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Articles 1 - 14 of 14

Full-Text Articles in Physical Sciences and Mathematics

York River Slack Water Data Report : Temperature, Salinity, Dissolved Oxygen, 1971 - 1980, T. J. Brooks Sep 1983

York River Slack Water Data Report : Temperature, Salinity, Dissolved Oxygen, 1971 - 1980, T. J. Brooks

Reports

The slack water survey program, provides an extended series of temperature, salinity, dissolved oxygen and nutrient measurements along the York River. These have been used to:

1) calibrate, verify, and update mathematical models; 2) provide a baseline against which effects of unusual events have been measured; and could be used to: 3) establish annual and longer period "climatological" trends in response to changing natural phenomena and man-made modifications to the estuary; 4) provide a basis against which fluctuations in biota could be compared.

This report contains station locations, survey schedules, field procedures, sample handling procedures, and data reduction and storage ...


The Role Of Four Macrophyte Species In The Removal Of Nitrogen And Phosphorus From Nutrient-Rich Water In A Prairie Marsh, Iowa, Craig B. Davis, Arnold G. Van Der Valk, James L. Baker Jul 1983

The Role Of Four Macrophyte Species In The Removal Of Nitrogen And Phosphorus From Nutrient-Rich Water In A Prairie Marsh, Iowa, Craig B. Davis, Arnold G. Van Der Valk, James L. Baker

Botany Publication and Papers

Precipitation, runoff, and drainage supplied about 1.5 metric tons of NH4-N, 4.1 metric tons of N03-N, and 0.09 metric tons of P04-P to Eagle Lake in 1976. Shoots of Typha glauca, Carex atherodes, Sparganium eurycarpum, and S cirpus validus had ac­ cumulated 18.0 metric tons of N and 1.8 metric tons of P at peak standing crop in late July. During decomposition, shoots of all four species lost organic matter faster than P, and lost P faster than N. Carex, Typha, and Scirpus litter were more effective in retaining or accumulating N and P than ...


Atlas Of Wetlands In The Principal Coal Surface Mining Region Of Western Kentucky, William J. Mitsch, Jan R. Taylor, Kimberly B. Benson, Paul L. Hill Jr. Jul 1983

Atlas Of Wetlands In The Principal Coal Surface Mining Region Of Western Kentucky, William J. Mitsch, Jan R. Taylor, Kimberly B. Benson, Paul L. Hill Jr.

KWRRI Research Reports

This atlas contains maps of wetlands and surface mining activity in the Western Kentucky Coal Field, and focuses on a 3960 km2 (1530 mi2) region where approximately 90 percent of surface mining in the Coal field occures. Some present and potential competition exists between surface coal mining and wetland protection. A wetland classification, based on the recent FWS classification, includes six types of palustrine systems and one each of riverine and laucstrine systems. Wetlands and surface mines are located on twenty-seven 7.5 minute USGS quadrangles that define the study region. A total of 460 km2 (177 ...


The Influence Of Lake Powell On The Suspended Sediment-Phosphorus Dynamics Of The Colorado River Inflow To Lake Mead, T. D. Evans, Larry J. Paulson Jan 1983

The Influence Of Lake Powell On The Suspended Sediment-Phosphorus Dynamics Of The Colorado River Inflow To Lake Mead, T. D. Evans, Larry J. Paulson

Publications (WR)

The Colorado River has been successively modified by the construction of several reservoirs, beginning in 1935 with the formation of Lake Mead by Hoover Dam. These reservoirs are located in a chain, and each one has an influence on the nutrient dynamics and productivity of the river and downstream reservoir. Lake Mead derives 98% of its annual inflow from the Colorado River. Historically, the Colorado River inflow was unregulated into Lake Mead. Regulation occurred in 1963, when Lake Powell was impounded by the construction of Glen Canyon Dam, approximately 450 km upstream. The formation of Lake Powell drastically altered the ...


The Vegetation Of Ledges State Park, Boone County, Iowa, Cindy Lee Johnson-Groh Jan 1983

The Vegetation Of Ledges State Park, Boone County, Iowa, Cindy Lee Johnson-Groh

Retrospective Theses and Dissertations

No abstract provided.


