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Revegetation with Carex nebrascensis and Carex utriculata following reconstruction in a NE Oregon meadow stream /Quistberg, Sarah E. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.
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A Study of Sedge-Dominated Areas in the Uinta MountainsBriggs, George Murchie 01 May 1978 (has links)
Twenty- six sedge-dominated sites in the Uinta Mountains of northeastern Utah were studied. These sites could be placed into two categories, wetland sites (those with water-saturated soils) and alpine tundra sites.
The alpine sites had above-ground standing crops between 37 and 206 g/m2 • The soils were sandy and low in nutrients. Indirect gradient analysis of the alpine sites showed a relationship between soil stability and vegetation. No other factors were found to be related to overall vegetation patterns.
The wetland sites were dominated by different Carex species than the alpine sites. These wetlands were often patches of monotypic stands. Above- ground standing crop values ranged from 28 360 g/m2 and were strongly dependent upon the stagnation of the water on the site.
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Effects of Reed Sedge Peat on Lambs at Weaning with Regard to Stress and Apparent Nutrient DigestibilityPrice, Rhianwedd O 03 May 2019 (has links)
For this study 14 lambs were obtained, which were split into two groups; a control group (CON) and a group that was supplemented Reed Sedge Peat (RSP). We wanted to test whether RSP could decrease stress at weaning, increase immune response and also increase digestibility of the animal. Lambs were subjected to an ACTH challenge 48 hours post weaning. After weaning (d 28 of study) 10 of the lambs (5 CON; 5 RSP) also underwent a digestibility challenge. We found that there was no difference (P = 0.8764) within cortisol concentration during the weaning portion of the study between the two treatment groups. During the ACTH challenger there was a difference between RSP group and CON, where RSP had a decrease in cortisol concentration (P = 0.0892). There was no difference in blood cell parameters, except for SEG, % (P = 0.0890) where RSP had greater % of SEG than CON group. Within the digestibility trail there was a decrease in digestibility within the RSP group compared to CON, within DM, OM, NDF and ADF (P = 0.0458; P = 0.0430; P = 0.0509; P = 0.0786; respectively).
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BIOPHYSICAL REMOTE SENSING AND TERRESTRIAL CO2 EXCHANGE AT CAPE BOUNTY, MELVILLE ISLANDGREGORY, FIONA MARIANNE 13 January 2012 (has links)
Cape Bounty, Melville Island is a partially vegetated High Arctic landscape with three main plant communities: polar semi-desert (47% of the study area), mesic tundra (31%) , and wet sedge meadows (7%). The objective of this research was to relate biophysical measurements of soil, vegetation, and CO2 exchange rates in each vegetation type to high resolution satellite data from IKONOS-2, extending plot level measurements to a landscape scale. Field data was collected through six weeks of the 2008 growing season. Two IKONOS images were acquired, one on July 4th and the other on August 2nd. Two products were generated from the satellite data: a land-cover classification and the Normalized Difference Vegetation Index (NDVI).
The three vegetation types were found to have distinct soil and vegetation characteristics. Only the wet sedge meadows were a net sink for CO2; soil respiration tended to exceed photosynthesis in the sparsely vegetated mesic tundra and polar semi-desert. Scaling up the plot measurements by vegetation type area suggested that Cape Bounty was a small net carbon source (0.34 ± 0.47 g C m-2 day-1) in the summer of 2008.
NDVI was strongly correlated with percent vegetation cover, vegetation volume, soil moisture, and moderately with soil nitrogen, biomass, and leaf area index (LAI). Photosynthesis and respiration of CO2 both positively correlated with NDVI, most strongly when averaged over the season. NDVI increased over time in every vegetation type, but this change was not reflected in any significant measured changes in vegetation or CO2 flux rates.
A simple spatial model was developed to estimate Net Ecosystem Exchange (NEE) at every pixel on the satellite images based on NDVI, temperature and incoming solar radiation. It was found that the rate of photosynthesis per unit NDVI was higher early in the growing season. The model estimated a mean flux to the atmosphere of 0.21 g C m-2 day-1 at the time of image acquisition on July 4th, and -0.07 g C m-2 day-1 (a net C sink) on August 2nd. The greatest uncertainty in the relationship between NDVI and CO2 flux was associated with the polar semi-desert class. / Thesis (Master, Geography) -- Queen's University, 2011-12-28 23:27:34.824
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CO2 exchange in a subarctic sedge fen in the Hudson Bay Lowland during two consecutive growing seasonsSwystun, Kyle A. 11 April 2011 (has links)
Net ecosystem carbon dioxide exchange (NEE) was measured using the eddy covariance (EC) technique at a wetland tundra-sedge fen near Churchill, Manitoba, Canada during two consecutive growing seasons (2007 and 2008). Mean daily NEE at the fen (DOY 157-254) was -3.5 (± 0.26 S.E.) g CO2 m-2 d-1 in 2007 and -4.6 (± 0.36) g CO2 m-2 d-1 in 2008. The fen was a net carbon dioxide (CO2) sink during both the 2007 and 2008 growing seasons of -343 (± 79) and -450 (± 87) g CO2 m-2, respectively. Mean air temperature during the summer (June 1-August 31) was about 1°C greater than the historical average (1971-2000) in 2007 and about 2°C greater in 2008. Growing season precipitation was 107.5 mm below normal in 2007 and 359.5 mm above normal in 2008. These data suggest that if future climate change brings warmer temperatures and near-to-above average precipitation maintaining the water table near the surface, similar subarctic ecosystems will experience increased gross ecosystem productivity enhancing CO2 sequestration during the growing season.
