Second Exam, Spring 1997

Define the following: (3 points each)
- phytomer
- tiller
- day neutral plant
- short shoot
- interception loss
True or False (circle T or F) (3 points each)
- T F Adventitious buds are often the source of resprouting shoots following canopy disturbance in shrubs.
- T F Apical meristems give rise to secondary growth in woody plants.
- T F Most conifers exhibit decurrent growth habit.
Name three principle types of meristems in a grass plant and explain the relationship between meristem type and rate of regrowth following herbivory. (8 points)
Explain how shoot morphology could be used to predict the susceptibility of shrubs to systemic herbicidal treatments. (8 points)
Dan Robinett described a disturbance threshold that controls hydrological processes on semi-desert grassland sites near Arivaca. Explain this grazing threshold response (what critical factor is being altered) and the resultant hydrological and vegetation changes that take place when the threshold is exceeded. (8 points)
Seed cone production is a critical aspect of wildlife management in forest ecosystems. Describe general approaches for maintaining consistent cone production in multi-species assembledges. Be sure your answer addresses cone production on both small and large spatial scales and over short and long time frames. (8 points)
Rena Ann Abolt and Sheridan Stone echoed our earlier lectures when they indicated that appropriate vegetation management is dependent on objectives for a particular site. What is the primary objective at Fort Huachuca Military Reservation? List 3 additional objectives for specific sites at Fort Huachuca. (6 points)
- Primary objective:
- Other objectives:
Circle the most appropriate response from the group of italicized terms. (3 points each)
- The simple, linear model of vegetation dynamics proposed by Clements, Gleason, Westoby et al. has been replaced by a model proposed by Clements, Gleason, Westoby et al.
- This latter model is commonly known as succession model, organismic view, individualistic model, state-and-transition model, succession.
Select a species of plant or animal, and briefly describe the habitat in which it is typically found. Would you characterize this species as early-, mid-, or late-successional in this habitat? Why? (8 points)
Describe specific steps you would use to maximize the abundance of the species you listed in the previous question. Assume you are operating within a 40-hectare plant community surrounded by relatively undisturbed vegetation. Identify at least 3 factors that constrain your ability to manage for this species on this site. (8 points)
Foresters used to regard early-successional angiosperms such as alder and black locust to as "weeds" that competed with desirable species. What attributes of these species have contributed to a change in foresters' perceptions of them? (6 points)
Livestock grazing apparently contributed to a reduction of "pristine" vegetation in southern Arizona. However, livestock grazing is being used to restore tropical dry forest in Guanacaste National Park (Costa Rica). Is grazing good or evil, from the standpoint of environmental degradation? Explain. (7 points)
Graduate:
Explain why one cannot easily extend concepts of nutrient limitation in crop systems to natural ecosystems (Chapin et al. paper). (25 points)
Graduate:
The Tillamook fire, on the west side of the Cascades, converted a large conifer forest to a community dominated by sprouting angiosperms. The latter community persists on the site today, more than 60 years later. Discuss how this apparently "stable" (climax?) conifer forest could be converted to another "stable" (climax?) community with this disturbance. It may be useful to consider the type, intensity, frequency, and scale of disturbance, and successional status at the time of disturbance in your answer. (25 points)