Biology 100/101
Lecture 2: Ecosystems in Space
(Print Version)

Announcements &
Assignments

Lecture Objectives

Terminology:
Assemblages of organisms

Terminology:
Assemblages of organisms
& the environment

Biome Location

Characteristics
of Biomes

Lecture Syllabus

IB 100/101 Home Page

Announcements

Answers to many of these questions can be found on the Text On-Line Learning Center. Select "Student Edition" from the left hand menu, select the text chapter you want, and finally, select either "Testing Your Knowledge" or "Thinking Scientifically". Links to answers can be found on these pages.

You may also ask questions and see answers to your classmates' questions in Web Crossing in the "Talk to Jim, Ross, and Ed" discussion.

The content of today's lecture will help you answer question #1 on this assignment:

Take-home Assignment #1, Ecosystems, Biomes, and Succession Due At Lecture Tuesday February 7

Objectives:

After studying this material you should be able to:

1. Define and explain the relationships among these concepts: individual organisms, populations, species, biological communities, ecosystems, biomes, and the biosphere.
2. Give an explanation why many species can coexist in an ecosystem when they are competing for limited resources.
3. Explain why different regions of the globe have different climates, and consequently support different biomes. Describe and explain the effect the following have on the climate (rainfall and temperature) of an area:

latitude

altitude

tilt of the axis of the earth

global air circulation patterns

global ocean currents

proximity to bodies of water

mountain ranges

4. Describe the characteristics of the following major terrestrial biomes: tundra, desert, prairie (grassland), temperate deciduous forest, temperate rain forest, tropical rain forest.

Key Terms:

Terminology: Assemblages of organisms

Individual: One organism - could be one human being, one corn plant, one bacterial cell.

Population: "A group of interbreeding organisms living in the same area." (Lewis, Life - glossary)

Species: "A group of organisms with similar structural and functional characteristics which breed only with one another" - could consist of several populations.

Biological Community: "...a community includes all the organisms, sometimes hundreds of species, in a given area." (Lewis, Life - pg. 855)

• Champaign-Urbana, your room, even your roommate, all harbor biological communities...
• Eyelash Creatures
• Body Creepy Crawlies from PBS' Nova Series
• Body Beasts: No man is an island. He is an ecosystem. National Geographic, Dec. 1998
• Q & A concerning Head Lice from National Geographic

Terminology: Assemblages of organisms + the environment

Ecosystem:"All organisms and their nonliving environment in a defined area", (Lewis, Life - glossary)

A definition that includes the concept of dynamic interactions in an ecosystem from BiologyOnline.org.

• Includes all biotic (living) and abiotic (non-living) factors in the environment.

• Ecosystems may be:

• Large or small - we could think of a small pool or the entire earth as ecosystems.
• distinct or indistinct - ecosystems sometimes blend one into another so the boundaries are not distinct.
• Nested - small, separate ecosystems can be nested within a larger ecosystem, like a pond ecosystem located in a forest ecosystem.

Habitat: "the physical place where an organism lives" (Lewis, Life - glossary)

Niche: "all resources a species uses for survival, growth, or reproduction" (Lewis, Life - glossary)

• HOW (and where) individuals "MAKE A LIVING" in their habitat
• Differences in niches among species allow multiple species to occupy the same habitat.
• Niches - Lewis, Life Fig. 43.4, page 857

Biome: "one of several major types of terrestrial ecosystems" (Lewis, Life - glossary)

• At large spatial scales, groups of interacting ecosystems are called Biomes, characterized by a particular type of vegetation and largely determined by temperature and rainfall.
• Spread over large areas
• Not sharply delineated - vegetation types tend to blend into another where temperature and rainfall change.
• You probably know the major types of biomes already - deserts, grasslands, tundra, rainforests, etc.

Biosphere "the ecosystem of the entire planet" (Lewis, Life - glossary)

• At the largest scale the biosphere is the living shell around the planet

In what biome is Champaign-Urbana located?

• Biomes of Central and North America Image
• Tallgrass Prairie Photo
• Prior to settlement, more than 60% of Illinois, approximately 22 million acres, were covered with prairie. Today, just over 2,000 acres remain, less than one-hundredth of one percent. Tall grass prairies are endangered ecosystems in Illinois.
• Types of grasslands in NA

Why are biomes located where they are?

