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Unit 3Lesson 6 2 min read

Biodiversity and Conservation Biology

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Learning Objectives

Define biodiversity and its three main levels.
Identify the major threats to biodiversity.
Explain the concept of an ecosystem service.
Describe the goals of conservation biology.

The Variety of Life and Its Preservation

Biodiversity (or biological diversity) is the variety and variability of life on Earth. It is a measure of the health of an ecosystem.

Levels of Biodiversity

1.Genetic Diversity: The total number of genetic characteristics in the genetic makeup of a species. It allows populations to adapt to changing environments.
2.Species Diversity: The number of different species in an ecosystem and the relative abundance of each species.
3.Ecosystem Diversity: The variety of habitats, communities, and ecological processes in the biosphere.

Threats to Biodiversity

Human activities are causing a rapid loss of biodiversity, an event some scientists call the sixth mass extinction.

Habitat Loss and Fragmentation: The single greatest threat. This includes deforestation, urbanization, and the conversion of land for agriculture.
Invasive Species: Non-native species that are introduced to an ecosystem and outcompete or prey on native species.
Overharvesting: Harvesting a renewable resource to the point of diminishing returns. This includes overfishing and poaching.
Pollution: The introduction of harmful materials into the environment, including chemical pollutants, plastics, and excess nutrients (e.g., from fertilizer runoff).
Climate Change: Rapid changes in temperature and weather patterns are altering habitats faster than many species can adapt.

Ecosystem Services

Ecosystem services are the many and varied benefits that humans freely gain from the natural environment and from properly-functioning ecosystems.

Examples: Pollination of crops by insects, purification of air and water by forests and wetlands, decomposition of wastes, and climate regulation.

The loss of biodiversity threatens these essential services.

Conservation Biology

Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It seeks to understand the causes of biodiversity loss and develop methods to prevent it.

Key Terms

Biodiversity
The variety of life in the world or in a particular habitat or ecosystem.
Habitat Loss
The process in which a natural habitat is rendered unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity.
Invasive Species
An organism that is not native to a specific location, and which has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health.
Ecosystem Services
The benefits people obtain from ecosystems. These include provisioning services such as food and water

Check Your Understanding

1

What are the three levels of biodiversity?

2

What is considered the single greatest threat to global biodiversity?

3

Define an 'ecosystem service' and provide one example.