@mastersthesis {572,
	title = {The Effect of Prescribed Burning on Southwest Ponderosa Pine Growth},
	volume = {PhD},
	year = {1989},
	school = {University of Arizona},
	abstract = {Study objectives included determining whether prescribed burning affected ponderosa pine growth; mathematically modeling the growth response to burning; and determining whether forest management history affected growth response. I sampled 188 trees from two areas near Flagstaff, Arizona; one area (Brannigan Flat) had been logged and thinned, and the other (Chimney Spring) had not; both were burned in 1976. Within each study area, control and burned plots were of similar age, vigor, height, and competition index. Trees at Chimney Spring were older, less vigorous, and taller, and had a higher competition index than at Brannigan. For each tree, periodic basal area increment (PBAI) was calculated for the years 1974-1984. To determine which variable would best model growth, postfire PBAI (individual years, 1977-1984) was correlated with previous growth (average PBAI 1974-1976); crown ratio; competition index; thinning index; and diameter. Two models of growth response were developed; one oriented toward satisfying theoretical and research goals, and the other, toward management applications. Growth was modeled using stepwise multiple linear regression, and the dependent variable was postfire PBAI. Research Model independent variables were previous growth, years (climate), and treatment-year interaction, and 72\% of total variance was explained. Fire affected growth significantly and negatively for two years, and then burned trees grew similarly to control trees. Management Model independent variables were crown ratio, competition index, crown ratio, subject tree diameter, year, and treatment, and 52\% of total variance was explained. This model, too, indicated a slight negative effect of burning on growth. Management history was not a significant determinant of growth response. Both models validated well; the ratio of observed-to-predicted residual mean square was 1.04 and 0.91 (Research and Management Models, respectively). Thinning index was not significantly related to postfire growth, but a change in carbohydrate allocation from stem wood to crown and root expansion could have resulted in observed burning effects. Management implications include (1) short-term growth decline may result from burning, (2) management history did not affect growth response, and (3) burning impact is greatest in dense stands of small trees.},
	keywords = {Watershed Management},
	url = {http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=746080281\&sid=4\&Fmt=2\&clientId=43922\&RQT=309\&VName=PQD},
	author = {Sutherland, Elaine Kennedy}
}
@mastersthesis {574,
	title = {A Dendrochronological Assessment of Western Spruce Budworm, Choristoneura Occidentalis Freeman, in the Southern Rocky Mountains},
	volume = {PhD},
	year = {1987},
	school = {University of Arizona},
	abstract = {<p>Tree-ring chronologies from ten mixed conifer stands in the Colorado Front Ranges and New Mexico Sangre de Cristo Mountains were used to reconstruct timing, duration, and radial growth impacts of past outbreaks of western spruce budworm, Choristoneura occidentalis Freeman. Graphical and statistical comparisons of tree-ring chronologies from host and non-host tree species, in conjunction with Forest Service records of outbreaks during the twentieth century, revealed that outbreaks were identifiable only in the host chronologies as sharply reduced growth periods. These comparisons also showed that host and non-host tree-ring chronologies were generally similar between outbreaks and that both were responding in a similar manner to climatic variation. A study of defoliation and insect population data that was available for the New Mexico stands demonstrated that host radial growth from 1978 to 1983 was highly correlated with budworm activity. The non-host chronologies from each stand were used to correct the host chronologies for climatic and other non-budworm environmental variations by a differencing procedure. The corrected chronologies were then used to estimate the dates and radial growth effects of past budworm outbreaks. Tree-ring characteristics of twentieth century documented outbreaks were used as criteria for inferring the occurrence of outbreaks in previous centuries. At least nine periods of increased budworm activity were identified in the region from 1700 to 1983. The mean duration of reduced growth periods caused by known and inferred budworm outbreaks was 12.6 years, and the mean interval between initial years of successive outbreaks was 34.9 years. The mean maximum radial growth loss was 50 percent of expected growth, and the mean periodic growth loss was 21.6 percent. There was an unusually long period of reduced budworm activity in the first few decades of the twentieth century, and since that time outbreaks have been markedly more synchronous between stands. Increased synchroneity of outbreaks in the latter half of the twentieth century suggests that areal extent of outbreaks has increased. This phenomenon may be due to changes in the age structure and species composition of forests following harvesting and fire suppression in the late nineteenth and early twentieth centuries.</p>},
	keywords = {Watershed Management},
	url = {http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=753027921\&sid=16\&Fmt=2\&clientId=43922\&RQT=309\&VName=PQD},
	author = {Swetnam, T.}
}
@mastersthesis {594,
	title = {A Neoglacial Pollen Record from Osgood Swamp, California},
	volume = {MS},
	year = {1973},
	school = {University of Arizona},
	abstract = {A core from Osgood Swamp, California, which is located south of Lake Tahoe, in the Sierra Nevada, was analyzed every odd centimeter to depth of 61 cm. The Hypsithermal to Neoglacial transition occurs in the 51 to 49 cm interval. Pinus shows four distinct peaks and troughs, varying more than the other pollen types in the core. The Ericaceae show two distinct peaks accompanying the Pinus lows. Pollen analytical and ecological considerations indicate that bog heaths are the source of the Ericaceous record. The Ericaceae peaks are believed to represent periods of moist coldness corresponding to Neoglacial events in the Sierra Nevada. Correlation of an ash layer at 180 cm, immediately above a radio carbon date of 699 {\textpm} 300 B.P. with an ash layer at 170 cm in my core, and other considerations, give an inferred sedimentation rate of about 47 yr/cm in my core. This places the Ericaceae peaks at about 100 A.D. and 1630 A.D., and the Hypsithermal to Neoglacial transition in Osgood Swamp at about 2400 B.P.},
	author = {Zauderer, Jeffrey Norman}
}
