Biology Commons^™

An Investigation Of The Changes Of Species Richness And Distribution Of The Unionidae (Bivalvia: Molusca) Within The Pamunkey Watershed, William Robert Lees

Master's Theses

A survey of the Unionidae within the Pamunkey Watershed was conducted to investigate changes in distribution and species richness compared to a previous survey (Riddick, 1973) conducted over 30 years ago. Species richness decreased from 10 species in the previous survey to four species in the present survey. Notable increases of species richness were found in the upper South Anna and the lower North Anna regions, while sizable decreases were found in the lower South Anna and the upper and middle regions of the Pamunkey River. Regression analyses and t-tests comparing mussel survey data with habitat parameters were conducted to …

The Vascular Flora Of Powhatan County, Virginia, Michael Austin Terry

Master's Theses

The project was undertaken with three main goals in mind: to provide as current and complete an account as possible of the flora of Powhatan County in the form of an annotated checklist; to integrate the information obtained from the inventory into phytogeographical and ecological generalizations currently being developed for the state of Virginia; and, to report any significant or anomalous discoveries. There is no previous county-wide inventory of plant diversity for Powhatan County. However, Corcoran (1981) published a list of plants from the Jones and Mill Creek watershed located in the Fine Creek Mills area of northeastern Powhatan.

Storm-Related Suspended Particulate Matter In Little Westham Creek, John R. Jordan

Master's Theses

Properties of a watershed regulate the amount of suspended particulate matter (SPM) in a stream. The present study examined relationships between storm-related SPM and impervious area and tree cover in the suburban watershed of Little Westham Creek, Richmond, Virginia during Summer and early Fall, 1999. SPM concentration, SPM discharge, and turbidity due to clay, silt and sand, and the areas of impervious surface and tree stand cover in the watershed were measured at three sites. SPM concentration, SPM discharge, and turbidity due to clay were greater upstream than downstream. The percentages of watershed area covered by impervious surfaces and tree …

Transplanting Broodstock Oysters, Crassostrea Virginica, Onto Reconstructed Oyster Reefs To Increase Spat Recruitment In The Piankatank River, Dawn Chentil Sherwood

Master's Theses

Four oyster reefs were recreated from oyster shells to historical proportions in the Piankatank River from 1993-1995. In December 1997, two of the reconstructed reefs were supplemented with large broodstock oysters from Tangier and Pocomoke Sounds. Since total quantity as well as density ofbroodstock were believed to be limiting factors for recruitment in this river, adding stock was expected to raise spat recruitment. Methods included dive surveys on the reefs, and dredge and patent tong surveys on the natural oyster bars. The recruitment of spat to both reefs and bars was significantly higher in 1998 (p<0.001) than in the previous four years and a positive interaction (p<0.005) was seen between the reefs and the year 1998. Based on these dat~ stock enhancement in the Piankatank River successfully improved recruitment and suggest oyster restoration may be facilitated in other areas of the Chesapeake Bay by strategic enhancement of spawning stocks.

Area-Species Curve Applies To Gaps In A Canada Hemlock (Tsuga Canadensis (L.) Carr.) Forest In The Shenandoah National Park, Joseph John Lacroix

Master's Theses

A typical area-species curve shows that species richness (number of species) and island size are positively correlated. I tested whether the area-species concept, which was developed using islands, could be applied to herbaceous plants in canopy gaps in a hemlock community.

I conducted studies in Limberlost, Shenandoah National Park. I measured the species richness of herbaceous plants in six gaps during the summer and fall of 1995 and eight gaps and one non-gap site in the spring of 1996. The two additional gaps in 1996 extended the upper range of gap sizes. I calculated the correlation between species richness and …

Feasibility Of Stocking Grass Carp (Ctenopharyngodon Idella; Cyprinidae) To Control Hydrilla (Hydrilla Verticillata; Hydrocharitaceae) In Lake Anna, Virginia, Paul Matthew Overton

Master's Theses

The goal of this study was to demonstrate the feasibility of using triploid ·Ctenopharvngodon idella (grass carp) to control Hydrilla verticillata in the Waste Heat Treatment Facility (WHTF) in Lake Anna, Virginia. The four objectives were to determine: the frequency of occurrences of grass carp over hydrilla; the proportions of hydrilla to other aquatic macrophytes in the guts of grass carp; effects of physical and chemical factors on movement of grass carp; and a theoretical stocking rate of grass carp for the WHTF. Frequency of occurrence of grass carp over hydrilla was calculated to be 84% and correlated with impoundment …

A Survey Of Cellular Slime Molds At Selected Sites On The James River, Virginia, Nathaniel Lemaster Armistead

Master's Theses

The flood plain of the James River in Virginia supports a variety of deciduous forest associations and has not been examined previously for dictyostelids. This thesis is primarily concerned with the results of a survey of dictyostelids at selected sites in the James River basin. Some incidental observations concerning possible ecological relationships between dictyostelids are included.

