LEARN · PRACTISE · DISCOVER
Biodiversity and Conservation
Biodiversity, short for biological diversity, is the variety of life on Earth. Scientists have described around two million species so far, and many more remain undiscovered. Biodiversity is not just about rare animals in faraway places; it supports the food we eat, the water we drink and the air we breathe. In this lesson you will learn why biodiversity matters, what threatens it and how conservation works.
Three levels of biodiversity
| Level | Meaning | Example |
|---|---|---|
| Genetic diversity | variety of genes within a species | different varieties of rice or apples |
| Species diversity | variety of species in an area | the many insects in a meadow |
| Ecosystem diversity | variety of habitats in a region | forests, wetlands and grasslands in one country |
Why genetic diversity matters
Populations with more genetic variety are more likely to include individuals that can survive diseases or environmental changes. In the 1840s, Ireland relied heavily on a small number of potato varieties. When a plant disease spread, it destroyed much of the crop, contributing to the devastating Great Famine. Low genetic diversity made the food supply vulnerable.
Why biodiversity matters
Healthy, diverse ecosystems provide ecosystem services, benefits that people receive from nature:
- Provisioning: food, fresh water, timber, fibres and medicines
- Regulating: pollination of crops, water purification, flood control, climate regulation
- Supporting: soil formation and nutrient cycling
- Cultural: recreation, inspiration, spiritual and cultural value
Example: pollinators
Many of the world’s crops, including many fruits, vegetables and nuts, benefit from animal pollinators such as bees, butterflies, birds and bats. Declines in pollinators can affect both biodiversity and food production.
Medicines from nature
Many medicines have been developed from natural compounds. For example, aspirin is related to a compound found in willow bark, and some cancer drugs were developed from plant compounds. Losing species can mean losing potential future medicines.
Threats to biodiversity
Scientists often summarise the main threats with the acronym HIPPO, plus climate change:
| Threat | Example |
|---|---|
| Habitat loss | clearing forests for farmland or building |
| Invasive species | non-native species that outcompete local ones, like cane toads in Australia |
| Pollution | pesticides, plastic and nutrient runoff |
| Population growth and consumption | rising demand for land, water and resources |
| Overharvesting | overfishing and illegal wildlife trade |
| Climate change | shifting temperatures and habitats faster than species can adapt |
A major 2019 global assessment by the scientific body IPBES estimated that around one million animal and plant species are threatened with extinction, many within decades, unless action is taken. Habitat loss is generally considered the largest driver on land.
How conservation works
Protecting habitats
Protected areas, such as national parks and marine reserves, safeguard habitats. In 2022, nearly 200 countries agreed to the Kunming-Montreal Global Biodiversity Framework, which includes a target to conserve 30 percent of land and sea areas by 2030, often called “30 by 30”.
Restoring ecosystems
Restoration means helping damaged ecosystems recover, for example replanting native forests, removing invasive species or restoring wetlands.
Protecting species
Laws and agreements protect endangered species and regulate trade. The international agreement CITES regulates trade in wild animals and plants. Captive breeding programmes have helped species such as the California condor and the Arabian oryx recover.
Example: a conservation success
Humpback whale populations were severely reduced by commercial whaling. After international protections in the twentieth century, many humpback populations have recovered substantially. This shows that well-designed, enforced protection can work.
Community-led conservation
Conservation is often most successful when it involves local and Indigenous communities, who frequently have deep knowledge of their land and a strong interest in managing it sustainably.
What you can do
- Plant native species in gardens or school grounds to support local insects and birds.
- Never release pets or aquarium plants into the wild, as they can become invasive.
- Join citizen science projects, such as bird counts or wildlife-recording apps, which help scientists track species across huge areas.
- Reduce waste and choose sustainably sourced products, such as certified seafood or wood, where possible.
Small local actions add up, and the data collected by citizen scientists is used in real research. Many important discoveries about bird migration and insect decline have relied partly on records collected by volunteers.
Key takeaways
- Biodiversity includes genetic, species and ecosystem diversity.
- Ecosystems provide services such as food, clean water, pollination and medicines.
- Major threats are habitat loss, invasive species, pollution, population and consumption, overharvesting and climate change.
- Protected areas, restoration, laws and community-led efforts help conserve biodiversity.
Practice
1. Name the three levels of biodiversity. 2. Give two examples of ecosystem services. 3. Which threat is generally considered the biggest driver of biodiversity loss on land? 4. Describe one conservation success.
Answers: 1 genetic, species and ecosystem diversity. 2 for example, pollination, clean water, flood control or medicines. 3 habitat loss. 4 for example, the recovery of humpback whales after whaling protections, or captive breeding of the California condor.