Ecosystems in Space

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

Text readings in Life by Ricki Lewis: Testing Your Knowledge: Thinking Scientifically

Chapter 43 (Communities and Ecosystems
Pgs 853-859, 861-862)
Chapter 44 (Biomes and Aquatic Ecosystems) page 875, Questions 1-3
Page 895, Questions 1 and 4 Page 876, Question 2

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

Today's topic: Organization and integration of life from the individual up to the biosphere

Objectives:

After studying this material you should be able to:

Define and explain the relationships among these concepts: individual organisms, populations, species, biological communities, ecosystems, biomes, and the biosphere.

Give an explanation why many species can coexist in an ecosystem when they are competing for limited resources.

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

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

Key Terms:

population	biological community	ecosystem
biosphere	biome	habitat
abiotic factors	biotic factors	ecological niche

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...

Millions of mites!

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 Natural Resources Canada.

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.

Altitude and temperature from USA Today Weather

Lewis, Life Fig. 44.1, page 879

Seasons and the tilt of the earth

Why Earth Has Seasons from oceansonline.com

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.

Global air circulation and precipitation

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.

Global Ocean Currents and Climate

Current Sea Surface Temperature

Gulf Stream and Climate in N. Europe

What is El Niño?

Local climate is affected by prevailing wind patterns and local topographic features

Mountains and the rain shadow effect

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.

Proximity to bodies of water (Great Lakes - UK and the Gulf Stream)

Lake Effect Snow from USA Today Weather

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