Download chapter 19 Ecology outline

IE 1
Introduction to Ecology
I. Ecology
*The study of interactions between organisms and the living
and nonliving components of their environment.
*Organisms depend on other organisms and on other nonliving
things in their environment for survival
*collecting info about organisms and their environment then
looking for patterns and seeking to explain these patterns
A. Today’s Environment
*Over the past few decades humans have drastically
changed the environment more than ever before
*In order for the human species to survive, we must learn
how to improve our effect on the environment.
1. The Exploding Human Population
*Most significant environmental change
*Population tripled from 2 billion in 1930 to 6
Billion in 1999 Why????
*Year 2050pop ~7.8-12.5 billion
*More peopleneed more energy, food, and space
For waste…..When will we run out???
2. The Sixth Mass Extinction
*As human pop. UPOther species pop. DOWN
*Hawaiisince 1st colonists 60 of 100 species of
native birds died off…why?...habitat destruction,
overhunting, and introduced diseases and predators
from other environments
*There is evidence of 5 major extinctions…is the 6th
in progress?
3. The Thinning Ozone Layer
*Ozone layer absorbs UV radiation from sun
*CFCs (chlorofluorocarbons) react w/ and destroy
IE 2
ozone.
*Holes in ozonelead to ban on CFCs
*1 percent of UV radiation gets through ozone
…which is responsible for all sunburns and a
half million skin cancers each year
4. Climatic Changes
*CO2 (carbon dioxide) and H2O are transparent to
visible light (it passes through it)
*Greenhouse Effect- natural occurring
phenomenon that insulates Earth from the deep
freeze of space.
*Humans have altered the natural greenhouse effect
by adding more “green house gases” (CO2) into
the atmosphereby burning fossil fuels (coal, oil,
natural gas)increasing CO2 in atm. by 25% in
last 100 years…(Global Warming)
*Ecology is used along w/ other sciences to try to
solve problems like global warming
B. Levels of Organization
*Ecology is divided into 5 different levelseach level
depends on the other
*Ecologists often pick one level to study
*Fig. 19-5
IE 3
1. The Biosphere
*broadest level that includes all organisms on Earth
*All parts of Earth and Earth’s atmosphere that
supports life.
*Only includes the upper 13 miles of crust and 5-6
Miles above crust.
*Most organisms live within a few meters of the
surface
2. Ecosystems
*smaller units within the biosphere
*all living and nonliving things found in a particular
place.
*Ex Pond, Pine forest, prairie…
3. Communities, Populations, and Organisms
a. Community
*all living organisms that interact with each other
within an area or ecosystem
b. Population
*Members of a single species within a community
c. Organism
*Simplest level of organization in ecology
*Study at this level focuses on adaptations by
organisms to be successful in their environment
B. A Key Theme In Ecology
*No organism is isolated all are interconnected
*All organisms depend on the living and nonliving
components of their surroundings
1. Disturbances in Ecosystems
*Any disturbance (change) in an ecosystem spreads
through that ecosystem.
*Ex. Acorn crop effects tick numbers (see fig 19-6)
2. Ecological Models
*Scientists use models to understand the environment
and make predictions about how it might change
*Used to test a hypothesis about an ecosystem
IE 4
II. Ecology of Organisms
*When studying an organism the 1st and most basic question
an ecologist asks themselves is where does it live and
why?
*habitatwhere an organism lives
A. Biotic and Abiotic Factors
*2 major factors influence an organism biotic
factors and abiotic factors
*