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CO2 exchange in a subarctic sedge fen in the Hudson Bay Lowland during two consecutive growing seasonsSwystun, Kyle A. 11 April 2011 (has links)
Net ecosystem carbon dioxide exchange (NEE) was measured using the eddy covariance (EC) technique at a wetland tundra-sedge fen near Churchill, Manitoba, Canada during two consecutive growing seasons (2007 and 2008). Mean daily NEE at the fen (DOY 157-254) was -3.5 (± 0.26 S.E.) g CO2 m-2 d-1 in 2007 and -4.6 (± 0.36) g CO2 m-2 d-1 in 2008. The fen was a net carbon dioxide (CO2) sink during both the 2007 and 2008 growing seasons of -343 (± 79) and -450 (± 87) g CO2 m-2, respectively. Mean air temperature during the summer (June 1-August 31) was about 1°C greater than the historical average (1971-2000) in 2007 and about 2°C greater in 2008. Growing season precipitation was 107.5 mm below normal in 2007 and 359.5 mm above normal in 2008. These data suggest that if future climate change brings warmer temperatures and near-to-above average precipitation maintaining the water table near the surface, similar subarctic ecosystems will experience increased gross ecosystem productivity enhancing CO2 sequestration during the growing season.
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Разнообразие морфологических и структурных признаков поглощающих корней четырех семейств бореальных однодольных : магистерская диссертация / Variety of morphological and structural signs of absorbing roots of four families of breal monocotsАнянова, Ю. А., Anyanova, Y. A. January 2021 (has links)
Данная работа содержит 52 страницы машинописного текста, включая 19 рисунков, 1 таблицу и 106 литературных источников. Работа посвящена изучению разнообразия совокупности признаков корней четырех семейств однодольных растений – Orchidaceae Juss., Iridaceae L., Poaceae Barnhart и Cyperaceae Juss., в условиях бореальной климатической зоны. В анализ вошли материалы, предоставленные научным руководителем (данные по строению корней представителей семейств Orchidaceae, Poaceae, Cyperaceae) и оригинальные сборы. Цель – выявить разнообразие синдромов корневых признаков у четырех семейств однодольных растений бореальной зоны. Для достижения цели были поставлены следующие задачи: изучить строение поглощающих корней представителей семейств Orchidaceae, Iridaceae, Poaceae, Cyperaceae; изучить внешние признаки корневых систем представителей семейств Orchidaceae, Iridaceae, Poaceae, Cyperaceae; сравнить комплекс количественных и качественных признаков в масштабе всей корневой системы у таксонов с разными типами микориз, а также с преобладанием немикоризных видов. С помощью классических методов структурной ботаники были изучены внешние признаки корневых систем и строение поглощающих корней. Получали микротомные срезы поглощающих корней, которые анализировали под микроскопом Leica DM 5000 в светлом поле и в синих лучах длиной волны 365 нм (флуоресцентная микроскопия). С помощью окулярмикрометра измеряли диаметр корня и стелы, толщину коры, длину корневых волосков, подсчитывали число сосудов ксилемы. На продольных препаратах определяли встречаемость корневых волосков. Число порядков ветвления корневой системы фиксировали по функциональной классификации [McCormack et al., 2015]. Установление микоризации выполняли методом световой микроскопии (Leica DM 5000; ×100) после предварительной мацерации корней в КОН и окрашивания анилиновым синим [Селиванов, 1981]. Обработка данных производилась в программе EXCEL, а с помощью программы STATISTICA был проведен однофакторный дисперсионный анализ ANOVA. Результаты исследований показали, что корни разных таксонов однодольных сильно различаются по внешнему и внутреннему строению. Были выявлены синдромы корневых признаков: Orchidaceae – толстые не ветвящиеся корни с сильно развитой специализированной микоризой, с относительно толстой корой и стелой, длинными корневыми волосками и без выраженной экзодермы; Iridaceae – толстые сильно разветвленные корни с мощной экзодермой, короткими редко встречающимися корневыми волосками и интенсивной АМ; Poaceae – тонкие разветвленные корни с невыраженной экзодермой, с короткими, часто встречающимися корневыми волосками и интенсивной АМ; Cyperaceae – тонкие, сильно разветвленные корни с хорошо развитыми корневыми волосками и другими приспособлениями к автономному почвенному питанию, АМ встречается редко. / This work contains 52 pages of typewritten text, including 19 figures, 1 table and 106 literature sources. The work is devoted to the study of the diversity of the totality of the traits of the roots of four families of monocotyledonous plants – Orchidaceae Juss., Iridaceae L., Poaceae Barnhart and Cyperaceae Juss., in the conditions of the boreal climatic zone. The analysis included materials provided by