Warm-Up #41 Complete the Analyzing Data activity on page 158.

Humans in the Biosphere

Objectives Explain how environmental resources are classified. Identify the characteristics of a sustainable environment. Define biodiversity and explain its value. Identify current threats to biodiversity. Describe the goal of conservation biology. Describe two types of global change that are of concern to biologists.

Classifying Resources Environmental goods and services may be classified as either renewable or nonrenewable  Renewable resources can regenerate if they are alive or can be replenished by biochemical cycles if they are nonliving. They are not necessarily unlimited.  Trees, sunlight, wind, water  Nonrenewable resources cannot be replenished by natural processes  Fossil fuels like coal, oil and natural gas (these take millions of years to form from deeply buried organic materials)

Sustainable Development Sustainable development is a way of using natural resources without depleting them and of providing for human needs without causing long-term environmental harm. Takes into account both the functioning of ecosystems and the ways that human economic systems operate. Sustainable strategies must enable people to live comfortably and improve their situation.

Biodiversity Biodiversity is the sum total of the genetically based variety of all organisms in the biosphere.  Ecosystem diversity: includes the variety of habitats, communities, and ecological processes of the living world.  Species diversity: the number of different species in the biosphere.  Genetic diversity: the sum total of all the different forms of genetic information carried by all organisms living on earth today.

Threats to Biodiversity Biodiversity is one of Earth’s greatest natural resources.  Food, industrial products, medicines Human activity can reduce biodiversity by  Altering habitats  Hunting species to extinction  Introducing toxic compounds into food webs  Introducing foreign species to new environments All of these result in loss of biodiversity.

Habitat Alteration The most significant global threat to biodiversity is habitat loss. When land is developed, natural habitats may be destroyed or fragmented. The animals who live in these habitats must learn new behaviors to cope with the changes. Competition increases as resources become limited. Fragmentation results in habitats becoming “biological islands”—The smaller the “island” the fewer species can live there. This results in a loss of biodiversity to the habitat and decreases stability.

Introduced Species Seemingly harmless plants and animals that humans transport around the world either accidentally or intentionally can enter new habitats. They are known as “invasive” or “exotic” species. They can reproduce rapidly since they have no natural predators in the new habitat and drastically alter the balance of an ecosystem. Examples:  Zebra mussels  Leafy Spurge

Conservation The term conservation is used to describe the wise management of natural resources. Strategies include  Manage individual species to prevent extinction  Protecting entire ecosystems to preserve biodiversity. Challenges to conservation are  Economic concerns  Some environmental restrictions can force people to change the way they make their living  Some conservation programs are expensive to implement

Global Change Concerns Ozone Depletion--seasonal decreases in the ozone levels above the polar zones. Each year the “gaps” in the ozone are getting larger and lasting longer. Global Climate Change—Global Temperatures have risen by about 0.6 degrees Celsius since the late 19 th century.  Is it a natural change in the Earth’s climate or a result of increased fossil fuel burning? We don’t know.  If temperatures continue to increase—then what? Sea levels may rise and flood some coastal areas affecting ecosystems and human communities.

Summary How are environmental resources classified?  Give an example of a renewable and a nonrenewable resource What is sustainable development? What is biodiversity? What are some current threats to biodiversity? What is the goal of conservation biology? What are the two types of global change that are of concern to biologists?

Study Guide You do not have to do page 133.

Homework Make sure you have your textbook. We will check them in before the final. Locate your packets for extra credit Continue to work on Final Exam Review Worksheet. Chapter 6 Packets are due on the day of the final.