This study was conducted to investigate the effects of four drip irrigation treatments on five fruiting characteristics of cotton (Gossypium hirsutum L.) using periodic observations to gauge the relative impact of these effects over time. The fruiting characteristics measured were: (1) number of flowers, (2) percent boll set, (3) number of bolls, (4) weight boll-1, and (5) seedcotton production. The irrigation treatments included four levels that in total season applied irrigation equaled 60, 68, 76, and 83 cm of water. Periodic observations included three, 3-week-intervals from the onset of flowering (26 June) to cutout (29 August). Results indicate that irrigation treatments had a significant effect on all characters measured, only in the later stages of development (later in the season) with higher amounts of irrigation applied producing higher levels of each character measured. Significant differences were found among periods of observation for all characters measured.

The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that has received relatively little attention is the interaction between groundwater and surface waters at locations where interflow zones are intersected by the surface waters. The objective of my research is to investigate how CRBG interflow zone exposures in Mosier Creek may be controlling groundwater elevations in the area. The methods used include: (1) geochemical analysis of well cuttings and detailed geologic mapping along area streams to identify interflow zones of individual CRBG flows, (2) analysis of stream discharge data and groundwater elevation data to confirm exchange of groundwater and surface waters, and (3) collection and analyses of 31 water samples from area wells, streams, and springs, to determine if waters from individual CRBG aquifers can be hydrochemically identified and to further constrain understanding of surface and groundwater interactions. My study confirms that the general elevation of the Pomona Member and Basalt of Lolo interflow zone creek exposure is coincident with the elevation where a change in slope of the decline trend in 2004 is seen in Mosier area well hydrographs. Furthermore, the results of stream discharge data indicated a close connection between drawdown from groundwater pumping during irrigation season and groundwater- surface water interaction. At the time of drawdown in the upper-most CRBG aquifer (Pomona), the stream transitions from gaining to losing water into the groundwater system. Elemental chemistry data indicates the Frenchman Springs Sentinel Gap aquifer waters are the most evolved waters in this study. Stable isotopic data reinforced this determination as the Sentinel Gap waters are the lightest, or most negative, with regard to δD and δ18O. Sentinel Gap samples were more depleted than other aquifer samples by 4.38 to 6.89 0/100 for δD and 0.39 to 0.59 0/100 for δ18O. The results of the general chemistry and isotope data reveal a more evolved chemical signature in lower watershed groundwater versus a less evolved signature for waters from wells located higher up on the Columbia Hills anticline. This was interpreted to be the result of the major structural features in the area providing for a more regional pathway of recharge in lower watershed groundwaters, versus a more local source of recharge for upper watershed groundwaters. There was also a pronounced commingled signature in the elemental ratios of lower watershed aquifer waters. The suspected mechanism of recharge to lower watershed wells is through younger Cascadian deposits upslope from the local watershed. The findings of this study reveal the importance of a detailed understanding of CRBG stratigraphy and its relation to surface waters, especially for other areas within the Yakima Fold Belt or Oregon and Washington. Studies that do not consider the influence that individual CRBG flows can have on groundwater-surface water interactions, and the groundwater system as a whole, run the risk of improperly assessing the groundwater resource for a region.

