Download Chapter 6 Section 6_3 Biodiversity

Chapter 6: Humans in the Biosphere
6.3 – Biodiversity
Mr. M. Varco
Saint Joseph High School
The Value of Biodiversity
• The total of all the genetically based variation in all organisms in the
biosphere is called biodiversity
• Species Diversity: The number of different species in the biosphere
or particular area
• Most of this diversity exists among
single-celled organisms
The Value of Biodiversity
The Value of Biodiversity
The Value of Biodiversity
The Value of Biodiversity
• Genetic Diversity: refers to the sum total of all different forms of
genetic information carried by a particular species
• Genetic diversity is usually considered to be the most basic kind of
biodiversity
The Value of Biodiversity
The Value of Biodiversity
• Biodiversity is one of earth’s greatest natural resources
• The benefits of biodiversity to society include contributions to:
• Agriculture
• Medicine
• Ecosystem services
Foxglove Plant
The Value of Biodiversity
Threats to Biodiversity
• As human activity reduces genetic diversity, species are put at a
greater risk of extinction
• There are many methods by which humans reduce biodiversity:
• Altering Habitats
• Hunting
• Introducing invasive species
• Release pollution
• Climate change
Threats to Biodiversity
Altering Habitats
•Development often splits ecosystems into pieces, in a process called
habitat fragmentation
•This results in increased species vulnerability
Threats to Biodiversity
Threats to Biodiversity
Hunting:
•Unregulated hunting can cause species to become endangered or extinct
(ex: Passenger Pigeon)
•Endangered species are protected by the Endangered Species Act and
CITES
•Animals in other countries are still at risk due to
difficulty in enforcement of laws
Threats to Biodiversity
Invasive Species
•Organisms introduced to new habitats can become invasive and compete
with native species for limited resources
•Invasive species can drive native species to the point of extinction
Threats to Biodiversity
Giant African Snail
Threats to Biodiversity
South American Pacu
Threats to Biodiversity
Threats to Biodiversity
Pollution
•Acid rain, greenhouse gases, and smog place stress of land and water
organisms
•DDT, for example, prevents birds from laying healthy eggs
Threats to Biodiversity
Climate Change
•Climate change is a major threat to biodiversity, as organisms are adapted
to their environment and have specific tolerances
•Habitat fragmentation results when an organism must move to a new
location or face extinction
Global Average Temperature
Conserving Biodiversity
1. Protecting Individual Species
• The Association for Zoos and Aquariums (AZA) oversee survival
plans to protect endangered species
Conserving Biodiversity
2. Preserving Habitats and Ecosystems
• Governments and conservation groups must collaborate to establish
land as parks and reserves
Conserving Biodiversity
2. Preserving Habitats and Ecosystems
• An ecological hotspot is an area where significant numbers of species
and habitats are in immediate danger of extinction