Seven of the plant communities of Virginia described by Harvill, Stevens and Ware (1984) afe present in the areas surveyed and collection sites were established accordingly: (1) Mountain Pine-Oak Heath, (2) Pine-Oak Heath, (3) Oak-Hickory Forest, (4) Alluvial Hardwood Forest, (5) Beech-Maple-Tuliptree Forest, (6) …

The Spatial Distribution Of Phytoplankton In Westhampton Lake, Richmond, Virginia, James William Newlin

Master's Theses

The hypothesis is that spatial distributions of phytoplankton standing crop and photosynthetic capacity in Westhampton Lake are homogeneous was tested. Distributions were analyzed with respect to horizontal and vertical planes separately and combined. The study was divided into three time period: 1) late summer stratification, 2) early fall mixing, and 3) fall turnover, based on isothermal lines of the lake at the deepest station. Phytoplankton standing crop was measured by spectrophotometric and fluorometric methods. The photosynthetic capacity was measured flurometrically. Combined horizontal and vertical spatial distribution of standing crop was clumped for the entire lake and during each time period. …

Population Stability Of Three Species Of Zooplankton In Westhampton Lake, Richmond, Virginia, James Christopher Conyers

Master's Theses

Populations of zooplankton, Keratella cochlea's (Rotifera) Bosmina longirostris (Cladocera), and Mesocyclopsedax (Copepoda) were sampled in Westhampton Lake from June 30 to December 22, 1978. Population densities were estimated over time and analyzed for stability relative to the occurrence of rainfall. Two aspects of stability were used for analysis and given operational definitions as follows: Resistance - a population was resistant if its density was not more variable during periods of rain compared with periods of little or no rain; Persistence - a population was persistent if its density during periods of rain was not different from its density in periods …

The Vascular Flora Of The Kersey-Crump Creek Watershed, Hanover County, Virginia, Eddie Reeves Smith

Master's Theses

A floristic survey was conducted in the Kersey-Crump Creek watershed, Hanover County, Virginia from spring 1978 through summer 1980. This upper Coastal Plain area (42 km2) near the fall line yielded 514 species of vascular plants, representing 334 genera and 113 families. Four hundred and seventy-nine county records were established. Panax trifolium, colonizing a rich wooded creek bottom, was the only plant rare to Virginia. Voucher specimens are deposited in the herbaria of the University of Richmond, Virginia, and the College of William and Mary, Williamsburg, Virginia.

The Quality Of Storm Runoff From Different Kinds Of Land Surfaces In The Drainage Basin Of Westhampton Lake, Richmond, Virginia, Margaret Emil Coppedge

Master's Theses

Samples of runoff were collected during storms from four different areas within the drainage basin of Westhampton Lake, Richmond, Virginia, between October, 1977, and January, 1978. The areas were a residential area, concrete street gutter, asphalt parking lot, and broadleaf forest.

The samples were analyzed for pH, levels of reactive phosphate, nitrate, and turbidity, and their effects on the growth of algae from Westhampton Lake.

The pH of runoff from the residential area, gutter, and forest usually ranged between 6-7 and the parking lot usually ranged between 4-5. Levels of turbidity varied considerably between storms and areas. Runoff from the …

Seasonal Nearshore Distributions Of Fishes In A Piedmont Section Of The James River, Virginia, Eugene George Maurakis

Master's Theses

The seasonal nearshore distributions of 17 species of fishes were determined in natural and artificially heated areas in a 9.6 km stretch of the Piedmont section of the James River, Virginia from July, 1973 to June, 1974. Analyses of the seasonal distributions were based on abundance and percent frequency of occurrence data. The maximum abundance and percent occurrence of ten of the 17 species of fishes in natural temperature areas occurred in early autumn. Deviations from this pattern included Notropis analostanus, equally abundant throughout the year, and Lepisosteus osseus, Notropis amoenus, Notropis ardens, Notropis rubellus, Catostomus commersoni and Lepomis macrochirus, …

A Comparative Study Of Fish Populations In The Vicinity Of A Thermal Discharge In The James River, Virginia, Judson Wayne White

Master's Theses

The size, species composition and structure of fish populations in a six mi stretch of the James River in the Piedmont Province of Virginia were analyzed. Twenty collections were made by electrofishing from October 1972 through September 1973 from both the north side of the river, which received a thermal discharge from a power station, and the south side where temperatures were ambient. Parameters investigated were number of species, total number of individuals and the Shannon-Wiener and evenness indices of species diversity. Significant differences in seasonal patterns were found between the communities in the thermal discharge and those on the …

A Survey Of Fresh-Water Oligochaeta And Their Commensal Ciliates From The Richmond, Virginia Area, Elsa Queen Falls

Master's Theses

The distribution of North American aquatic oligochaetes and the ciliates inhabiting their guts have received very limited attention. For this reason, the present study was initiated to survey fresh ­water oligochaetes of the families Aeolosomatidae, Naididae, Opistocystidae, and Lumbriculidae in four bodies of water of the Richmond, Virginia area and to determine the incidence of commensal ciliates within the gut .

The Distribution And Ecology Of The Terrestrial Shell-Bearing Mollusca Of Hanover, Henrico, And Chesterfield Counties, Virginia, John Bayard Burch

Master's Theses

Very little has been published concerning the molluscan fauna of Virginia, this being also true for the area under consideration. A preliminary list of the Mollusca of Hanover County was published by J.B.Burch (1952) in which twenty-five species and subspecies of land snails were reported. Several of the land Mollusca of Henrico and Chesterfield Counties were listed by P.R. Burch (1950). These included the snails Discus patulus Deshayes, Haplotrema concavum (Say), Mesodon thyroidus (Say), Stenotrema hirsutum (Say), Triodopsis Fallax (Say), and Ventridens = (zonitoides) arboreus (Say). Two additional species, Helicodiscus parallelus (Say) and Retinella indentata (Say), were reported by personal …

Gramineae, Vicinity Of Richmond, Virginia, Mary Smith Lynn

Master's Theses

List of grasses documented in the vicinity of RIchmond, Virginia.