Chapter 5: Biodiversity and Conservation Wood

Chapter 5 Outline  Main Idea: Community and ecosystem homeostasis depends on a complex set of interactions among biologically diverse organisms.  Section 1: Biodiversity  Section 2: Threats to Biodiversity  Section 3: Conserving Biodiversity

Section 1: Biodiversity  Key concepts  What is biodiversity? P. 116  Importance of Biodiversity p. 118

What is Biodiversity?  Biodiversity is the variety in life in an area.  The higher amount of biodiversity increases the stability of an ecosystem

Types of Biodiversity  There are 3 main types of biodiversity  1) Genetic Diversity  2) Species Diversity  3) Ecosystem Diversity

Genetic Diversity  The amount of genes, or inheritable characteristics, that are present in a population is the genetic diversity.  These are the differences within a population. These make the population more resilient and stable.

Species diversity  The number of different species and the relative abundance of each species in a biological community is called species diversity.  These are differences between populations. These make the ecosystem more resilient and stable.

Ecosystem Diversity  The variety of ecosystems that are present in the biosphere is known as the ecosystem diversity.  All of the Earth’s ecosystems support a diverse collection of organisms.

Why Protect the Biodiversity?  There are 3 main reasons to protect biodiversity:  1) Economic reasons  2) Aesthetic reasons  3) Scientific reasons

Economic Reasons  Direct economic value- humans depend on plants and animals to provide food, clothing, energy, medicine and shelter.

Economic Reasons cont.  Indirect Economical Value- a healthy biosphere provides many services to humans and other organisms that live on Earth.

Aesthetic Reasons  Aesthetic reasons- increased amount of biodiversity is considered beautiful.

Scientific Reasons  Biodiversity is the source of new medicines, and new studies. Therefore, biodiversity is very important to science.

5.2 Threats to Biodiversity  Key Concepts  Extinction rates p.122  Factors that threaten biodiversity p.123

Main Idea  Some human activities reduce biodiversity in ecosystems, and current evidence suggests that reduced biodiversity might have serious long-term effects on the biosphere.

Extinction Rates  There are two different pathways to extinction:  Background extinction  Mass extinction

Background extinction  Background extinction is the gradual process of a species becoming extinct.

Mass Extinction  An event in which a large percentage of all living species becomes extinct is a mass extinction.

 Species on islands are extremely susceptible to extinction  Islands usually have extremely delicate ecosystems, and altering one link can destroy the entire ecosystem.

Biodiversity

Factors that threaten biodiversity  The current high rate of extinctions is due to a single species… Homo sapiens  Many species no longer have the natural resources they need to survive.  Things like minerals, soil, clean water, clean air and food.

Overexploitation  Overexploitation is the excessive use of species that have economic value.

Habitat loss  2 main forms:  Destruction of habitat  Clearing of a tropical rainforest  Disruption of habitat  A decline in fish populations can dramatically impact a habitat.

Fragmentation of habitats  The separation of an ecosystem into small pieces of land is called habitat fragmentation.

Pollution  Pollution changes the composition of air, soil, and water.  Many of the polluting substances are chemicals that are not found in nature.

Scenario  Solve the following scenario:  Farmers move into a new area of the American West. Their farms are more productive than ever. However, the peregrine falcon’s eggs are too thin to survive. The falcon population immediately plunges. What happened?

Biological Magnification  The increasing amount of toxic substances in organisms as trophic levels increase in food chains, or food webs.

Acid Precipitation  Sulfur and nitrogen compounds react with water and other substances in the air to form sulfuric acid and nitric acid.  Acid precipitation removes calcium, potassium, and other nutrients from the soil, depriving plants of these nutrients.

Eutrophication  Eutrophicaiton destroys underwater habitats for fish and other species.  Occurs when fertilizers, animal waste, sewage or other substances rich in nitrogen.

Introduced Species  Nonnative species that are either intentionally or unintentionally transported to a new habitat are known as introduced species.

5.3 Conserving Biodiversity  Key Concepts  Natural Resources p. 129  Protecting Biodiversity p. 131  Restoring Ecosystems p. 134

Natural Resources  Although there are resources available to provide for six billion people, they are not evenly distributed across the globe.

Renewable vs. Nonrenewable Resources  Renewable resources- they are replaced by natural processes faster than they are consumed.  Nonrenewable resources- they are found in limited amounts, or those that are replaces over very long periods of time.

Sustainable use  Sustainable use means using resources at a rate in which they can replaced or recycled while preserving the long-term environment health of the biosphere.

Protecting Biodiversity  The United States established its first national park -Yellowstone National Park- in  There are also international nature reserves. As of right now, these compose around 7% of the world’s land.

Biodiversity hot spots  At least 1500 species of vascular plants are endemic.  The region must have lost at least 70 percent of its original habitat.  These hot spots originally covered 15.7 percent of Earth’s surface, however, only about a tenth of that habitat remains.

Biological Corridors  These corridors provide safe passage for organisms between different habitat fragments.

Restoring Ecosystems  The larger the affected area, the longer it takes for the biological community to recover.

Bioremediation The use of living organisms, such as prokaryotes, fungi, or plants, to detoxify a polluted area is called bioremediation.

Biological Augmentation  Adding natural predators to a degraded ecosystem is called biological augmentation.