tonnes of carbon dioxide annually, contributing to climate regulation and reducing pollution-related diseases. Wetlands perform vital functions in filtering water pollutants, yet 35 percent of global wetland coverage has been lost since 1970, increasing waterborne diseases and reducing water availability for over 2 billion people.

Food security and nutrition 🔗

More than 75 percent of global food crops rely on animal pollinators, contributing hundreds of billions of dollars annually to global agricultural output. Much of our food exists because of the ecological services of pollinators. The decline in bee populations threatens not only agricultural productivity but also global food security and nutrition.

Biodiversity supports healthy, sustainable food systems by providing a diverse range of plant and animal species. This diversity affects the nutritional composition of food and offers a genetic pool for developing crops and livestock resistant to pests, diseases, and climate extremes.

Medicine and health research 🔗

Over 50 percent of modern medicines are derived from natural sources. Aspirin originated from willow tree bark, while treatments for serious diseases have come from unexpected sources like the rosy periwinkle flower. Traditional medicine, which is utilized by 60 percent of the world’s population, relies heavily on medicinal plants obtained through wild collection and cultivation.

Significant medical and pharmacological discoveries are made through greater understanding of Earth’s biodiversity. The biological diversity of microorganisms, flora, and fauna provides extensive benefits for biological, health, and pharmacological sciences.

Disease regulation and prevention 🔗

Biodiversity plays a crucial role in disease regulation by maintaining balanced ecosystems where no single species dominates. This balance helps limit the spread of infectious diseases. Over 75 percent of emerging infectious diseases are zoonotic, jumping from animals to humans, and often arise in areas where ecosystems have been disrupted by deforestation or land-use change.

By maintaining biodiversity, ecosystems can buffer humans from exposure to disease reservoirs. However, human activities that disrupt biodiversity, including deforestation, habitat fragmentation, and climate change, alter ecological interactions and ultimately impact disease patterns.

Climate stability 🔗

Ecosystems such as forests and wetlands act as natural carbon sinks, absorbing carbon dioxide and regulating global temperatures. The destruction of these ecosystems accelerates climate change, leading to increased heatwaves, floods, and other climate-related health risks.

Climate change, in turn, affects biodiversity through extreme weather events that influence ecosystem health and productivity. Marine biodiversity faces threats from ocean acidification related to atmospheric carbon levels, while longer-term climate changes affect the viability of ecosystems and shift the distribution of plants, animals, and even human settlements.

Economic value 🔗

The economic consequences of biodiversity loss are profound. The global economic impact of biodiversity loss is estimated at 10 trillion dollars annually, including healthcare costs from increased disease transmission and agricultural losses from pollinator declines. Conversely, insect pollination services alone are valued at tens of billions of dollars per year in many regions.

Indigenous Peoples, representing approximately 6 percent of the global population, manage over 38 million square kilometres of land globally, which includes nearly 40 percent of all protected areas. They are crucial stakeholders and rights holders in the conservation and sustainable management of biodiversity.

Current threats to biodiversity 🔗

Despite its importance, biodiversity is declining at an alarming rate. Species extinctions are currently occurring 10 to 100 times higher than natural baseline rates, largely due to human activities. Deforestation, habitat fragmentation, climate change, pollution, and invasive species all contribute to this crisis.

Invasive alien species alone contribute to 60 percent of species extinctions, causing over 400 billion dollars in global economic damage each year. Approximately 1 million species are at risk of extinction, threatening vital ecosystem services and exacerbating public health risks globally.

The best approach to conserving biodiversity involves saving habitats and ecosystems rather than focusing solely on individual species. When a species is at risk, the habitat in which it lives is usually under threat as well. No organism exists in isolation, and protecting entire ecosystems ensures the survival of countless interdependent species.

What do you think? How might your daily choices impact biodiversity, and what small changes could you make to help protect the variety of life on Earth? In what ways do you think your local community depends on biodiversity for health and wellbeing?

References

1. https://www.who.int/news-room/fact-sheets/detail/biodiversity
2. https://australian.museum/learn/science/biodiversity/what-is-biodiversity/
3. https://www.ifad.org/en/w/explainers/the-three-types-of-biodiversity-explained
4. https://en.wikipedia.org/wiki/Convention_on_Biological_Diversity
5. https://en.wikipedia.org/wiki/Convention_on_Biological_diversity
6. https://www.nps.gov/subjects/biodiversity/services-provided-by-biodiversity.htm