Redband trout density was examined in three forested streams in central Oregon at two scales, pool channel unit and microhabitat. Two streams were in roadless areas and one was in a "highly managed" watershed. At the larger spatial scale, trout displayed a seasonal shift in habitat use from early to late summer. There was a positive correlation between trout density and pool structural complexity during summer base flow. The association was intensified throughout the summer as stream flow continued to drop. The structural complexity of each pool was quantified using an index integrating structural variability and depth. Twenty-two pools were divided into microhabitats, or pool subunits with similar characteristics using a qualitative classification scheme describing different structural elements comprising the pool habitat. Microhabitat was partitioned between fry and older trout throughout the summer: Fry generally used stream margins, backwaters, and shallow areas; whereas, trout one year and older used deep areas (depth greater that 0.5 m) and cover associated with substrate and wood. The use of cover by trout one year and older doubled from June to August. This change in use was coupled with the increased association with structural complexity at the channel unit scale. The large substrate and wood that provided cover also increased the structural complexity of the pool. As trout increased their use of cover, their densities increased in more complex pools. Man-made log weir pools in a simplified stream were evaluated for their structural complexity and compared to the shallow natural pools in the same reach. Log weir pools had greater average depth, but were less complex than natural pools, and could maintain a similar density of trout. The structural complexity in natural pools appears to compensate for their shallow depth. Log weir pools enhanced with placement of a rootwad supported higher densities of trout. Addition of a rootwad provided microhabitats associated with cover that were lacking in weir pools without other structures added. When using instream construction to create pool habitat, complex structure that provides microhabitats associated with cover is more effective at holding higher densities of fish under late summer low flow conditions. / Graduation date: 1996

Population size of Clavibacter michiganensis subsp. sepedonicus in potato cv Russet Burbank and plant response as affected by drought were assessed in a greenhouse experiment. Water deficit stress and no stress treatments, and inoculum densities of 0 or 2 X 10��� cfu C. m. sepedonicus/seed piece were arranged factorially. Stem populations of C. m. sepedonicus were significantly lower in the water deficit stress treatment compared to the non-stressed treatment at every sampling date in both experiments. In seven of the eight harvests the number of C. m. sepedonicus cells/g of stem tissue for the water deficit stress treated, infected plants was a factor of 10 lower than the non-stressed treatment. Foliar symptoms of bacterial ring rot were not observed, but symptoms developed in tubers. Compared to the noninoculated control inoculum reduced aerial biomass from 12 to 21% and tuber yield from 15 to 38% in samples taken four times after the drought was terminated. Reduction of these same variables due to water deficit stress ranged from 17 to 21% and 15 to 41%, respectively, compared to the non-stressed control. Therefore, both water deficit stress and C. m. sepedonicus had similar effects on growth and tuber yield of potato. / Graduation date: 1995

Habitats for juvenile chinook salmon (Oncorhynchus tshawytscha) were observed at a high flow during the spring of 1989 and at a low flow during the spring of 1991 in the lower American River of California. Parameters of microhabitats in eight macrohabitats were measured. Mean column water velocity and total water depth variables were used to statistically compare juvenile chinook salmon microhabitat distributions between and among macrohabitat type/reach and flow combinations. Using mean column water velocity and total water depth as independent variables, each macrohabitat type/reach appeared to be unique. Mean column water velocity seemed to be a better descriptor of juvenile chinook salmon habitat selection than was total water depth. Riffles appeared to be the preferred macrohabitats for large non-schooling chinook salmon at both flow levels. Root wads, woody debris, and submerged terrestrial vegetation were utilized extensively and provided a significant cover for schooling chinook salmon during the high flow period. Habitat utilization by chinook salmon appears to be influenced by nonhydraulic variables. Application of models in current instream flow studies need to include factors such as water temperature and aquatic insect production. / Graduation date: 1993

No description available.

Darbe analizuojama Dusios ežero ties Meteliais vandens lygiai. Darbe buvo naudojami dviejų laikotarpių paros vandens lygių duomenys: 1945 – 1970 ir 1972 – 1999 metų, nes 1971 metais buvo įrengtas šliuzas reguliatorius. Vandens režimo pokyčiams palyginti naudotos DHRAM programinės įrangos 32 vandens lygių charakteristikos, kurių pagalba nustatyta, kokią įtaką padarė šliuzo reguliatoriaus įrengimas. Atlikus statistinę analizę nustatyta, kad 32 charakteristikos pagal vidutines vandens lygių reikšmes didžioji dalis yra padidėjusios, o pagal variacijos koeficiento reikšmes daugiausia yra sumažėjusios charakteristikos. Šliuzo reguliatoriaus įrengimo įtaka Dusios ežero hidrologiniam režimui maža ir jis didelės įtakos neturėjo. / The paper analyzes water levels in Dusia at Meteliai. The paper analyses two periods of daily water level dynamics under pre-impoundment (1945 – 1970) and after impoundment (1972 – 1999) conditions. The comparison of changes in water levels included DHRAM software 32 characteristics, which provided assistance to the impact made sluice regulator installation. Statistical analysis has shown, that the 32 characteristics of the average values of water levels in most of the increase, while the coefficient of variation of values mainly decrease in performance. Sluice controller installation influences the hydrological regime of lake Dusia small and he did not have a significant impact.

