Conserving Biodiversity (College Board AP® Environmental Science) : Study Guide

Domestication of organisms

What is domestication?

• Domestication is the process of taming wild species and adapting them for human use, including agriculture, work, and companionship

• Domesticated species are often genetically distinct from their wild counterparts due to selective breeding

Examples of domesticated organisms

Domestic livestock

• Cattle, pigs, and chickens have been bred for traits like fast growth, high yield, and docility

• Selective breeding has reduced genetic diversity, making these populations more vulnerable to diseases

Honeybees

• Honeybees (Apis mellifera) are managed for honey production and pollination services

• Domesticated colonies often lack the genetic diversity of wild populations, making them more susceptible to pests and diseases like Varroa mites

Crop plants

• Species like corn, wheat, and rice have been bred for higher yields and pest resistance

• This has led to the loss of wild relatives and genetic diversity

Impacts of domestication on biodiversity

Genetic erosion

• Focusing on a narrow range of high-yield breeds or strains reduces the genetic pool

  • Example: Bananas cultivated globally are mostly of the Cavendish variety, making them highly vulnerable to disease outbreaks like Panama disease

Displacement of wild species

• Expansion of agricultural land for domestic species often leads to habitat loss for wild species

  • Example: Soybean and palm oil plantations replacing tropical forests

Increased disease risk

• Monocultures and large, uniform populations can lead to rapid spread of diseases

  • Example: Foot-and-mouth disease outbreaks in livestock due to high-density farming

Mitigating the loss of biodiversity

Why is mitigating biodiversity loss important?

• Biodiversity

  • supports ecosystem services like pollination, water purification, and climate regulation

  • increases ecosystem resilience to disturbances and environmental changes

• Mitigation efforts focus on:

  • protecting species and their habitats

  • reducing human impacts

Key strategies to mitigate biodiversity loss

Creating protected areas

• Establishing national parks, wildlife reserves, and marine protected areas to conserve habitats

  • Example: Yellowstone National Park protects a range of species and ecosystems from development and exploitation

Use of habitat corridors

• Connecting isolated habitats with wildlife corridors or bridges allows species to migrate safely and maintain genetic diversity

  • Example: Wildlife overpasses in Canada help species cross highways without risk

Promoting sustainable land use practices

• Agroforestry, crop rotation, and reduced pesticide use minimize environmental impacts

  • Example: Shade-grown coffee plantations help preserve tropical forest habitats

Restoring degraded habitats

• Reforestation, wetland restoration, and invasive species removal help recover biodiversity

  • Example: Mangrove restoration projects in Southeast Asia protect coastal biodiversity and prevent erosion

Legislation and international agreements

• Laws like the U.S. Endangered Species Act (ESA) and international treaties like CITES regulate trade and protect species

• Environmental Impact Assessments (EIAs) help prevent projects that could harm biodiversity