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


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Lecture Objectives

Terminology:
Assemblages of organisms

Terminology:
Assemblages of organisms
& the environment

Biome Location

Characteristics
of Biomes

Lecture Syllabus

IB 100/101 Home Page


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Text readings in Biology: Concepts and Investigations, 1st edition, by Marielle Hoefnagels

Chapter 40 (Communities and Ecosystems
Pgs 804-809)

Chapter 41 (Biomes
Pgs 824-833)

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Objectives:

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

Note that exam questions and written assignments will be based on the learner objectives included in this lecture outline. Not all the questions provided at the chapter ends in the text or on the text web pages may be appropriate study aids. Use those that reflect the lecture 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:

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: "Members of the same species occupying a region." (Hoefnagels, Biology Concepts and Investigations - glossary)

Biological Species: "A population or group of populations, whose members can interbreed and produce fertile offspring" (Hoefnagels, Biology Concepts and Investigations - glossary)

Biological Community: "A group of interacting populations that occupy the same region" (Hoefnagels, Biology Concepts and Investigations - glossary)


Terminology: Assemblages of organisms + the environment

Ecosystem: "A community and its nonliving environment" (Hoefnagels, Biology Concepts and Investigations - glossary)

  • 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" (Hoefnagels, BiologyConcepts and Investigations - glossary)

Niche: "all resources a species uses for survival, growth, or reproduction" (Hoefnagels, Biology Concepts and Investigations - glossary)

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?


Why are biomes located where they are?

Earth's Major Terrestrial Biomes (Hoefnagels, Biology Concepts and Investigations Fig. 41.5, page 829)

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?