Plant Biology Commons^™

The Effect Of Dwarf Mistletoe (Arceuthobium Americanum) Upon A Portion Of The Carbon Budget Of Lodgepole Pine (Pinus Contorta), Nancy Ellen Broshot

Dissertations and Theses

Arceuthobium americanum is a vascular plant which is parasitic upon Pinus contorta var. murrayana. Its documented effects include reductions in host growth, vigor and wood quality. The specific physiological changes that occur in the host are, for the most part, unknown.

In an attempt to understand the manner in which the mistletoe alters its host's carbon budget, a model is proposed which states that the host plant has priorities for carbon allocation. The model proposes that the parasite will access the host's carbon initially in terms of carbon intended for storage, next, in terms of carbon intended for growth, …

Variation In Leaf Macronutrients Of Overstory Trees As Influenced By Species Season And Soil Type In The Great Dismal Swamp Of Virginia, Bruce J. Bandle

Biological Sciences Theses & Dissertations

Leaf macronutrient variation was studied in four plant communities in the Dismal Swamp of Virginia. composition differed markedly between these sites. Soils and species Eight important overstory trees were studied in August 1980; whereas red maple (Acer rubrum L.} and black gum (Nyssa sylvatica Marsh.}, which occurred on all four sites, were sampled seasonally. Significant differences (p .05) were found in the nutrient concentrations of the leaves between species, seasons, and sites. These differences may be attributed to inherent species characteristics, leaf expansion, nutrient translocation, and differences in soil organic matter content, pH, and degree of …

Rare Vascular Plants Of Maine : A Critical Areas Program Report, Susan C. Gawler, L. M. Eastman

Maine Collection

Rare Vascular Plants of Maine : A Critical Areas Program Report

Based on Rare Vascular Maine Plants (1978) with Additional Herbarium Data and Rare Plants Information by L.M. Eastman.

Introduction, Criteria, Annotated Rare Plant List, Species Accounts, Additional Herbarium Data, County & Town Index Editing by Susan C. Gawler.

Executive Department, State Planning Office, 189 State Street, Augusta, Maine, 04333 (June 1981).

Contents: Acknowledgements / List of Tables / List of Figures / Part One: Introduction / Part Two: List of the Rare Vascular Plants of Maine / Part Three: Species Accounts / Part Four: Subspecific Taxa / Appendices / …

Cover Of Plants With Extrafloral Nectaries At Four Northern California Sites, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Percent cover of plants with extrafloral nectaries was investigated in three California habitats with the same physiognomy as habitats previously studied in Nebraska (perennial native grassland, riparian forest, deciduous forest). In contrast to Nebraska where cover of plants with extrafloral nectaries reached 14 percent, no plants with extrafloral nectaries were found in any California transect. Chaparral was also studied; no plants with extrafloral nectaries were found.

The Flora And Sandhills Prairie Communities Of Arapaho Prairie, Arthur County, Nebraska, Kathleen H. Keeler, A. T. Harrison, L.S. Vescio

School of Biological Sciences: Faculty Publications

The Arapaho Prairie is a 526-hectare (two-section) tract of upland Sandhills prairie located approximately nine miles southwest of the town of Arthur in Arthur Co., Nebraska (Sec. 31, 32 T18N R39W). The Prairie is at the extreme southwest edge of the 52,000-km² Nebraska Sandhills (see Kaul 1975) and is floristically and ecologically typical of the slightly drier, western part of this vegetation type. Sandhills prairie which stretches across much of north central Nebraska is a unique type of "mixed" grassland (Pool 1914, Rydberg 1931, Tolstead 1942, Weaver 1965) created by impact of the dry, continental climate on the extensive …

Arapaho Prairie, Arthur County, Nebraska: Approximate Ap Grid For Gis, Kathleen H. Keeler, A. T. Harrison, L. S. Vescio

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Grid map of field sites at Arapaho Prairie in Arthur County, Nebraska. Scale 1 5/16" = 1/4 mile. Shows permanently marked vegetation quadrats, blowouts and ravine washouts, roads, and 100' contour intervals. Part of the map was destroyed by mice. What remains of the map as of 2013 is shown.