The Effects Of Ultraviolet-B Radiation On Plant Competition In Terrestrial Ecosystems, Warren G. Gold, Martyn M. Caldwell Jan 1983

The Effects Of Ultraviolet-B Radiation On Plant Competition In Terrestrial Ecosystems, Warren G. Gold, Martyn M. Caldwell

Green Canyon Environmental Research Area, Logan Utah

Evidence regarding the interaction of ultraviolet-B radiation and plant competition in terrestrial ecosystems is examined. The competitive interactions of some species pairs were affected even by ambient solar UV-B radiation when compared to control pairs grown without UV-B. Also, the total shoot biomass of these species pairs was depressed under ambient UV-B. Relatively large increases in UV-B radiation altered the competitive interactions of some species pairs grown in pots under field conditions, but did not affect the total shoot biomass production of those pairs. Recent field experiments have examined the competitive interactions of wheat and wild oat under a simulated ...


Effects Of Sewage Pollution In The White River, Arkansas, Arthur V. Brown, Lawrence D. Willis, Peter P. Brussock Jan 1983

Effects Of Sewage Pollution In The White River, Arkansas, Arthur V. Brown, Lawrence D. Willis, Peter P. Brussock

Journal of the Arkansas Academy of Science

Recently there has been much emphasis placed on the importance of leaf detritus processing to the energetics of stream invertebrates. This study was designed primarily to assess the effects of municipal effluent on the ability of a stream community to utilize leaf detritus, and secondarily to evaluate the extent of the pollution of the White River by the Fayetteville, Arkansas, effluent discharge. Physical and chemical water quality and benthos were sampled periodically at one station upstream and two stations downstream from the discharge, and in the Richland Creek tributary. Processing of leaf detritus was also studied at each site using ...


Behavior, Energetics And Management Of Refuging Waterfowl: A Simulation Model , Robert Beneke Frederick Jan 1983

Behavior, Energetics And Management Of Refuging Waterfowl: A Simulation Model , Robert Beneke Frederick

Retrospective Theses and Dissertations

A stochastic simulation model, designed to test the effects of alternative management schemes on refuging waterfowl populations, was constructed from data on fall-migrating snow geese (Chen c. caerulescens) at DeSoto National Wildlife Refuge, Iowa. Components of the model include goose population level, food density and distribution, food-searching flight characteristics, feeding rates, activity and energy budgets, migration rates, and the effects of weather, hunting pressure, and land management practices on the system. Independent data were collected to test model validity. The model validly describes movement from the refuge core to distant feeding areas and provides insight into factors affecting emigration. Refuge ...


Effects Of Fenvalerate, A Synthetic Pyrethroid Insecticide, On Nontarget Organisms In An Old-Field Ecosystem , Richard Seigel Bennett Jan 1983

Effects Of Fenvalerate, A Synthetic Pyrethroid Insecticide, On Nontarget Organisms In An Old-Field Ecosystem , Richard Seigel Bennett

Retrospective Theses and Dissertations

Fenvalerate Pydrin('(REGTM)), cyano(3-phenoxybenzyl)-methyl 4-chloro-(alpha)-(1-methylethyl)benzeneacetate, a synthetic pyrethroid insecticide, was experimentally applied to 3 of 6 1-ha study plots on an old-field site. Two applications of 0.112 kg AI/ha (0.1 lbs/acre) were made during both 1980 and 1981. The effects of fenvalerate on arthropod and small mammal communities, and the degradation and movement of residues are reported;Arthropod populations were monitored with pitfall traps and sweep nets. No significant treatment differences were detected among ground arthropods. Most foliar arthropod populations were significantly reduced (P < 0.05) by fenvalerate, with varying degrees of population recovery, ranging from increases above control levels within 3 weeks by thrips (Thysanoptera) to essentially no recovery by beetle larvae. A few foliar arthropod groups were not reduced, but only springtails (Collembola) significantly increased in number after application;Nine small mammal species were captured in live traps during both years from grids in each plot. In 1980, 16,632 trap nights resulted in 1638 captures of 390 individuals, and in 1981, 14,700 trap nights produced 3911 captures of 787 individuals. Insecticide applications did not significantly affect population size, reproduction, age and sex ratios, or movement patterns for any species;The highest fenvalerate residues were detected on vegetation (12.1 ppm), with little evidence of drift into control plots. Residue concentrations declined exponentially with half-lives ranging from 5.9 to 10.6 days. All insect samples contained < 0.5 ppm fenvalerate. These residues also declined through time. The highest residue levels were found in short-horned grasshoppers ((LESSTHEQ) 0.33 ppm). Residues in ground beetles (Carabidae) were < 0.15 ppm. All mammalian samples contained (LESSTHEQ) 1.0 ppm, with the meadow voles (Microtus pennsylvanicus) containing higher residues than deermice (Peromyscus maniculatus). The low residue levels reflected the low application rate, rapid environmental degradation, and rapid mammalian metabolism of fenvalerate.


