Biodiversity is the variety of all the species of organisms on Earth, or within a specific ecosystem. It includes not only the different types of plants and animals that make up an ecosystem, but also the genetic diversity within each species and the variety of ecosystems themselves.

The Earth supports a wide range of living organisms. There are many different plants and animals, as well as bacteria and fungi. Species depend on each other for:

  • Food
  • Shelter (e.g., birds nesting in trees)
  • Maintaining the environment (e.g. decomposers break down dead organisms)

An ecosystem with a high level of biodiversity contains many different species. In this type of ecosystem, each species is less dependent on another for the three factors. If a species dies out, it is less likely to affect the entire ecosystem. So, a high level of biodiversity makes an ecosystem more stable.

Human Impact on Biodiversity

However, human activities, such as deforestation, pollution and the introduction of invasive species, threaten biodiversity.

These activities can lead to the extinction of certain species and the disruption of ecosystems, which can have negative impacts on both the environment and human societies.


Forests are home to a wide range of species, many of which are found nowhere else on Earth. When forests are cleared, these unique species may be lost forever. Also, the loss of forests can disrupt the interconnected web of life that exists within them, as plants and animals rely on each other for survival.

  • For example, the loss of a particular plant species can affect the animals that rely on that plant for food.


Different types of pollution can have different impacts on biodiversity. For example:

  • Air pollution can damage plants and affect the respiratory systems of animals, making it more difficult for them to survive.
  • Water pollution can contaminate the water that plants and animals rely on for survival, leading to the loss of species.
  • Noise pollution can disrupt the behaviour of animals and make it difficult for them to communicate, mate, and find food.
  • Land pollution, such as the accumulation of plastic waste, can also harm plants and animals by destroying their habitats and making it difficult for them to survive.

Introduction of invasive species

Invasive species, often non-native, can outcompete native species for resources such as food, water, and habitat, leading to the decline or extinction of native species. They can also change ecosystems and disrupt the relationships between species, which reduces biodiversity.

Also, invasive species can have negative economic impacts, such as damaging crops and other valuable resources. The introduction of invasive species can be intentional or unintentional, and it is often the result of human activities such as trade and travel.

Maintaining biodiversity

There are several ways that humans are attempting to maintain biodiversity. Some of these include:

  • Protected areas – Establishing protected areas, such as national parks and wildlife reserves. These can help to preserve biodiversity by protecting habitats and preventing human activities that could harm plants and animals.
  • Habitat restoration – Restoring damaged or degraded habitats, such as wetlands or forests. This can help to create new homes for plants and animals and increase biodiversity.
  • Invasive species management – Taking steps to control and remove invasive species helps to protect native species and maintain biodiversity.
  • Conservation education – Educating people about the importance of biodiversity and how to protect it. This can help to raise awareness and encourage conservation efforts.
  • Biodiversity offsetting – Involves conserving or enhancing biodiversity in one area to compensate for the loss of biodiversity in another area. This can be used as a tool to help balance the needs of development with the need to protect biodiversity.

You’ve used 10 of your 10 free revision notes for the month

Sign up to get unlimited access to revision notes, quizzes, audio lessons and more

Sign up