Morphology And Distribution Of Petiolar Nectaries In Ipomoea (Convolvulaceae), Kathleen H. Keeler, Robert B. Kaul

School of Biological Sciences: Faculty Publications

The distribution of petiolar nectaries in 24 species of Ipomoea was investigated. Petiolar nectaries were found on 12 species (8 new reports, 4 confirmations of previous reports) and quoted from the literature as being found on 3 other species; they were absent from 9 species investigated. The structure of petiolar nectaries in the genus ranges from simple beds of superficial nectar-secreting trichomes (1 species), to slightly recessed "basin nectaries" (8 species), to "crypt nectaries," which are structurally the most complex extrafloral nectaries known (3 species). (Structures were not determined for 3 species.) Petiolar nectaries are present in all subgenera, but …

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.

Plant Distribution And Succession Within Interdunal Depressions On A Virginia Barrier Dune System, Robert Wayne Tyndall

Biological Sciences Theses & Dissertations

A unique series of interdunal depressions was recognized on the barrier dune system of southeastern Virginia. Plant distribution and succession, and environmental factors controlling them, were studied in the series. Plant community distribution appears to be predominantly controlled by soil moisture, interspecific competition, and feral hog disturbance. Both biotic and physiographic succession are apparent with Quercus virginiana probably climax for both. Salt spray and feral hog and migratory waterfowl activity are important controlling factors of plant succession. Results indicate that the zonal appearance of shrubs and trees on the Virginia and North Carolina coasts is due to the absence of …

Beach Vegetation And Oceanic Processes Study Of Popham State Park Beach, Reid State Park Beach, And Small Pt. Beach, Philip Trudeau, Paul J. Godfrey, Barry S. Timson

Maine Collection

Beach Vegetation and Oceanic Processes Study of Popham State Park Beach, Reid State Park Beach, and Small Pt. Beach

by Philip Trudeau, Paul J. Godfrey and Barry S. Timson

"Prepared Under Cooperative Agreement Between the Maine Department of Conservation and the Soil Conservation Service, United States Department of Agriculture, September 1977."

On Cover: Time and Tide Resource Conservation and Development Project.

Contents: List of Figures / List of Tables / Introduction / Plant Community Research / Oceanic Processes / Historic Analysis of Barrier Beach Movement and Erosion / Dune Dynamics / Suggestions for Long Term Management / Appendices A - …

Biosystematics Of The Abronia Villosa Complex From Southern California, Ned R. Curtis

Theses Digitization Project

No abstract provided.

Structural Comparisons Of Four Plant Communities In The Great Dismal Swamp, Claire Virginia Dabel

Biological Sciences Theses & Dissertations

Four plant communities in the Great Dismal Swamp, located on the coastal plain in southeastern Virginia, were sampled and estimates of density, basal area and aboveground standing crop biomass were determined, Biomass was estimated as 229,800 kg/ha in the Chamaecyparis thyoides community and as 344,500 kg/ha in the Taxodium distichum community. Biomass for the two hardwood communities, the

Acer-Nyssa community and mixed hardwood (Quercus-Nyssa-Acer-Liriodendron-Liquidamber) community was estimated as 195,700 kg/ha and 194,600 kg/ha respectively and did not differ significantly (P

Anatomical Observations On Floating Leaves, Robert B. Kaul

School of Biological Sciences: Faculty Publications

An examination of 24 genera of aquatic plants having floating leaves and leaf-like thalli has been made. Functional stomata occur on the adaxial sides of floating leaves of angiosperms and some ferns, and in some floating leaves there are stomata on the abaxial surface as well. Most floating leaves have prominently chambered mesophyll, and in some instances the chambers are locally enlarged and form buoys.

