Environmental History of the Southwest

Study Guide for Exam #3 (our Final Exam)–Modern Issues

NOTE: The exam will be made up of multiple-choice, true-false, fill-in, and short-answer questions.

Anglo Settlement of the SW

  1. When did the United States make the Gadsden Purchase? When did the railroad connect through the SW?
  2. Describe impacts of livestock grazing on ecosystems of the Southwest.
  3. Define arroyos. How do they form? Where do they typically occur?
  4. Describe impacts of arroyos on the environment.
  5. Explain arguments for and against the notion that early Anglo livestock overgrazing contributed to the late 1800s episode of arroyo cutting in the Southwest.
  6. Explain arguments for and against the notion that climatic variation contributed to the late 1800s episode of arroyo cutting in the Southwest.
  7. Name modern strategies for improved range (livestock) management.

Forest Fire

  1. Discuss the types of evidence used to identify changes in natural fire regimes. How are fire-scarred trees evidence of a surface fire regime?
  2. What is a "fire history graph" and how can it be used to understand fire history?
  3. What trends are evident in total area burned per year in the Southwest since the late 1900s? What factors have contributed to this trend?
  4. Distinguish typical fire frequency and intensity in southwestern ponderosa pine forests before and after the late 1800s-early 1900s.
  5. What is the prominent natural ignition source of fire in the Southwest? Has natural ignition of fire always been a possibility in the Southwest?
  6. How did early historic grazing affect fire regimes?
  7. Contrast surface fires and crown fires. What is the difference between the fuels that create a surface fire and those that create the conditions for crown fire?
  8. What is forest fuel loading and what is its role in fire regimes?
  9. Discuss forest fire management strategies to return wildfire to a more natural role in forests. Give pros and cons.
  10. Wildfire disturbance: Good, bad, or unavoidable phenomenon of environmental life? How can modern society live safely with fire, avoiding its bad aspects while capitalizing on its good side?

Forest Health

  1. What does "forest health" mean?
  2. Are defoliating insects a natural part of forest ecosystems? If so, what about them is different today from the past?
  3. Describe the role of spruce budworm in SW forest fuel loading.
  4. Describe the role of dendrochronology in studying past insect outbreaks.
  5. How do different species of trees serve as a "control group" in the study of insect outbreaks in the tree-ring record? How can outbreaks be distinguished from background climatic variation?
  6. Know the concept of treatment versus control in research.
  7. Contrast spruce budworm outbreaks of the 20th Century versus those prior to 1900.
  8. Is there any association between large recruitments of new trees and climate? How does fire fit in?
  9. Describe multiple lines of evidence of changes in fire occurrence, changes in tree recruitment, and repeat photography of Southwest ponderosa pine forests.
  10. Forest insect disturbance: Good, bad, or unavoidable phenomenon of environmental life? How can modern society live safely with defoliators, avoiding their bad aspects while capitalizing on their good side?

Flooding

  1. Describe Southwestern washes with respect to entrenchment and migrating banks.
  2. Define river discharge.
  3. Define drainage basin. What's another term for drainage basin?
  4. Be familiar with reading a flood hydrograph. Discuss environmental and human factors that influence how flashy or sluggish flooding might be.
  5. Describe the pluses and minuses of bank reinforcement as a strategy to reduce flooding impacts.
  6. What causes Southwestern floods to differ from one another (e.g., seasonal timing, style of storm, etc.)?
  7. Describe recent changes in the occurrence of floods in the Santa Cruz River; don't forget skew.
  8. Distinguish between the mean and median of a distribution. Which of these values is immune to effects of outlying values?
  9. How does dendrochronology apply to studying past flooding?
  10. Flooding disturbance: Good, bad, or unavoidable phenomenon of environmental life? How can modern society live safely with flooding, avoiding its bad aspects while capitalizing on its good side?

Drought

  1. Define drought.
  2. Describe relative importance of precipitation and temperature in deriving drought indices.
  3. Describe drought in terms of duration, magnitude, and spatial extent.
  4. What climatological conditions lead to drought generally?
  5. Identify different types of droughts depending on the affected system.
  6. Put the 1950s SW drought in perspective spatially and temporally.
  7. Put the current SW drought in perspective spatially and temporally.
  8. How are droughts of the past known?
  9. Be able to name droughts in SW history (last 1000 years) that impacted human systems somehow; describe their impacts.
  10. What modern ocean phenomenon seems to associate with occurrence (or not) of multi-year drought in the American Southwest?

Global Change

  1. Know basics of the carbon cycle, i.e., relative magnitudes of pools and fluxes.
  2. Compare today's atmospheric CO2 concentration with that of the pre-industrial past.
  3. Explain and compare two main human contributions to CO2 flux into the atmosphere.
  4. Describe the atmospheric greenhouse effect.
  5. Describe the relationship between atmospheric CO2 and global temperature.
  6. Put the warming of the instrumental record in context of the last 1000 years.
  7. How might vegetation of the Southwest migrate with the climate change projected for the future? Desert and/or mountain ecosystems? How is this possible change known?
  8. What does "ecosystem goods and services" mean? What are some examples?
  9. How do you personally affect the grand carbon equation of life (i.e., which direction)?

Water: Groundwater, Colorado River, and CAP

  1. Describe the hydrologic cycle; don't worry about absolute values, just relative sizes of "pools" and fluxes.
  2. What is significant about the 100th Meridian?
  3. What is an aquifer?
  4. List inflows and outflows for Tucson's groundwater budget.
  5. What are some consequences of overdraft of groundwater?
  6. What is ground subsidence? Why is subsidence a problem? Is subsidence the same as arroyo formation?
  7. Is Tucson in imminent danger of running out of groundwater?
  8. When, what, and where of the Colorado River Compact?
  9. How might the Colorado River compact negotiators have used tree-ring data in their decision making, if only those data had existed at that time?
  10. Describe the Central Arizona Project (CAP). What might southern Arizonans do with their CAP allotment?
  11. In terms of the state-wide water budget, how does Arizona use water?
  12. Evapotranspiration: Good, bad, or unavoidable phenomenon of environmental life?