Biology 100/101
Lecture 2: Ecosystems in Space
Text readings in Life by
Ricki Lewis:
| Testing Your Knowledge:
Chapter 43 (Communities and Ecosystems)
Chapter 44 (Biomes and Aquatic Ecosystems)
| page 864, Questions 1 - 3
Page 884, Questions 1,
and 4
| |
General Biome
Web Resources
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:
populations, biological communities, ecosystems, biomes, and
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
Species: "A group of organisms with similar structural and
functional characteristics which breed only with one another".
Population: A collection of individuals of the same species...
Biological Population: "A group of interbreeding organisms living
in the same area." (Lewis, Life - glossary)
Biological Community: "...a community includes all the
organisms, sometimes hundreds of species, in a given area." (Lewis, Life
- pg. 854)
Terminology: Assemblages of organisms + the environment
Ecosystem:"A unit of interaction among organisms and their surroundings,
including all life in a defined area", (Lewis, Life - glossary)
- Includes all Biotic (living) and abiotic (non-living) factors in the
environment.
Ecosystems may be:
- Large or small, distinct or indistinct
- Nested
Habitat: "the physical and biotic conditions of the places where
individuals live" (Lewis, Life pg. 844)
(WHERE individuals live)
Ecological Niche:"the way that a species exploits resources for
survival, growth, and reproduction"(Lewis, Life pg. 844)
(HOW (and where) individuals "MAKE A LIVING")
Differences in niches among species allow multiple species to
occupy ecosystems
At large spatial scales groups of ecosystems are called Biomes
interacting ecosystems
characterized by a particular type of vegetation (or animal life*) and
largely determined by temperature and rainfall or salinity*
- Spread over large areas
- Not sharply separated
-
*Aquatic: freshwater (e.g., lakes, ponds, rivers) and marine (e.g.,
coastal and oceans).
At the largest scale the biosphere is the global ecosystem - or living shell around the planet
Biomes of
Central and North America Image
What biome does Champaign-Urbana exist in?
The
Tallgrass Prairie
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. 44.2, page
868-870)
Similar types of biomes appear at corresponding latitudes because they
have similar climates, MAINLY TEMPERATURE and PRECIPITATION.
Climate strongly influences the capacity for plants to grow
(productivity). More productive environments mostly support forests.
Why do temperature and precipitation vary?
- Global air circulation and precipitation
- Global Ocean Currents and Climate
- Mountains
and the rain shadow effect
- Local climate patterns affected by proximity to bodies of water
(Great Lakes) and topography (canyons)
Characteristics of some biomes
Tundra
Desert
Grasslands
Temperate Deciduous Forest
Temperate Rain Forests
Tropical Rain Forests
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