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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Methane and carbon dioxide fluxes in created riparian wetlands in the midwestern USA effects of hydrologic pulses, emergent vegetation and hydric soils /

Altor, Anne E., January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 134-146).
12

Hydromorphic characteristics of soils formed in the Lawrence Swamp-Hop Brook basin of Amherst, Massachusetts /

Gorden, David Scott 01 January 1994 (has links) (PDF)
No description available.
13

Loblolly pine response to drainage and fertilization of hydric soils

Andrews, Lisa M. 16 December 2009 (has links)
Loblolly pine (<i>Pinus taeda</i>) productivity on wet flats of the lower coastal plain of Virginia is largely affected by the presence of high water tables and infertile soil. Site preparation by bedding and ditching can alleviate high water tables and increase aerated soil rooting volume, enhancing pine productivity. Fertilizing and liming may improve soil fertility by increasing available nutrients and soil pH. The purpose of this study was to evaluate two widely used site preparation methods, bedding and ditching, and to study the effects of fertilizer added at plantation age 9 years. Three site preparation treatments, on jurisdictional wetlands near Franklin, VA, were evaluated for their effects on water table depths and rotation-aged loblolly pine growth and yield. The study consisted of three blocks of three 4-ha plots each; all blocks had been harvested and chopped and burned in 1969. The treatments were none (control), bedded and ditched. In 1978, fertilizer treatments were applied to four-O.l0 ha subplots in the center of the 4-ha plots. Treatments were none (control); P; N and P; and N, P, and lime. Water table levels were measured biweekly during the growing season and monthly, thereafter, for the first three years and at age 23 years. A 12.5-percent inventory of overstory diameters with a subsample of total heights was completed for all species on each plot. / Master of Science
14

The influence of hydrology and time on productivity and soil development of created and restored wetlands

Anderson, Christopher John, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 153-166).
15

Vernal Pool Mapping and Geomorphology in the Appalachian Mountains of Pennsylvania

Blackman, Taylor Nathaniel 11 June 2019 (has links)
Vernal pools are small seasonally-ponded wetlands that provide crucial habitat for amphibian reproduction and support trophic levels beyond their boundaries. The Ridge and Valley physiographic province in Pennsylvania is known to have vernal pools, but a regional inventory and geomorphology assessment is needed. My research is split into two independent parts focusing on the higher elevation areas of this region to determine vernal pool distribution and characteristics. Vernal pools were mapped using a LiDAR based suitability model and leaf-off aerial imagery interpretation. Four terrain rasters derived from a 1-meter DEM (modified wind modified wind exposure, terrain surface convexity, topographic position index, and a multiresolution index of valley bottom flatness) were used in the suitability model. An analysis of variance (ANOVA) and Tukey's HSD test found a significant difference using the model between terrestrial (non-wetland) habitat and vernal pools. Photo interpretation and field surveying lead to an inventory of 1011 vernal pools. Geomorphology was assessed from 13 variables to determine the best for vernal pool prediction. Three variables were significant for the occurrence and frequency of vernal pools; saddles with higher surface area, 0.6 to 1.5 kilometers between the summits of parallel ridgelines, and the presence of periglacial related solifluction. Vernal pool distribution is greater than previously known and they occur in predictable settings. Further research should focus on how and where vernal pools form, their impact on water quality, role in forest ecology, and ways to legally protect them at the state level. / Master of Science / Vernal pools are seasonally-ponded wetlands that are very important for amphibian reproduction. The Appalachian Mountains of Pennsylvania are known to have vernal pools, but comprehensive inventory is lacking. My research consists of two parts that focus on the higher elevation areas and assess the distribution and qualities of the vernal pools. Vernal pools were mapped using a LiDAR based suitability model and leaf-off aerial imagery interpretation. Statistical analysis was completed to prove that there was a significant difference in terrain morphology between non-wetland habitat and vernal pools. This research resulted in a total inventory of 1011 vernal pools. Results found that vernal pools were likely occur in landscape positions with higher surface area, 0.6 to 1.5 kilometers between the summits of parallel ridgelines, and the presence of topographic features indicative of glacial processes. Vernal pools are much more abundant than previously known and they occur in predictable settings. Further research could focus on the formation of vernal pools, impact on water quality, role in forest ecology, and ways to legally protect them at the state level.
16

