Environmental Systems
1. What is an environmental system?
A system is a set of interacting components, to change one part of the system would affect
other parts of the system. Earth is an environmental system, so is a lake. (see key points)
2. What are the unique properties of water? In what ways do these properties make life
possible on Earth?
Surface tension, capillary action, high b.p., ability to dissolve many substances
Surface tension – aquatic insects, smooth water droplets
Capillary action – vessels in plants, animals, transport of underground water
High b.p. – allows water to remain liquid on earth
Solvent – allows organisms to store many type of molecules in cells, easy to transport
through the environment (think biogeochemical cycles)
3. What is the difference between power and energy?
Energy is the ability to do work
Power is the rate at which work is done
4. How do potential energy and kinetic energy differ?
Potential energy – stored energy yet to be released
Kinetic energy – energy of motion
5. What is chemical energy?
Potential energy stored in chemical bonds
6. What are the first and second laws of thermodynamics?
1st law – energy is neither created or destroyed (like matter)
2nd law – when energy is transformed, quantity remains the same, but ability to do work
diminishes (i.e. energy is lost as heat) (see key points)
7. Provide an example of how organisms convert energy from one form to another.
Plants take in water and carbon dioxide, combined with sunlight, convert to sugars used for
energy
8. How does energy determine the suitability of an environment for growing food?
The form and amount of energy (ex. At higher latitudes, where there is less sunlight (solar
energy) smaller plants and migrating animals exist) (see key points)
9. What is an open system? What is a closed system?
Open – energy and matter are exchanged across system boundaries
Closed – energy and matter are not exchanged across system boundaries
(see key points)
10. What is a steady state?
A system in which inputs (additions to a system) equal outputs (losses from a system)
 most natural systems are in a steady state (see key points)
11. What are feedback loops? Why are they important?
Feedback is when the results of a process feedback into a system to change the rate of that
process. Feedback can be negative or positive. Most natural systems are negative feedback
loops – system responds to a change by returning to its original state. Negative feedback
resists change and positive feedback amplifies change.
Ecosystem Ecology
1. What is an ecosystem and what are its components?
An ecosystem is a particular location on Earth composed of abiotic and biotic parts (see key
points)
2. How would you know when you left one ecosystem and entered another?
Some ecosystems have very specific boundaries (ex. Cave, lake). Others are more difficult to
distinguish, but perhaps using the area in which a specific organism roams or grows to
indicate boundaries
3. How are ecosystem boundaries imposed by humans sometimes different from natural
boundaries?
National Parks are an example where humans have imposed boundaries (think wolf in
Yellowstone)
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Why is photosynthesis an important process?
Nearly all energy that powers ecosystems comes from the sun, plants harnesses this energy
using photosynthesis and therefore brings solar energy into the system for use by other
organisms (see key points)
What determines the productivity of an ecosystem?
The amount of energy in an ecosystem determines how much life can be supported (refer to
number 8 in Environmental systems)
How efficiently is energy transferred between trophic levels in an ecosystem?
10% rule (see key points)
What are the dominant elements that make up organisms?
C, H, N, O, P
What role does water play in nutrient cycling?
Water is the universal solvent (refer to number 2 in environmental systems) and therefore
many nutrients are soluble in water and can be transported over greater distances
What are the main similarities and differences among the carbon, nitrogen and phosphorous
cycles?
Refer to biogeochemical cycle notes, reading in text, key points
What is the difference between resistance and resilience in an ecosystem?
Resistance – measure of how much a disturbance can affect flows of energy and matter
Resilience – rate at which an ecosystem returns to its original state after a disturbance
(see key points)
What is the intermediate disturbance hypothesis?
The IDH states that ecosystems experiencing intermediate levels of disturbance are more
diverse than those with high or low levels of disturbance
What are the categories of ecosystem services?
There are five: provisions (goods that humans can use directly), regulating services (regulate
environmental conditions, ex. Trees removing CO2), support systems (provide support
services, ex. Pollination of crop plants), resilience (ensures ecosystem will continue to exist,
ex. Several organisms performing the same service but having differing levels of
susceptibility to disturbance), cultural services (cultural or aesthetic benefits, ex. National
parks) (see key points)
How do instrumental and intrinsic values of an ecosystem differ?
Instrumental values of an ecosystem includes ecosystem services; the benefits that humans
obtain from natural ecosystems. Intrinsic values of an ecosystem are benefits independent of
any value to humans. (see key points)
Biomes
1. What characteristics are used to classify terrestrial biomes?
Average annual temperature and precipitation and by plant growth forms (see key points)
2. What are some of the ways that humans use different terrestrial biomes?
Answers can vary – food, shelter, recreation, aesthetic…..
3. What characteristics of a terrestrial biome determine its productivity?
Temperature and rainfall (which in turn determine what can grow and for how long. Refer
to number 8 under environmental systems)