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.
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Showing 1 to 20 of 35 for “"fine roots"”.
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Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? : a study on Pinus resinosa in Minnesota, USA
… stands in Minnesota, USA were surveyed and fine and coarse roots from stands were analysed for nitrogen isotopes in an attempt to determine if fire effects nitrogen cycling. Fire increased the % nitrogen of coarse roots and changed the ratio of C: N. It may also decrease the depth of the …
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Can nitrogen isotopes be used to detect the effects of burning on nitrogen cycling? A study on Pinus resinosa in Minnesota, USA
… stands in Minnesota, USA were surveyed and fine and coarse roots from stands were analysed for nitrogen isotopes in an attempt to determine if fire effects nitrogen cycling. Fire increased the % nitrogen of coarse roots and changed the ratio of C: N. It may also decrease the depth of the …
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Struktura zbiorowisk grzybów ektomykoryzowych w gradiencie środowiskowym
… depends on directional changes occurring in fine roots diameter (< 2 mm) in particular on changes within mycorrhizal fungal communities, enabling plant growth in diverse habitats. Fine roots consist of compartments that perform different functions: absorptive fine roots are mainly involved in …
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Effects of Elevated Atmospheric CO2 on Root Dynamics, Biomass and Architecture in a Scrub-Oak Ecosystem at Kennedy Space Center, Florida
… Large belowground structures, in addition to fine roots, are of particular interest because of their role in carbon sequestration. Non-destructive methods, including ground-penetrating radar (GPR) and minirhizotron observation tubes, were used to investigate effects of elevated CO<sub>2</sub> …
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Root Regeneration of Transplanted Trees in Relation to the Status of Carbohydrate Levels and Root Invading Fungi
… general, the vertical distribution of the major roots showed the greatest development at the soil depth of 13-38 cm, with limited growth in the top 12 cm, and decreasing development at depths below 38 cm. The north quadrant of the root systems of these trees was more developed than any other …
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Ecology of Root-Feeding Insect Assemblages in Fire-Manipulated Longleaf Pine-Wiregrass Ecosystems
… vegetative composition, soil resources, and fine root standing mass influence the structure of root-feeding insect assemblages? (2) What types of roots do root-feeding insects eat, and do they forage selectively? (3) Do root-feeding insects influence fine root productivity? To address these …
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Belowground Carbon Budget and Nutrient Uptake of Temperate Forest Species in Response to Elevated Carbon Dioxide and Temperature
… respiration. Maintenance respiration of attached fine roots was measured on mature loblolly pine and sweetgum (Liquidambar styraciflua ) growing in atmospheric CO2 elevated by 200 mu1 1 -1 above ambient. Fine root maintenance respiration on a mass basis was significantly lower in the elevated CO2 …
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Fine root dynamics in the Boreal Forest of northern Saskatchewan, Canada
The study of fine roots (FR) (roots < 2 mm in diameter) in the boreal forests has become a focus of many forest researchers in the past decade in an effort to better understand belowground processes and improve current carbon (C) models to better predict possible C sinks and sources. The objectives …
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Biomass and Nutrient Studies of Selected Tree Species of Natural and Plantation Forests: Implications for a Sustainable Management of the Munessa-Shashemene Forest, Ethiopia
… objectives of this study are to: 1) quantify the fine roots and aboveground biomass of selected tree species in both natural and plantation forests; 2) quantify the macronutrient stocks of the fine roots and aboveground components of selected trees species in both natural and plantation forests; …
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The effect of forest fertilization on the ectomycorrhizae of western hemlock (tsuga heterophylla)
… both treated and control plots, total number of fine roots and number of basidiomycetousmycorrhizae remained constant while Cenococcum mycorrhizae decreased and those lacking mantles increased. As the observed changes were independent of treatment level and pH, it is assumed that colonization was …
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Effects of 11 Years of CO2 Enrichment on Root Biomass and Spatial Distribution in a Florida Scrub-Oak Ecosystem
… radar (GPR) were used to measure fine root (< 2 mm diameter) and coarse root (> 5 mm diameter) biomass, respectively. After 11 years of CO<sub>2</sub> enrichment, there was a trend of greater total root biomass under elevated CO<sub>2</sub>. Fine root biomass exhibited a pattern of …
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Rivalry for nutrient resources : is there competition below ground between leguminous trees and grasses in a mesic and arid savanna in the Kruger National Park?
… in savannas. This study describes the fine root-distribution of dominant leguminous C₃ trees and C₄ grasses relative to soil nitrogen, phosphorus and water profiles using stable carbon and nitrogen isotope ratios (of the fine roots). The study occurs on a mesic savanna (737 mm MAP) site …
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Stable isotope analysis as an indicator of tree and grass rooting depth in a mesic African savanna
… 20-30 cm. Significantly higher densities of tree fine roots were found under canopy cover than in the open. Grass rooting followed similar patterns in both open and canopy sites, only dominating in the upper 30 cm of the open sites. Contrary to what was expected, tree fine root density increased …
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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?
… this study I determine whether the existence of fine roots in the soil profile necessarily indicates root activity. I also aim to determine the effect of increased water and nitrogen availability on root activity of trees and grasses. Pits of 20 x 20 em were dug to a depth of 40 em in plots that …
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Detecting Change in Belowground Carbon Stocks: Statistical Feasibility and Future Opportunities from Loblolly Pine Forests
… material, O horizon, mineral soil, detritus, fine roots) in planted loblolly pine stands by compiling statistical distributions from existing databases. We performed power analyses to quantify minimum detectable change in each subpool given current sample sizes, as well as minimum sample sizes …
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IS KIN RECOGNITION IN CAKILE EDENTULA AFFECTED BY NUTRIENT AVAILABILITY?
… to belowground competition is by allocation to fine roots in order to acquire the limited resources. However, this phenotypic plasticity can be costly as it assigns resources away from reproduction. Being able to recognize the relatedness of one′s neighbours and preferentially compete with …
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Spatial and competitive responses of tree and grass roots to increased nutrients and water in semi-arid African savanna
… and associated relationships between tree-grass roots prevents predictions of future responses of these ecosystems to rainfall and nutrient changes. Here I show that grasses are strongly favoured with increased resource availability in a semi-arid African savanna. I used δ¹³C values of the …
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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 …
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