Explained: What does biodiversity mean?

What does ‘biodiversity’ mean?

‘Biodiversity’ means the variety and abundance of the world’s plants and animals. We refer to biodiversity on a global scale – for example when we talk about the one million species at risk of extinction – and at local level: a rainforest harbours tens of thousands of different species, making it rich in biodiversity, whereas a palm oil plantation often has only one type of tree and supports very few other species, meaning that it lacks biodiversity. Biodiversity loss is one of the biggest threats facing human and planetary health, yet it remains a largely undiscussed and unknown issue.

Why is loss of biodiversity bad?

Every species plays a role that is important for the survival of other species. Collectively, these mutually dependent life forms make up an ecosystem. An ecosystem: an ecosystem is a community of living things that all interact with one another. This is the web of life. Removing any part of this web will have a knock-on effect on the rest of it.

Here’s a popular example: when wolves were hunted out of Yellowstone National Park, the numbers of their main prey – elk – vastly increased. The growing population of elk ate more of the young willow and aspen trees. Shortly after, songbirds started to decline and the beavers – who relied on willow trees to survive in the winter – built fewer dams, in turn affecting freshwater fish. And the chain reaction went on.

As species go extinct, the complex and fragile connections within ecosystems are broken, causing a domino effect that threatens the survival of other species.

What are the causes of biodiversity loss?

The primary causes of biodiversity loss stem from human activity. Climate change, pollution and habitat destruction are some of the main reasons that species are going extinct. Here are some examples of the most problematic human activities causing biodiversity loss:

• Agriculture: Forests are cleared and wetlands are drained to make way for crops, plantations and livestock. Harmful pesticides used on crops are driving down insect populations, and the run-off is polluting rivers, threatening freshwater species.
• Overfishing: Overfishing means fish are being harvested from the ocean at a rate too high for stocks to replenish themselves. This is driving fish populations to dangerously low levels.
• Deforestation: Cutting down trees is driven by land clearance for farming, roads, housing developments and the timber industry. In 2021, the world’s lost forest area was greater than the size of the UK. Globally, forests are home to more than 80% of the world’s land-based plants and animal species.

Which region has the biggest loss of biodiversity?

According to the latest WWF Living Planet Report, Latin America and the Caribbean has suffered the largest declines in biodiversity anywhere in the world, with a 94% decrease between 1970 and 2018. The main cause of this dramatic decline is likely to be the destruction of the Amazon rainforest, which is seeing record-high rates of deforestation. Declines in this region are most severe in freshwater fish, amphibians and reptiles.