the scientific advisor (data on the structure of roots of representatives of the families Orchidaceae, Poaceae, Cyperaceae) and original collections. The goal is to identify the diversity of root trait syndromes in four families of monocotyledonous plants in the boreal zone. To achieve the goal, the following tasks were set: to study the structure of absorbing roots of representatives of the families Orchidaceae, Iridaceae, Poaceae, Cyperaceae; to study the external signs of root systems of representatives of the families Orchidaceae, Iridaceae, Poaceae, Cyperaceae; to compare the complex of quantitative and qualitative characters on the scale of the entire root system in taxa with different types of mycorrhizal, as well as with a predominance of nonmycorrhizal species. Using classical methods of structural botany, the external signs of root systems and the structure of absorbing roots were studied. Received microtome sections of absorbing roots, which were analyzed under a Leica DM 5000 microscope in a bright field and in blue beams with a wavelength of 365 nm (fluorescence microscopy). Using an eyepiece micrometer, the following was measured: the diameter of the root and stele, the thickness of the cortex, the length of root hairs, and the number of xylem vessels was counted. On longitudinal preparations, the occurrence of root hairs was determined. The number of orders of branching of the root system was fixed according to the functional classification [McCormack et al., 2015]. Mycorrhiza was determined by light microscopy (Leica DM 5000; × 100) after preliminary maceration of the roots in KOH and staining with aniline blue [Selivanov, 1981]. The data were processed using the EXCEL program, and the one-way ANOVA was carried out using the STATISTICA program. The research results showed that the roots of different monocotyledonous taxa differ greatly in their external and internal structure. Syndromes of root signs were identified: Orchidaceae – thick non-branching roots of with highly developed specialized mycorrhiza, with relatively thick bark and stele, long root hairs and without pronounced exoderm; Iridaceae – thick, highly branched roots of with powerful exoderm, short rare root hairs and intense AM; Poaceae – thin branched roots of with an indistinct exoderm, with short, frequently occurring root hairs and intense AM; Cyperaceae – thin, highly branched roots of with well-developed root hairs and other adaptations to autonomous soil nutrition, AM is rare.
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Statistical models for the long-term monitoring of songbird populations : a Bayesian analysis of constant effort sites and ring-recovery dataCave, Vanessa M. January 2010 (has links)
To underpin and improve advice given to government and other interested parties on the state of Britain’s common songbird populations, new models for analysing ecological data are developed in this thesis. These models use data from the British Trust for Ornithology’s Constant Effort Sites (CES) scheme, an annual bird-ringing programme in which catch effort is standardised. Data from the CES scheme are routinely used to index abundance and productivity, and to a lesser extent estimate adult survival rates. However, two features of the CES data that complicate analysis were previously inadequately addressed, namely the presence in the catch of “transient” birds not associated with the local population, and the sporadic failure in the constancy of effort assumption arising from the absence of within-year catch data. The current methodology is extended, with efficient Bayesian models developed for each of these demographic parameters that account for both of these data nuances, and from which reliable and usefully precise estimates are obtained. Of increasing interest is the relationship between abundance and the underlying vital rates, an understanding of which facilitates effective conservation. CES data are particularly amenable to an integrated approach to population modelling, providing a combination of demographic information from a single source. Such an integrated approach is developed here, employing Bayesian methodology and a simple population model to unite abundance, productivity and survival within a consistent framework. Independent data from ring-recoveries provide additional information on adult and juvenile survival rates. Specific advantages of this new integrated approach are identified, among which is the ability to determine juvenile survival accurately, disentangle the probabilities of survival and permanent emigration, and to obtain estimates of total seasonal productivity. The methodologies developed in this thesis are applied to CES data from Sedge Warbler, Acrocephalus schoenobaenus, and Reed Warbler, A. scirpaceus.
