Download Unit 11-Ecology

ECOLOGY
CHAPTERS 18-23
Study of the interactions between organisms & the
living & non-living components of their environment.
Today’s Environment

Ecological problems
◦
◦
◦
◦
Exploding human population
Mass Extinction
Thinning ozone layer
Climatic changes
Ecological Research

Conducted using three basic principles:
◦ Observing
◦ Experimenting
◦ Modeling
Energy Flow

Main energy source for life on earth
◦ SUN

Autotrophs
◦ Make food by means of photosynthesis or
chemosynthesis
◦ PRODUCERS

Heterotrophs
◦ Rely on other organisms
for food
◦ CONSUMERS
Types of Heterotrophs
Herbivores: eat plants
 Carnivores: eat animals
 Omnivores: eat both (plants/animals)
 Detritovores: eat dead matter

◦ Ex. Earthworms

Decomposers: break down organic
matter
◦ Ex. Fungi
Food Chains & Food Webs

Food Chain
◦ Shows how living things transfer energy by
eating & being eaten

Food Web
◦ Links all food chains in an ecosystem together
◦ Shows a network of complex interactions
Levels of Organization
Levels of Organization
Description
Biosphere
•Broadest, most inclusive level
•Thin volume of earth & its
atmosphere that supports life
Ecosystem
•Includes all living & non-living
components found in a
particular place
•Pond: fish, turtle, water, etc.
Community
•All interacting organisms
living in an area
•May contain thousands of
species
Population
•All members of a species that
live in one place at one time
Organism
•Simplest level of organization
Ecosystem Recycling

The Water Cycle
Nitrogen Cycle
Carbon Cycle
Biosphere Cycles
Click on diagram to
play a video on
Biosphere Cycles…
Ecology of Organisms

Habitat
◦ Where an organism lives

Biotic Factors
◦ Living components of an environment

Abiotic Factors
◦ Physical & chemical (non-living) characteristics
of an environment
◦ Temperature, light, humidity, pH, salinity, O2
concentration, precipitation, etc
◦ Abiotic factors are not constant
Biomes
Tropical Rain Forest
 Desert
 Tundra
 Taiga
 Grassland
 Savanna
 Temperate Deciduous Forest
 Chapparal

Biomes of the World
Tolerance Curve

Graph of performance vs. values of an
environmental variable, such as temp.
Terms

Acclimation
◦ An organism’s ability to adjust their tolerance to
abiotic factors, such as high elevation

Conformers
◦ Do no regulate internal conditions

Regulators
◦ Use energy to control some internal conditions

Dormancy
◦ State of reduced activity

Migration
◦ Movement to a more favorable environment
Niche
A species’ way of life; the role it plays in
its environment
 Fundamental Niche

◦ Range of conditions a species can potentially
tolerate & range of resources it can
potentially use

Realized Niche
◦ Range of resources a species actually uses
Generalists vs. Specialists

Generalist
◦ Species with a broad niche
◦ Virginia opossum (feeds on anything)

Specialist
◦ Species with narrow niches
◦ Koala bear (eats
only leaves of
eucalyptus tree)
Community Ecology

Symbiosis: Relationships among species
◦ Predation
 Predator kills & consumes prey
◦ Parasitism
 One organism benefits & other is harmed
◦ Competition
 Species compete for same resources
◦ Mutualism
 Cooperative relationship in which both species benefit
◦ Commensalism
 One organism benefits & the other is not affected
Succession

The gradual, sequential regrowth of a species in
an area.
◦ Primary succession
 Development of a community in an area that has not
supported life previously, such as bare rock, sand dunes, or an
island formed from volcanic eruption.
◦ Secondary succession
 Sequential replacement of species that follows disruption of an
existing community.
◦ Pioneer species: species that predominate early in
succession
◦ Climax community: Stable end point following
succession
Environmental Science

A field of science that uses biological
principles to look at the relationships
between humans & the earth.
Human Effects on Environment
Declining ozone
 Greenhouse Effect

◦ CO2 Blanket; increase temperature

Human Population Growth
Effect of Rising Population
Burn more fossil fuels
 Less fresh drinking water
 Decrease in undeveloped land
 Extinction of many species
 Increase in human waste
 Less food
 More disease & death
 Potentially more natural disasters

Taking Action!!
Conservation Biology
 An area of science which
tries to identify &
maintain natural areas
Restoration Biology
 An attempt at saving a
devastated area