5.3.4: Chapter Summary

Biodiversity exists at multiple levels of organization, including ecosystem diversity, species diversity, and genetic diversity. Biodiversity is negatively correlated with latitude for most taxa, meaning that biodiversity is higher in the tropics.

The core threats to biodiversity are human population growth and unsustainable resource use. These are habitat loss, overexploitation, pollution, invasive species, and climate change. Deforestation is an example of habitat loss. Water and air pollution introduce toxic substances into the environment that harm plants and animals. The collection of plants and fungi at faster rate than they can be replenished is an example of overexploitation. Invasive plant species can outcompete native plants, poison livestock and wildlife, and cause plant diseases. Climate change is causes range shifts and extinctions and disrupts species interactions. Climate change will also raise sea levels, eliminating some islands and reducing the area of all others.

Conservation involves a variety of approaches, and many factors influence the success of conservation efforts. In the United States, the Endangered Species Act protects listed species but is hampered by procedural difficulties and a focus on individual species. International treaties such as CITES regulate the transportation of endangered species across international borders. The non-profit sector is also very active in funding and organizing conservation efforts. Species-level conservation of rare plants can involve propagating and reintroducing rare plant species and restoring their habitat by removing invasive species. Presently, 14.7 percent of Earth’s land surface is protected in some way. Preserves are a major tool in conservation efforts, and large, interconnected preserves favor biodiversity. Ecosystem restoration promotes biodiversity, improves conditions for native species, and reinstate ecosystem services. Through citizen science and botanical gardens, the public can engage directly in conservation efforts.

After completing this chapter, you should be able to...

• Define biodiversity.
• Distinguish among ecosystem, species, and genetic diversity, explaining the value of each.
• Define and provide examples of ecosystem services.
• Distinguish between species richness and species evenness.
• Explain the importance of biodiversity hotspots and identify the characteristics of endemic species.
• Name, define, and provide examples of the five major threats to biodiversity.
• Provide examples of the successes and failures of biological control in regulating invasive species.
• Describe the legislative framework for conservation, providing and describing examples of national and state laws and international agreements.
• Summarize the role of non-profit organizations in conservation.
• Provide specific examples of species-level conservation and discuss the shortcomings of this approach.
• Explain the importance of protected areas.
• Describe principles preserve design.
• Define ecosystem restoration.
• Provide examples of how citizen science and botanical gardens contribute to conservation efforts.

Attributions

Curated and authored by Melissa Ha using the following sources:

• 5 Conservation & Biodiversity from Environmental Biology by Matthew R. Fisher (CC-BY)
• 47.1 The Biodiversity Crisis and 47.3 Threats to Biodiversity from Biology 2e by OpenStax (licensed CC-BY). Access for free at openstax.org.