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Changes In Populations Of Soil Acari During The First Year After Clearcutting, Sue Ellen Orlaske

Dissertations and Theses

Soil samples taken from a clearcut and adjacent uncut site of a Douglas Fir and Western Hemlock old growth forest in the Cascade Range of southern Washington showed greatly reduced adult and juvenile population densities of macro-phytophagous, microphytophagous, and predatory soil acari in the clearcut. These effects appeared to be due to high lethal summer litter temperatures and reduced pore spaces due to scarification. Also, the number of species of acari in the clearcut was lower than in the control after clearcutting.

Plant Response To The Barstow To Las Vegas Motorcycle Race Of November, 1974, Candace E. Horsley

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine the disturbance spectrum of the perennial plant vegetation by the Barstow to Las Vegas motorcycle race. Transects were taken at the pit area, starting line, and at various locations along the race course. Measurements were also taken in undisturbed control sites near the test areas, the topographic and bio tic features being judged as equal. Methods employed consisted of aerial photograph analysis just before and after the race. On site ground measurements were taken four years after the 1974 motorocycle event. Measurements of diversity, stability, productivity, and community quality were calculated. The …

Studies On The Anatomy Of The Parasitic Gymnosperm Parasitaxus Ustus (Podocarpaceaea), Evelyn Wilkinson

Biological Sciences Theses & Dissertations

An anatomical study of the parasitic gymnosperm Parasitaxus ustus was conducted. Material was collected in New Caledonia, embedded in paraffin or celloidin, sectioned and stained. The apical meristem consists of apical initial cells, central mother cells, the peripheral zone, and rib meristem. Leaves are scale-like, triangular and broadly decurrent at their bases. Resin ducts and prominent sclereids are present in leaves and the cortex of the stem. The parasite-host connection is in the form of a xylem to xylem connection in which the tracheids are connected by bordered pits.

The Effects Of Two Polychlorinated Biphenyls (Aroclor 1016r And Aroclor 1242r) On The Growth And Chlorophyll Production Of Cultures Of Selenastrum Capricornutum, Jude William Grosser

Morehead State Theses and Dissertations

A thesis presented to the faculty of the School of Sciences and Mathematics at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Jude William Grosser on May 11, 1979.

Two Basic Methodological Choices In Wildland Vegetation Inventories: Their Consequences And Implications, Donald Alan Shute

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In designing inventories of wildland vegetation, two of the many basic methodological choices are: 1) whether data are collected, reduced, and stored in discrete classes or as continuous variables, and 2) whether data are gathered as general purpose variables to bear upon many questions, or as specific purpose variables optimized for only one type of prediction. The effects of these two choices on accuracy of vegetation inventories to predict plant community production were examined by comparing regression models built upon differing sets of independent variables "inventoried" from a common data base. Contrary to expectations, discrete variables of classified community types …

Some Effects Of A Grazer, Hyalella Azteca On Ecosystem Level Properties In Aquatic Microcosms, Martin D. Werner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study to determine some ecosystem level effects of an aquatic invertebrate grazer, Hyalella azteca, was performed in aquatic ix microcosms. Impact of the grazer was assessed in three general areas: 1) inorganic nutrient levels of the microcosm water column, 2) productivity and respiration of the biotic community, and 3) plant community composition in the microcosms.

The grazing amphipod caused inorganic phosphorus and nitrogen (except ammonia) levels to be elevated in the microcosms. The increase was due, at least partially, to excretion of nutrients into the water by the amphipod. The presence of H. azteca did not significantly …

The Bryophyte Flora Of Savage Gulf, Grundy County, Tennessee, Yvonne M. Mescall

Masters Theses

Savage Gulf is a broad, deep gorge located on the western edge of the Cumberland Plateau in Grundy County, Tennessee. Prior to this study, no comprehensive lists of the bryophytes of this area existed, and no attempts had been made to describe the bryophyte flora of the gorge or adjacent plateau. The present study was initiated after discovering several-interesting bryophytes on a trip to the gorge in April 1977.

One hundred and eighty-two species of bryophytes from 107 genera in 74 families have been identified for the Savage Gulf area. Of this total, five species are recognized as disjunct Coastal …

The Allelopathic Potential Of Rhododendron Macrophyllum In A Western Cascades Clearcut, Ivan W. Clark

Dissertations and Theses

The purposes of this study were to determine if Rhododendron macrophyllum has the potential to inhibit the growth of other species through the production of water-soluble toxins which are leached out of its litter by rainfall, and to determine if this potential is realized in the field. The study was therefore composed of two part: 1) a series of bioassays to determine the presence an activity of water-soluble phytotoxins in R. macrophyllum leaf litter, and 2) a field study to describe vegetational patterns associated with R. macrophyllum in a western Cascades clearcut.

