Biodiversity

By Maryam Nazir Chaudhary

Introduction

The U.S. Museum of Natural History states that ‘the term biodiversity (from ‘biological diversity’) refers to the variety of life on Earth at all its levels, from genes to ecosystems, and can encompass the evolutionary, ecological, and cultural processes that sustain life. Biodiversity includes not only species we consider rare, threatened, or endangered, but also every living thing — from humans to organisms we know little about, such as microbes, fungi, and invertebrates’. Thus, biodiversity embodies the variety of life on our planet. Although the beauty of nature alone is appreciable, biodiversity is crucial for our own survival.

Ecosystem Services

Regardless of how ‘developed’ and ‘modernised society has become, mankind still remains dependent on the earth’s biological and geochemical systems. We depend on plants for oxygen, fertile soil for agriculture, insects for pollination and much more. Wetland ecosystems act as a natural filtration system, absorbing toxins and chemicals from the environment. From a healthcare perspective, a staggering 50,000-70,000 different plant species are harvested for use in modern and traditional medicine. In terms of food security, 100 million metric tonnes of aquatic life are taken from the wild every year. This phenomenon is known as ecosystem services or, as defined by the National Wildlife Federation, ‘any positive benefit that wildlife or ecosystems provide to people’.

According to the International Union for Conservation of Nature (IUCN), the monetary value of goods and services provided by ecosystem services amount to a whopping 33 trillion USD per year . Biodiversity is also crucial for climate change mitigation – Canada’s national parks store 4.43 gigatonnes of carbon, a service worth up to 2.2 trillion USD, depending on the price of carbon in the market. Biodiversity is inextricably linked to us and its loss will also mean the loss of indispensable ecosystem services.

Impact of Human Society

Humanity now finds itself in the midst of a sixth extinction, with biodiversity dropping rapidly across the world. Peer-reviewed research has found that ‘the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate’. Of 177 different mammalian species, nearly all had lost, at the very least, 30% of their territory between the years 1900 and 2015, whereas more than 40% of those species underwent severe population declines. One of the authors of the study, Gerardo Ceballos, said regarding his team’s findings: ‘what is at stake is really the state of humanity’.

On top of that, it is humanity itself that is largely responsible for this global catastrophe. Anthropogenic greenhouse gas emissions have long been established as the main contributor to rising carbon dioxide levels and subsequent global warming. Many animals will be unable to adapt to this rapid change in the earth’s climate and will ultimately die out. For example, ocean acidification due to excess atmospheric CO2, endangers the survival of coral reefs as it increases the energy required for calcification. A study found that 10 out of 18 species of calcifiers exhibited reduced rates of net calcification under low pH.

Not only is climate change radically altering habitats and damaging entire ecosystems, but humans are also directly killing various different species. Throughout history, humanity has displayed incredibly selfish behaviour, having driven several animals to extinction, from the dodo bird to the Tasmanian tiger, as well as having destroyed entire landscapes like in desertification. The great auk, a close relative of modern-day penguins and native to the North Atlantic coastal waters, was also driven to extinction by heavy human exploitation. A study states that it ‘was killed and eaten and exploited for other products such as feathers’.

Invasive species introduced by man also have disastrous effects on the local animals and ecosystem. Research has found that the chytrid fungus Batrachochytrium dendrobatidis (Bd) has driven the decline of at least 501 amphibian species, including 90 presumed extinctions. This fungus was most certainly brought to the amphibian-rich Panama by humans; studies attribute its spread to international trade that began in the mid-1930s. Similarly, the fungi Geomyces destructans, which was most likely imported from Europe, continues to wipe out American bats. It is clear that mankind is responsible for the massive drop in biodiversity observed in recent years.

Moving Forward

Biodiversity connects all of nature and as such we are wholly dependent on it. Several completely different and diverse species are interconnected and depend on one another for their survival. For example, Eciton burchellii army ants support and live in association with more than three hundred diverse species, including opportunistic and obligate ant-follower birds, butterflies, such as skippers, and mites. It is crucial that we address biodiversity loss immediately, as all evidence points towards a disaster if we do not. By killing off microbes that digest waste, plants that provide oxygen and others, we are destroying our very own chances of survival. If we do not rectify our reckless behaviour, mankind will very well bring on its own demise.