Sunset

Graduate Take Home Exam

  1. Vegetation management decisions used to be based on biological criteria (back in the "good old days"). Within the last few decades, they have been based largely on economic criteria. More recently, vegetation management decisions have been based on social and political criteria. We seem to be moving away from management based on biology and ecology, at least on federally managed lands. Vegetation managers are essentially applied ecologists; they are not political or social scientists. Can they remain true to their education as applied ecologists and still contribute to decision-making in today's society? How? Please be specific. [300 words or fewer; 10 points]

  2. This course attempts to reach seniors and graduate students, and graduate students are expected to complete additional work in exchange for graduate credit. However, it is difficult to reach both audiences simultaneously. We have been largely dissatisfied with our numerous and varied attempts to offer a meaningful graduate experience in this course. Thus, we seek your input on how to do so, within the constraints of a 4-credit course (i.e., completely separate class meetings for the two target audiences is unacceptable). How can we elevate RAM 546 to a level that is meaningful for graduate students? This question is not a gift; please take it seriously. [No limit; 10 points]

  3. You have been hired by Saguaro NP to develop a general management strategy for dealing with current and future plant invasions. Describe the elements of your recommended strategy. You are to focus on all the plant invasion problems, so the management strategy must be general in nature. In your answer, please address the current efforts employed by Saguaro NP to deal with plant invasions and evaluate these within the context of your recommended strategy. [600 words or fewer, 30 points]

In-Class Exam

  1. List 3 objectives underlying the use of recent clearcuts by the Forest Service on Mt. Lemmon. [6 points]

  2. Quantitatively describe differences in the height of aspen at 7800' and 9000' at sites we visited on Mt. Lemmon. [3 points]

  3. Describe the phenology of stem growth for conifers characterized by "fixed" growth. [3 points]

  4. List 4 specific strategies the Apache-Sitgreaves National Forest is using to mitigate or minimize the effects of the 1996 Cottonwood fire. [4 points]

  5. The Lakeside Ranger District of the Apache-Sitgreaves National Forest has determined that several plant communities are too common, and others are too rare. Specifically, they would like to increase Vegetative Structural States (VSS) 2A, 3A, 4A, and 5A at the expense of VSS 1, 4C, and 5C. Briefly describe the physiognomy of the desired states, and describe several specific strategies that are being used to facilitate the transformation of states. [10 points]

  6. World-wide, what is the human population growth rate? Describe the implications of this growth rate for vegetation management at two different scales--landscape and local. [9 points]

  7. BHP Copper in San Manuel has recently implemented a vegetation rehabilitation project known as IMPACT that ____________. [3 points]

    1. will eliminate salt cedar from riparian areas
    2. uses livestock to revegetate mine tailings
    3. will restrict off road vehicle use in riparian areas
    4. restores abandoned crop land
    5. none of the above

  8. Abandoned crop fields along the San Pedro River on BHP Copper lands return naturally to _____________. [3 points]

    1. desert scrub and herbaceous weeds
    2. mesquite bosque
    3. salt cedar
    4. any of the above

  9. Spreading of municipal sewage sludge (biosolids) to accelerate revegetation on mine tailings at BHP Copper in San Manuel is an economically feasible alternative to ______________. [3 points]

    1. planting of Eucalyptus
    2. spreading horse manure
    3. growing alfalfa
    4. capping with top soil
    5. none of the above

  10. Fire policy at Saguaro National Park has been adjusted for sites ______________; at these sites, all fires are classified as "wildfires." [3 points]

    1. near the park boundary
    2. on calcareous soils
    3. below 8000 feet elevation
    4. invaded by yellow star thistle
    5. below 5000 feet elevation

  11. Herbicides are only infrequently used to control non-native plants in Saguaro NP because ________________. [3 points]

    1. of the cumbersome bureaucratic red tape
    2. they don't work
    3. resource managers are opposed to their use
    4. they are too expensive
    5. it's too windy

  12. The following non-native plant(s) have been found in Saguaro National Park. Circle all that apply. [3 points]

    1. salt cedar
    2. fountain grass
    3. red brome
    4. Bermuda grass
    5. buffel grass
    6. Lehmann lovegrass

  13. C3 photosynthetic pathway plants generally have a competitive advantage over C4 plants under which of the following environmental conditions. Circle all that apply. [3 points]

    1. high temperatures typical of Tucson summers
    2. low atmospheric CO2 concentrations typical of the "pre-industrial" period
    3. high atmospheric CO2 concentrations that are expected in the next century
    4. moist summers around Tucson during the monsoon
    5. moist springs around Tucson during a strong El Niño

  14. It is difficult to predict future human land use practices across the Earth's surface because this component of global change responds heavily to ___________. [3 points]

    1. socioeconomic forces
    2. atmospheric CO2 concentrations
    3. sea level
    4. Bill Gates
    5. atmospheric methane concentrations

  15. Ecosystem stability has two components. Circle the two components from the list below. [3 points]

    1. reassurance
    2. resilience
    3. rectification
    4. resistance
    5. redemption
    6. rehabilitation

  16. According to a 1993 report by the Office of Technology Assessment, the cost of clearing zebra mussels from intake pipes associated with industrial and municipal water-works in the US will reach _______________ over a 10-year period. [3 points]

    1. $31,000
    2. $310,000
    3. $3,100,000
    4. $31,000,000
    5. $310,000,000
    6. $3,100,000,000

  17. Describe one example of how different aspects of global change might interact to determine future vegetation structure or function. [6 points]

  18. Provide an example of how basic scientific understanding of vegetation has fostered a specific vegetation management strategy. [6 points]

  19. Many non-native plant invasions in preserves and parks consist of several large primary populations and many peripheral satellite populations. Describe a general strategy for controlling the continued spread of this type of invasion. [6 points]

  20. Explain the "grass/fire cycle" as it presumably relates to invasion of non-native grasses into the Sonoran Desert. [10 points]

  21. Biological invasion represents an important aspect of global change that has many ecological and economic impacts. Most importantly, biological invasions are exacerbating the biodiversity crisis. Explain the rationale behind this statement. [7 points]