The influence of hydrology and time on productivity and soil development of created and restored wetlands

Anderson, Christopher John 02 December 2005 (has links)
No description available.
17

Atributos químicos e textura do solo em veredas conservadas e antropizadas no bioma Cerrado / Chemical attributes and texture of the soil in conserved and altered wetlands (veredas) in Cerrado biome

SOUSA, Ricardo Fernandes de 15 July 2009 (has links)
Made available in DSpace on 2014-07-29T16:24:21Z (GMT). No. of bitstreams: 1 RICARDO FERNANDES.pdf: 1993075 bytes, checksum: 9fd3eb6ccef6337fadda8d38b2a10ec3 (MD5) Previous issue date: 2009-07-15 / The objective of this work was to study the soil of wetlands situated in conserved and altered environments (in agricultural and cattle areas), by determining the chemical attributes and texture of the soil. The study was carried through in the central region of Cerrado biome, in the state of Goiás, in wetlands situated in the City of Bela Vista de Goiás. There have been selected three wetlands for soil sampling: one conserved wetland, surrounded by natural vegetation (cerrado); one altered area, with occurrence of pasture in its adjacent areas; and another wetland, also altered, with the occurrence of agriculture in its adjacent areas. The samplings were taken in the months of April and May of 2008, through the use of lines of reference, according to their positions in the relief, in upper, average and lower position, following approximately the direction of the line of draining of the wetland. It has been collected samples in three depths: 0-10 cm; 10-20 cm and 20-40 cm. The variables studied have been: texture, pH in CaCl2 0.01 M; micronutrients (Cu, Fe, Mn, Zn and B), macronutrients (P, K, Ca, Mg and S), concentration of Al and potential acidity (H+Al), and soil organic matter content (SOM). It was verified that the clay percentages in the lower region of the relief are higher in altered environments and the percentage of silt are higher in the wetland adjacent to the agricultural area. In lower position of the relief, the concentrations of SOM are lesser in wetlands adjacent to the agricultural areas and pastures. In the conserved wetland the base saturation is higher in lower position of relief and, in this same position, the acidity (pH) and the aluminum concentration is lesser than that in the average and upper positions, occurring the inverse in farming landscapes. / Este trabalho objetivou estudar os solos de áreas úmidas (veredas) situadas em ambientes conservados e antropizados (em áreas agrícolas e de pecuária), por meio da determinação de atributos químicos e textura do solo. O estudo foi realizado na região nuclear do bioma Cerrado, no estado de Goiás, em veredas situadas no município de Bela Vista de Goiás. Foram selecionadas três veredas para amostragem de solo, sendo: uma vereda conservada, circundada por vegetação natural (cerrado); uma área antropizada, com ocorrência de pastagem em seu entorno; e uma outra vereda, também antropizada, com a ocorrência de culturas anuais (agricultura) em seu entorno. As coletas foram feitas nos meses de abril e maio de 2008, ao longo de linhas de referência dispostas, segundo sua posição no relevo, nos terços superior, médio e inferior de uma das vertentes, acompanhando de modo aproximado o sentido da linha de drenagem da vereda. Foram colhidas amostras em três profundidades: 0-10 cm; 10-20 cm e 20-40 cm. As variáveis estudadas foram: textura, pH em CaCl2 0,01 M; micronutrientes (Cu, Fe, Mn, Zn e B), macronutrientes (P, K, Ca, Mg e S), teor de Al e acidez potencial (H+Al) e teor de matéria orgânica do solo (MOS). Verifica-se que os teores de argila na região inferior do relevo são maiores em ambientes antropizados e os teores de silte são maiores na vereda adjacente à área agrícola. No terço inferior do relevo, os teores de MOS são menores em veredas adjacentes a pastagens e áreas agrícolas. Na vereda conservada a saturação por bases é maior no terço inferior e, nessa mesma posição, a acidez e o teor de alumínio são menores do que nos terços médio e superior, ocorrendo o inverso em ambientes agropecuários.

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