Transcript Ecology, Environmental Science and the Big Picture

Ch 1 Ecology,
Environmental Science
and the Big Picture
Night shot of earth…
What is Ecology?
Basic Terminology
• Ecology = study of organisms and
how they interact with each other
and their environment (ecologist)
• Eco from Oikos
• “Oikos”= Greek for “house”
• Ecology = study of the “house” we
live in
What is Ecology?
Basic Terminology
• Relationships/interactions are the
key (feeding, competition, symbiosis,
etc…)
• Environmentalism= concern for how
the natural world is affected by
human activity
• Environment= things that surround
and/or affect an organism
Levels of Life Organization
• Organism = any living thing (characteristics of
life)
• Species = group of organisms that look alike
and can breed to produce viable offspring
• The organism is the fundamental unit of life in
ecology
• Many individuals of the same species living
together in the same area = population
Levels of Life Organization
• Community = all the populations living
together (interacting) in the same area
Levels of Life Organization
• Ecosystem = a biotic community plus the
abiotic factors in its environment
• What is the difference between biotic and
abiotic?
Can it be decomposed further?
Can anything obtain energy from it?
…If no then it is abiotic
Levels of Life Organization
• Biome = a category of related ecosystems
found around the world (rain forest, coral reef)
Levels of Life Organization
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•
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Biosphere = layer of earth containing all life
Extends into atmosphere
Extends down into lithosphere (crust)
Overlaps hydrosphere (all water)
Landscape
• = patchwork of ecosystems that cover a
given area
• More ecologists are shifting focus away from
ecosystems and into landscape in recent years
Habitat vs Niche
• Habitat = physical surroundings
• Niche = Lifestyle
Biomass
• = the total mass of living tissue present in
an area
• More biomass = more stored energy in system
• More sunlight tends to lead to more biomass
5 steps of scientific method
• Observation generates a question
• Question or problem
• Hypothesis = possible answer or explanation,
must be testable, usually
stated as cause & effect
(if…then…)
• Experimentation = test the hypothesis, collect
data (evidence)
• Conclusion/next steps = always 2 items
• is hypothesis supported by the data or not?
What should be investigated next?
Variables in experiments - graphing
Why is water
temp on the yaxis in this
graph?
Variables in experiments
Scientists attempt to keep all conditions in an
experiment constant except 2:
Independent (manipulated) variable: changes are
under the control of the scientist (x-axis on graph)
Dependent (responding) variable: changes occur in
response to changes in the independent variable (yaxis on graph)
Control group – a set of trials are subjects that
experience no changes in the independent variable
Variables in experiments - graphing
Types of Data
1) Categorical (Qualitative) = not involving numbers
A. Nominal Data – categories do not exist in
any particular order
Example: Classifying land-lab plants into families
B. Ordinal Data – categories in which order is
important
Example: Reproductive status categories in deer:
Pre-reproductive (fawns)
Reproductive
Post-reproductive (too old)
Types of Data
1) Numerical (Quantitative) = involving numbers
A. Discrete – only certain values are possible
Example: counting numbers, integers, population size
B. Continuous – any value within a range is
possible
Example: Temperature, Height, etc…
Make sure you do quantifying ecology 1.1 correctly.
Also answer the questions under figure 1.5 on p. 6
Types of Data - Graphing
Histogram (Bar Graph) – use when data are
categorical
• allow bars to touch when data are ordinal
• bars should not touch when data are nominal
Types of Data - Graphing
Scatter Plot – use when data are completely
numerical
• connect the dots to show continuous changes over
time (based on a math function or equation)
• use best fit line or no line to show general trends
or relationships (more common)
Be sure to complete Quantifying Ecology 1.2 on pp. 8-9
Types of Experiments
Lab Experiments
• Much easier to control all
potential variables
• Uses less space
• Results may not be true
to the way nature actually
works
Field Experiments
• More difficult to control all
potential variables
• Requires more space
• Results are much more
true to the way nature
really works