Abundance, Distribution, And Diversity Of Buried Seed Populations In The Delta Marsh, Manitoba, Canada , Roger Lynn Pederson Jan 1983

Abundance, Distribution, And Diversity Of Buried Seed Populations In The Delta Marsh, Manitoba, Canada , Roger Lynn Pederson

Retrospective Theses and Dissertations

Several plant communities in the Delta Marsh were analyzed with respect to the distribution, abundance, diversity, and temporal variation in buried seed populations and annual seed rain. Numbers of germinable seeds were measured by placing substrate and seed trap soil samples under two simulated environmental conditions (drawdown and shallow-flooded) in an outdoor shelter;From the seed bank, four times as many seedlings and twice as many species occurred in substrate samples under the drawdown treatment as compared to samples under the shallow-flooded treatment. Many of the common species in the seed bank (Scirpus validus), (Scripus maritimus), Rumex maritimus, Aster brachyactis ...


Water Quality Trends In The Las Vegas Wash Wetlands, F. A. Morris, L. J. Paulson Jan 1983

Water Quality Trends In The Las Vegas Wash Wetlands, F. A. Morris, L. J. Paulson

Publications (WR)

The Las Vegas Wash is a wetlands ecosystem that acts to buffer the effects of wastewater discharges on the receiving waters of Lake Mead. The wash is the terminus for the 4,144 km2 Las Vegas Valley drainage basin, emptying into Las Vegas Bay of Lake Mead (Colorado River). It is in the northern Mojave desert, which receives an average of only 10 cm of rainfall annually. The Las Vegas Wash is technically an artificial wetland supported almost entirely by the perennial flows from sewage treatment plants. These flows contribute an average of 3-7 t of nutrients (nitrogen and phosphorus ...


Use Of Hydroelectric Dams To Control Evaporation And Salinity In The Colorado River System, Larry J. Paulson Jan 1983

Use Of Hydroelectric Dams To Control Evaporation And Salinity In The Colorado River System, Larry J. Paulson

Publications (WR)

The main stem reservoirs on the Colorado River comprise one of the largest and most heavily used freshwater bodies in the nation. These reservoirs (Lake Powell, Lake Mead, Lake Mohave and Lake Havasu) can store up to 53,590,400 acre-feet of water at their maximum capacities. Nonetheless, local water shortages still exist in some areas of the Colorado River Basin. There is also concern that salt concentrations are approaching levels that could severely affect municipal and agricultural uses. Water shortages will become even more acute as demands for water increase with continued urban and agricultural development in the basin ...


Factors Related To Selection Of Fish Scales For Growth Studies Of Yellow Perch, Perca Flavescens , Ahmad Hassan Abdu-Nabi Jan 1983

Factors Related To Selection Of Fish Scales For Growth Studies Of Yellow Perch, Perca Flavescens , Ahmad Hassan Abdu-Nabi

Retrospective Theses and Dissertations

Standardization of the body area for scale sampling for growth studies of fish becomes more essential if the a value in the Fraser-Lee equation is to be standardized as suggested by Carlander (1982). In a study on yellow perch (Perca flavescens) from West Okoboji Lake and Clear Lake in Iowa, the body area located at the tip of the pectoral fin below the lateral line was found to be the best area for scale sampling. This area exhibited the lowest variability in scale size and the lowest frequency of regenerated scales of the 10 areas sampled. The optimum number of ...


Monitoring Defecation Activity Of Infaunal Deposit Feeders, Fred C. Dobbs Jan 1983

Monitoring Defecation Activity Of Infaunal Deposit Feeders, Fred C. Dobbs

OES Faculty Publications

An inexpensive, reliable thermistor device capable of monitoring infaunal foraging activity was built and used in the laboratory to examine effects of temperature on sediment reworking by the maldanld polychaete Clymenella torquata. The worm defecated at least once per hour 55.0 % (12.0 "C) to 88.2 % (5.5 "C) of the time. Defecation rate was linearly and positively related to temperature. Estimated volume of sediment ejected per defecation (0.015 ml) did not change with temperature. Results are compared with previous reworking studies of C. torquata.