Lewis, Life Fig. 44.4, page 881

The location of different biomes is determined by local climatic conditions, mainly average annual TEMPERATURE and PRECIPITATION.

These two factors strongly influence the types of plants that can survive in the area.

Why do temperature and precipitation vary?

• Latitude and temperature from Encyclopedia of the Atmospheric Environment
• The concepts to understand are these:

The Earth is a sphere

The sun's rays are more directly overhead and deliver more intense energy per unit area near the equator.

The further away from the equator (north or south), the lower in the sky the sun appears and the same amount of solar energy is spread over a larger surface area.

• Seasons and the tilt of the earth
• Earth Rotation and Revolution from physicalgeography.net
• Northern hemisphere winter solstice animation from physicalgeography.net
• Northern hemisphere summer solstice animation from physicalgeography.net

• Try the 5 question Survey to see if you really do understand this concept. (from learner.org, Annenberg/CPB)
• Lewis, Life Fig. 44.2, page 880
• Seasons on Mars?
• The concepts to understand are these:

The intensity of sunlight varies with the angle of the sun's rays.

The angle of the sun's rays varies over the course of a year because the axis of the Earth is tilted 23.5 degrees.

• Lecture Activity
• Global air circulation and precipitation
• Altitude and temperature from USA Today Weather
• Lewis, Life Fig. 44.1, page 879
• Lewis, Life Fig. 44.3, page 880
• Location of deserts on earth
• The concepts to understand are these:

Rising, warm, moist air expands and cools at higher altitudes, causing the moisture in the air to condense and form rain clouds.

Falling air is compressed and heated at lower altitudes, increasing it's ability to hold moisture and dry the surface of the land.

• Mountains and the rain shadow effect
• Local climate is affected by prevailing wind patterns and local topographic features
• Rain Shadow in the NW U.S. Prevailing winds W -> E
• Rain shadow in South America Prevailing winds E -> W
• The concepts to understand are these:

Rising, warm, moist air expands and cools at higher altitudes, causing the moisture in the air to condense and form rain clouds.

Falling air is compressed and heated at lower altitudes, increasing it's ability to hold moisture and dry the surface of the land.

• Global Ocean Currents and Climate
• Current Sea Surface Temperature
• Gulf Stream and Climate in N. Europe
• What is El Niño? from UIUC WW2010 Project
• Lake Effect Snow from USA Today Weather
• The concepts to understand are these:

Water temperature changes more slowly than land surface temperatures.

The temperature of large bodies of water affects the air temperature.

Characteristics of some biomes

We will not "cover" specific biome characteristics in lecture, but use your text to learn the basics and follow these links if you are interested in learning more about a particular biome.

Tundra

• Photo: Lewis, Life Fig. 44.13, page 888
• Missouri Botanical Garden's Virtual Tundra
• Some tundra facts
• Biological community & adaptations
• Tundra plants
• Tundra animals

Desert

• Photo: Lewis, Life Fig. 44.8, page 884
• Cold vs. hot deserts
• Deserts of North America
• The Ultimate Desert Resource
• Missouri Botanical Garden's Virtual Desert
• Biological community & adaptations
• Desert plants
• Desert animals

Grasslands

• Photo: Lewis, Life Fig. 44.10, page 885
• Savannah photo
• Types of grasslands in NA
• The Tallgrass Prairie in Illinois
• Ken Robertson's Prairie Page
• Missouri Botanical Garden's Virtual Grasslands
• Biological community & adaptations
• Grassland plants
• Grassland animals

Temperate Deciduous Forest

• Photo: Lewis, Life Fig. 44.11, page 886
• Missouri Botanical Garden's Virtual Temperate Forests
• Biological community & adaptations
• Temperate deciduous forest animals

Temperate Rain Forests

• Big tree!
• The Coastal Temperate Rain Forests of North America

Tropical Rain Forests

• Photo: Lewis, Life Fig. 44.5, page 882
• Rainforest Action Network
• Rainforests From Missouri Botanical Garden
• Biological community & adaptations
• Rain forest plants
• Rain forest animals