Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 21 for “"tree roots"”.
-
Environmental Influences on Tree-driven Karst Bedrock Physical Weathering
<p>The role of tree roots as stressors that contribute to physical weathering processes and thus soil generation remains an open question in critical zone science. While evidence suggests roots may be able to damage rock by accessing pre-existing fractures, where they can expand due to water uptake …
-
Trees and Structural Soil as a Stormwater Management System in Urban Settings
… We propose a system of structural soil and trees that can be incorporated beneath pavement. Structural soil has a high load-bearing capacity yet is engineered to support tree root growth. Stormwater is directed into a structural soil reservoir below the pavement where tree roots can also …
-
The Spatial Relationship Between Septic System Failure and Environmental Factors in Washington Township, Marion County, Indiana
… ways environmental variables such as soil type, tree roots, degree of slope, and impervious surfaces affect on-site wastewater treatment systems. It also discusses the effects each of these variables may have on a septic system, and the resulting impact a compromised system may have on the …
-
The effects of different concentrations of phosphite on ectomycorrhiza formation by Pisolithus tinctorius in Castanea dentata
… the mutualistic symbioses between tree roots and certain soil fungi, and the phosphites themselves may be phytotoxic at high doses. Container-grown chestnut seedlings were treated with six phosphite solutions ranging from 0.0g/l to 12g/l both with and without a spore inoculation of …
-
A Study of GPR Performance in the Presence of Buried Biomass
… in the presence of buried biomass (e.g., tree roots) was investigated by using two approaches: experimental measurements and numerical simulations. For the former, two areas known to contain high and low root densities were selected. GPR measurements were performed using the OSU/ESL radar …
-
The evaluation of metham sodium and dichlobenil impacts on activated sludge nitrification
… uses metham sodium and dichlobenil to remove tree roots from municipal sewer and storm drain lines. One or more of the chemicals in this process, or their degradation products, have been suspected of disrupting the nitrification process in waste treatment plants downstream of the points of …
-
The lazy root : Will a change in the rainfall regime or increased anthropogenic nitrogen result in an alteration in the competitive balance between trees and grassed in a semi-arid South Africa savanna?
In an attempt to determine why trees and grasses are able to coexist in savannas, Walter (1971) first proposed the root niche separation model for savannas which suggests that trees and grasses have differential access to water due to spatial differences in their rooting profiles. Subsequent …
-
Estimating the Hausdorff dimension
… The Hausdorff dimensions of nursery-grown tree roots were estimated, and it was found that the dimension is related to the probability of the tree’s survival when the tree is planted in the wild. The dimensions of Julia sets and of the Hénon attractor were also investigated. A computer …
-
The Influence of Trees on Soil Hydraulic Properties : Species Effects and the Provision of Ecosystem Services.
Trees contribute to a number of important ecosystem services through their influence on soil properties and functions, including water purification and regulation. Forest soils tend to have a higher saturated hydraulic conductivity (Ks) than soils under other vegetation, so the establishment of …
-
The influence of leaf litter and plants on soil respiration before, during and after a severe drought
… of leaf litter and the presence or absence of tree roots. In both experiments, soil respiration increased with litter inputs and decreased strongly during drought. However, I observed a larger pulse of soil CO2 efflux in response to litter inputs compared to rewetting after drought. In the …
-
Dealing with contaminated land in the ‘New Regime’: an appraisal of the use of plants as biomonitors for metal contamination analysis and risk assessment for a former landfill site in Greenwich
… become available to the surrounding biota. Trees and plants growing in the vicinity of a contaminated site may provide such a historic record. There have been few studies on their role as biomarkers to identify metal mobility or bioavailability for continuous monitoring purposes. The aim of …
-
Measuring Root Growth Response to Nitrogen Fertilization Rates in Young Pecan Seedlings Using the Minirhizotron Method
… how N affects the establishment of pecan tree roots, specifically fine roots (0-2 mm) responsible for nutrient uptake. The objectives of this study are to: 1) determine how fine root growth is impacted by five rates of N fertilizer and 2) pinpoint times in the growing season when fine root …
-
Mycorrhizal fungus communities of Douglas-fir (Pseudotsuga menziesii) seedlings and trees: effects of proximity to residual trees
… (Pseudotsuga menziesii (Mirb.) Franco) trees in partially harvested stands on seedling growth and colonization by ectomycorrhizal fungi (EMF) is not well understood. To investigate this, Douglas-fir seedlings were planted near (<6 m) and far (>16 m) from 44- to 72-year-old residual …
-
Rehabilitation of Severely Compacted Urban Soil to Improve Tree Establishment and Growth
Land development restricts tree growth by damaging soil structure and removing organic matter. Mechanical loosening and organic amendment may improve soil physical properties and tree establishment and growth. Effects of typical post-construction practice and improved methods of soil restoration on …
-
THE EFFECTS OF WHOLE TREE HARVESTING ON SITE HYDROLOGY AND SOIL STRUCTURE AT BEDDGELERT FOREST, N. WALES, UK
… hydrologies of one forested and one whole tree harvested site. Particular attention was paid to the influence of trees both directly on soil water pathways and indirectly on soil characteristics. Atmospheric inputs were monitored for the slope and individual plots for one year. In spite of …
-
The role of life history traits for coexistence and forest recovery after disturbance – a modelling perspective. Towards a better understanding of species-rich forests
… different compositions of life history traits in trees. This thesis investigates the role of tree life history traits (growth, mortality and recruitment) on different processes structuring species-rich forests. Our study system is a montane rainforest located in the Tropical Andes hotspot of …
-
Pedogenic carbonates in loess formation rates, formation conditions and source apportionment assessed by isotopes and molecular proxies
… special form of pedogenic carbonates (calcified roots), from a loess-paleosol sequence for paleoenvironmental studies. In loess as a common soil parent material, initial CaCO3 recrystallization rates were successfully determined with the 14C isotopic exchange approach by exposing loess to …
-
Modelling the effects of soil variability and vegetation on the stability of natural slopes.
… of vegetation, in particular the effect of tree root reinforcement, have a significant effect on the stability of a natural slope. However, in practice, these factors are not commonly considered in routine slope stability analysis. This is due mainly to the fact that the effects of soil …
-
Effects of native forest and pastoral land use on the population dynamics and trophic role of the New Zealand freshwater crayfish Paranephrops planifrons (Parastacidae)
… forest streams. However, the removal of riparian trees (particularly the loss of their root systems) seems to have undermined the stability of habitat available to crayfish. Habitats of crayfish in native forest streams were primarily tree roots, undercut banks, and accumulations of woody debris. …
-
A physiological basis to crop improvement and agronomic development
… systems associated with adjacent N₂ fixing trees, in terms of hydraulic redistribution, N availability and crop yields. In this thesis, the proxy-based approach to crop selection was defined as a surrogate-based (proxy and surrogate used interchangeably) screening of cultivars for …
Page 1 of 2