Root Anatomy Of Fine Species Of Abronia From Southern California And Its Ecological Implications, Jan Webster

Theses Digitization Project

No abstract provided.

The Role Of Allelopathy On The Vegetational Composition Of Disturbed Sites On The Samuel H. Ordway Memorial Prairie, Randy C. Bartels

Electronic Theses and Dissertations

The presence of large numbers of cattle in prairie sites can lead to the trampling and destruction of native vegetation in some areas. These damaged, or disturbed sites are typically invaded by a variety of undesirable alien plant species. Many of the alien plant species possess allopathic mechanisms. These allopathic mechanisms enable the alien species to dominate the disturbed sites, and prevent the re-establishment of native plant species. Attempts are currently underway to preserve remaining tracts of native prairie in South Dakota. The Samuel H. Ordway, Jr. Memorial Prairie in McPherson county is one such tract, and is the research …

Floristics And Phytosociology Of The Pavement Plains In The San Bernardino Mountains, California, Jeanine A. Derby

Theses Digitization Project

No abstract provided.

The Effects Of Selected Pre-Germination Treatments On Six Species Of Summer And Winter Annual Plants Of The East Mojave Desert, James R. Earsom

Theses Digitization Project

No abstract provided.

Leaching Of An Acetanilide Herbicide, Cp55097 In Soil Columns, Regina K. Higgins

Masters Theses

The leachability of the acetanilide herbicide, CP55097 was determined using a soil column system. This herbicide, which is used as a preemergent against certain grasses and broadleaf weeds, was leached through four different soils (sandy clay, sandy loam, sandy clay loam and clay loam) using the following procedure. Plastic columns consisting of 8 rings (2 in. dia. x 1 in.) were assembled and their bottoms covered with cheesecloth. They were then filled with soil and prewetted with water to attain field capacity. Herbicide concentrations equalling 0, 1, 3, 6 lb/A were pipetted onto the soil surface and 0, 1, 2, …

A Taxonomic And Ecological Study Of The Cladonia Species Of The Central Portion Of Fox Ridge State Park In Coles County, Illinois, James L. Jannesse

Masters Theses

Extensive collections were made on the central ridge system at Fox Ridge State Park in Coles County, Illinois. A literature review of the works on the genus Cladonia in North America encompassed major taxonomic collections undertaken in the last 20 years. Also, a historical account on the developments in the Cladonia chlorophaea complex are listed. Basic Cladonia morphology is described, including both microscopic and macroscopic illustrations. The study area was subdivided on a grid system, enabling the collection sites to be numbered. The entire area was covered in two foot intervals. From every entity that was found, ¼ of it …

Translocation Of C14-Labeled Assimilates In Squash Petioles, William John Raupp

Masters Theses

A qualitative analysis of sieve tube sap was undertaken to help determine the method of assimilate movement in phloem. Hydroponically-grown squash plants (Cucurbita melopepo torticollis Bailey) were trimmed to a mature, fully-expanded leaf (the source) and one or more immature, unexpanded leaves (the sinks). The blade of the source leaf was exposed to C¹⁴O₂ in air for 10 minutes and allowed to translocate for 20 or 50 minutes in ambient air. Petioles of treated leaves were cut into sections and ground in cold buffer with a chilled mortar and pestle to extract materials from the translocation stream. …

Biosystematic Studies Of Impatiens Pallida And Impatiens Biflora (Balsaminaceae), Sandra M. Buening

Masters Theses

Impatiens pallida Nutt. and Impatiens biflora Walt. are two closely related species which grow together in mixed populations but do not hybridize. Flower buds of each species were enclosed with glycine bags to prevent insect pollination. These were left isolated until after anthesis to test for self-pollination and self-compatibility. Neither capsule formation nor seed set were observed.

Chromosomal smears showed that each species has a haploid number of ten chromosomes. Polyploidy was not observed.

Field observations of insect pollinators (primarily bees) showed indiscriminate visitation.

Flower buds were again bagged as before. During anthesis, individuals of the two species were cross-pollinated …

Chromosomal Variation Of Claytonia Virginica L. In Illinois, Russell Arthur Hintz

Masters Theses

Thirty-one mass collections of Claytonia virginica were made in eight counties in the eastern half of Illinois. Chromosome counts of pollen mother cells were determined for plants from Richland, Coles, Clark, Douglas, Cook and Moultrie counties. A range of 2n = 8 to 48 was determined with only 4 of the 89 counts being greater than 2n = 30. For all the populations, counts of 2n = 8, 10, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 27, 28, 29, 30, 37, 38, 44, 48 were reported. The two most common counts were 2n = 18 and …