Maternal colonies of the big brown bat, Eptesicus fuscus were studied in Delaware and Grant Counties from 21 May to 22 September, 1992. Nineteen colonies of bats were located and revisited several times during the summer. Bats were captured, sexed, aged, weighed and banded at each site. The weight gain pattern of the bats was related to rainfall and temperature during the summer. Other factors that might affect weight gain such as ectoparasites, tooth wear, and wing damage were also measured.The summer of 1992 had below normal rainfall in May and above normal rainfall in June and July. Temperatures were below normal during the study period. The weights of captured bats were compared to weights of bats captured at similar colonies during the same period in 1988, a dry year, and 1989 a wet year. Both of these years had near normal temperatures. Lower weight gain for juveniles and for adult females in late spring and early summer of 1992 was associated with higher than average precipitation and lower than average temperatures during the period. / Department of Biology

Spatial distribution of species and thus the composition of deciduous forests are expected to change in response to global climatic warming. Climate-growth response algorithms in forest simulation models that represent the influence of climate on tree growth are based on the geographic range limits of a species. These models assume that temperature limitations control the latitudinal range boundaries for tree species in the eastern United States, and that water limitations control the western range boundary. This study investigated spatial variation of tree-growth responses to historical variations in climate using tree-ring data for Quercus rubra L. from 71 study sites across latitudinal and longitudinal temperature and precipitation gradients in eastern North America. Correlation analyses were used to identify significant site-specific associations between radial growth indices and 130 climate variables for the common time interval 1930-1980. Geographic information systems (GIS), and Mantel and partial Mantel spatial correlation analyses were used to map, identify, and measure spatial associations between oak sensitivity to climate and regional climate patterns to test the hypothesis that climate controls the spatial distributions of species range limits.Seasonal climate variables exhibited the strongest correlations with radial growth most consistently across the 71 study sites. However, spatial patterns in regional climate were only weakly associated with spatial variation in red oak sensitivity to climate variables. Contrary to expectations, correlations between red oak radial growth indices and temperature variables at northern and southern sites were not significant, failing to support the hypothesis that latitudinal range limits are defined by temperature effects on mature tree growth. High early growing season temperature reduced growth mostly at sites in the southwest region, which concomitantly experienced high inter-annual variability in soil moisture. Increased early growing season site water balance and precipitation was associated with greater radial growth in the western third of red oak's range, partially supporting the hypothesis that the western range limit is defined by limited water availability. These results indicate that climate only partially determines range limit locations; thus model projections may exaggerate forest responses to climate change. / Department of Biology

Bibliography: leaves 105-121. / viii, 133, [28] leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis tests the hypothesis that plant strategies to respond to seasonal flooding can be used to predict their tolerance to variation in water regime. The studies illustrate contrasting strategies for survival in seasonally fluctuation water levels. These are tested in the field against similar species. Plants are surveyed at four stages of flooding at Bool Lagoon. The morphologically plastic species, V. reniformis and Triglochin procerum, respond to flooding with taller shoots and increased investment in photosynthetic tissue. It is concluded that the reproductive effort is much lower in the field than in the pond experiments, and changes in the population density of both species are not related to water regime. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1997?