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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
941

Early History of Crossdating

Studhalter, R. A. 04 1900 (has links)
No description available.
942

Dendrochronological Studies in New Zealand

Bell, Virginia, Bell, Robert E. 12 1900 (has links)
No description available.
943

Tree-Ring Chronologies in South-Central Alaska

Oswalt, W. H. 12 1900 (has links)
No description available.
944

GROWTH AND YIELD OF EMORY OAK WOODLANDS IN SOUTHEASTERN ARIZONA

Touchan, Ramzi, 1949- January 1986 (has links)
No description available.
945

Cultural and other morphological studies of Perenniporia phloiophila and related species

Flott, James Joseph, 1956- January 1990 (has links)
Perenniporia phloiophila (Aphyllophorales: Polyporaceae) colonizes the bark of live oak (Quercus virginiana Mill.) and is known only in the southeastern United States in this host. Cultural characteristics and mating systems of P. phloiophila and P. medulla-panis, vegetative incompatibility of P. phloiophila and temperature relationships and decay capacities of vegetative isolates of P. phloiophila, P. ohiensis and P. fraxinophila were investigated. Cultural studies indicate macroscopic and microscopic differences between the four species. Antagonistic hyphal interactions developed between different vegetative isolates. Self crosses were compatible. Optimum temperature ranges and maximum growth temperature differed for all species. Mating test results of both species indicate their heterothallic tetrapolar nature. Woods differed significantly in percent weight loss (PWL) caused by each Perenniporia species. No significant difference occurred between different isolates of the same species tested on the same wood. PWL was greatest on oak wood for all fungal species tested.
946

Forest structure and succession over a ten year period in six undisturbed South Florida plant communities

McCollom, Jean Margaret, 1945- January 1990 (has links)
Data were collected on woody vegetation for 10 years in 6 undisturbed plant communities including slash pine forest, wet prairie, hardwood hammock, edge and interior old-growth cypress forests, and freshwater marsh at National Audubon Society's Corkscrew Swamp Sancturary in South Florida. Forested communities all showed a trend toward greater successional maturity. Numbers and total basal areas generally decreased over the 10 year period for early successional species and tropical species affected by the 1982 freeze in hammock and edge cypress communities. Otherwise, total basal areas steadily increased for all species in the forested communities. Initially the slash pine forest contained only canopy pine, but hardwoods entered the sites 3-4 years after fire and continued to increase in number throughout the study. Woody vegetation in the two marsh communities were less stable, partially due to fire. Fire and hydrologic conditions had measureable impacts on community structure and growth patterns.
947

Dendrochronology and fire history in a stand of northern California coast redwood

Brown, Peter Mark, 1956- January 1991 (has links)
Fire-scarred cross-sections from coast redwood (Sequoia sempervirens) at two sites were dendrochronologically dated and used to develop a fire history. Redwood offers a challenge for dendrochronological study due to ring wedging and complacency. Crossdating was successful in 12 of 24 trees. The fire history was developed by comparison of fire scars and fire-associated ring characteristics (resin ducts, double latewood, growth releases, and ring separations) recorded in ring series. Using only dates of fire scars from the first fire in 1714 to the last in 1962, the mean fire interval (MFI) was 9.9 years. MFI for the best represented presettlement segment 1714-1881 was 8.0 years. Using all fire-associated ring features, MFI 1714-1962 was 7.0 years and 1714-1881, 6.0 years. Use of all fire-associated ring characteristics is argued to be a more accurate representation of past fire frequency. MFIs determined are less than others reported for coast redwood and suggest fire frequency in redwood may have been underestimated in past studies.
948

Storage and germination of Quercus emoryi and Quercus arizonica acorns

Nyandiga, Charles Onyango, 1962- January 1991 (has links)
Quercus emoryi Torr. (emory oak) and Quercus arizonica Sarg. (Arizona white oak) are the dominant tree species in many of the oak savannas and woodlands of Arizona and northern Mexico. Objectives of this study were (1) to evaluate germinability on two media as influenced by storage and stratification, and (2) to determine effects of oak canopy and depth of burial on acorn viability and germination. Germination was higher (P < 0.05) on filter paper than in mineral soil in laboratory trials. Maximum germination of Quercus emoryi in the field was observed at 7.5 cm (29%), with only 5% germination at the soil surface. Germination of Quercus arizonica at 7.5 cm (73%) and 15 cm (74%) were not different (P > 0.05) but exceeded germination at the surface (17%). These results are applicable for propagation of the two species in a tree nursery.
949

Baseflow evaluation of a logged small watershed of the Bull Run River, Oregon

Hidayat, Noor, 1952- January 1991 (has links)
The impact of logging operation on baseflow yield on the Bull Run Municipal watershed, Oregon was examined. Daily streamflow data, from 1958 to 1984, for the three small watersheds on the Bull Run river were analyzed. The baseflow recession coefficient was determined by analyses of successive days flows. Least squares and linear regression analysis were utilized to evaluate the effect of treatments. It was shown that logging of 25 percent of total treated watershed reduced mean daily baseflow yield, but this was not significantly different at either the 0.05 or 0.01 level. Also, it was shown by the untreated watershed that there was a significant difference, at the 0.05 level, of baseflow yield between the period of pre- and post-logging. The decreased baseflow yield may have resulted from decreasing fog drip and increasing evaporation rate in the logged areas and from decreasing precipitation on the watersheds during the post-logging period.
950

The behavioral and physiological effects of low-flying aircraft on desert ungulates

Weisenberger, Mara Enyeart, 1966- January 1992 (has links)
I evaluated the effects of simulated noise from low-flying jet aircraft on the behavior and physiology of 6 captive desert mule deer (Odocoileus hemionus crooki) and 5 captive mountain sheep (Ovis canadensis mexicana). I measured heart rate, body temperature, ambient temperature, and behavior related to the number of overflights/day, and decibel levels (dB) animals were exposed to (range = 92-112). I recorded heart rate and body temperatures from transmitters implanted into the body cavity of animals. Ambient temperature was recorded in the pens and behavior was described from visual observations. I compared heart rates during simulated overflights by jet aircraft (N = 112/season) of sheep and deer to data collected prior to and following treatments. I documented differences between heart rates, species, dB levels, and number of overflights/day within and between seasons. All animals became habituated to aircraft noise. Although heart rates increased during overflights, they returned to the resting heart rate in ≤ 2 minutes.

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