Aquatic Plant Communities Of Vermilion County, Illinois, John A. Wiedman

Masters Theses

No abstract provided.

Ipomoea Carnea Jacq. (Convolvulaceae) In Costa Rica, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

This is the first report of Ipomoea carnea (Convolvulaceae) from lowland Costa Rica. These populations are unusual for the species in flower color, flowering season and pollinator. Other aspects of the biology of the species in Guanacaste, especially pollination, flower robbing and extrafloral nectary visitors, are discussed.

A Comparison Of Two Artificial Substrates In The Determination Of Net Primary Production, Leland C. Faulconer

All Master's Theses

This study was to determine if a significant difference exists between two types of artificial substrates used to measure the growth rate of periphyton in a warm spring. Chlorophyll was used as an indirect measure of biomass in comparing the substrates and estimating net primary production. A semi-quantitative algal survey was done for each of the sites sampled.

The study was carried out for one year and it was demonstrated that there was a statistically significant difference between the two substrates.

Mutual Exclusion Between Salmonberry And Douglas-Fir In The Coast Range Of Oregon, Kenneth Ray Still

Dissertations and Theses

One serious problem faced by the forest industry in the Pacific Northwest is poor regeneration of commercial trees on land which is harvested and subsequently dominated by brush species. In Coastal Oregon, salmonberry is one of these brush species. Detailed investigations of field sites indicate that light intensity in the brush stands was low but sufficient for germination and early growth of Douglas-fir seedlings and soil moisture percentages and nutrient levels were high enough to support early Douglas-fir growth. Laboratory tests demonstrated the presence of leachable phytotoxins in the leaves of salmonberry. The hypothesis resulting from this study is that …

Plant Succession In The Great Dismal Swamp Of Virginia, Susan Woodward Walker

Biological Sciences Theses & Dissertations

Vegetational composition and environmental parameters were analyzed. for 14 stands. Cluster diagrams based on index of similarity values illustrated interstand relationships. The Index of Fluctuation was developed for the analysis of intrastand dynamics. Based on the densities and numbers of species of trees and saplings within a stand, it indicated degree of compositional stability. It was concluded that present vegetation is divided into relatively distinct communities which have resulted, at least in part, from disturbance.

Annual Pasture And Weed Plant Ecology, B J. Quinlivan

Journal of the Department of Agriculture, Western Australia, Series 4

The purpose of this article is to outline a few basic principles of pasture and weed ecology with particular reference to seed dormancy mechanisms.

These principles apply to many pasture plants and weeds, although their relative importance varies with the particular plants under study.

Old Field Succession In Pinellas County, Florida, Roger T. Poole

Masters Theses

No abstract provided.

Dormancy And Life Span Of Saffron Thistle Seeds, B J. Quinlivan, J. R. Pierce

Journal of the Department of Agriculture, Western Australia, Series 4

RESEARCH in the Geraldton area has indicated that seeds of the saffron thistle (Carthamus lanatus) spread their germination over some seven years but most germinate in the first two years.

Factors influencing the rate of germination and the survival of seeds are the depth of burial and the presence of termites in the soil.

Microorganisms And Soil Structure, T. M. Mccalla

Department of Agronomy and Horticulture: Faculty Publications

SUMMARY

Laboratory tests were made to determine the effectiveness of different compounds and microbial groups in increasing the stability of Peorian loess lumps against the action of falling water drops. The influence of these on percolation tests in the laboratory was also determined.

Many organic substances-dextrose, sucrose, starch, peptone, cullulose, and gum arabic-did not themselves contribute directly to soil-structure stability, though these substances do furnish energy material for soil microorganisms, which can convert them readily into either microbial tissue or decomposition products that increase soil-structure stability. Lignin, proteins, oils, fats, waxes, resin, and paraffin increased the stability of lumps of …