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Perkolierte Feststoff-Vergärung Vergleichende Untersuchungen zur Prozesssteuerung in ein- und mehrstufigen VerfahrenKrieg, Andreas Ludwig 14 May 2019 (has links)
Bei der Behandlung organische Abfälle werden zunehmend Feststoff-Vergärungsverfahren mit Perkolation eingesetzt. Sie werden bevorzugt, wenn eine Vorab-Zerstörung der Feststoffstruktur nachteilig für die Gärrest-Verwendung oder sich daraus keine ökonomischen Vorteile ergeben. Das trifft auch bei strohartiger Biomasse zu. Zur satzweisen Vergärung wurden zahlreiche Erkenntnisse publiziert. Zeitgleich wurde das Sauter-Verfahren für den kontinuierlichen Betrieb zur Anwendungsreife entwickelt sowie am Leibniz-Institut für Agrartechnik und Bioökonomie e.V. (ATB) Forschungen einer zweistufigen Variante publiziert. Erstmalig erfolgt unter Verwendung von Silagen ein Vergleich der Varianten. Einflüsse der Perkolationsintensität auf Zusammensetzung und Eigenschaften der Feststoffe und der Prozessflüssigkeit sowie auf die Kinetik der Gasbildung werden untersucht. Die Perkolatzusammensetzung variiert variantenabhängig. OTS-Belastungs-Grenzen lassen sich in erster Näherung bestimmen. Geeignete Vergleichsparameter werden dargestellt. Betreiberbefragungen und messtechnische Begleitung einer Sauter-Anlage ergänzen die Arbeit. Eine differenzierte Beurteilung der Perkolationsverfahren ist nun möglich. Betrachtet werden die Feststoffdichte im Fermenter, die TS-Gehalte im Gärstock sowie der Schwimmschicht. Die Verweilzeit der partikulären Biomasse im Fermenter ist erheblich kürzer als bisher angenommen. Das beeinflusst direkt die Hydrolyserate und mittelbar die Mikroflora im Fermenter. Nähere Untersuchungen sind erforderlich. Auch bei Perkolationsverfahren beeinflusse Substratzusammensetzung und Mahlgrad die Kinetik der Gasbildung. Die Methanausbeuten unterscheiden sich nur unwesentlich von Rührkessel-Systemen. Die Erweiterung der perkolierten Vergärung durch eine Perkolat-Methanisierungsstufe sind höhere Raum-Zeit-Ausbeuten möglich. Das erlaubt eine zeitlich gesteuerte Methanerzeugung, wobei Ausmaß und Leistungsgradient weiterer Forschung bedürfen. / Numerous research findings and experience on the batchwise fermentation of stacked biomass are available. At the same time, the percolated and continuously operated Sauter-process was developed to market maturity. Research on a two-stage variant has been carried out and published by the Leibnitz Institute for Agricultural Engineering and Bioeconomics e.V. (ATB). This paper provides for the first time a direct comparison of the above-mentioned percolated process variants using maize and sedge silages. The effects of percolation intensity on composition and properties of the solids and the process fluid as well as on the gas formation kinetics are investigated in particular. Furthermore, suitable benchmarks of the variants are identified and evaluated. The link to practice is a operators questioning and a one year lasting monitoring of a Sauter plant. The findings allow a differentiated assessment of percolation processes. Findings on solid matter density as well as on dry matter content in the fermenting stock or floating layer are presented in detail. During continuous operation, particulate biomass retention time is considerably shorter than would result from usual calculation of hydraulic retention time. It is indicated that the microflora in the fermenter is also indirectly affected. This requires further research work. It is shown that in percolation processes substrate composition and extent of grinding also dominate the gas formation kinetics, albeit to different extents. Methane yields differ under comparable load and operating parameters only marginally from yields of stirred tank systems. Composition of percolate also varies variant-specific. Findings can be used to define in a first approximation limits of volatile solid load. It has been proven that percolated solid-state fermentation with an additional percolate methanization stage allows higher space-time yields. This extra stage suits also for controlled flexible methane production.
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Makrofossilanalys som ekologiskt verktyg : En metodutvärderingPettersson, Siri January 2017 (has links)
Approximately 50 percent of all endangered species in Scandinavia are associated with old agricultural landscapes. During the agricultural industrialization of the past century the traditional practices and methods that created these environments have been phased out. This has brought on a serious decline and fragmentation of biomes that many endangered species depend on. Knowledge of traditional agricultural landscapes and their species dynamics is needed to make well informed decisions regarding their care and restoration. One way to acquire such knowledge is to study fossil plant remnants from old agricultural contexts. In this study sub-fossil Cyperaceae achenes were analyzed in an attempt to identify them. The achenes had been preserved in three Iron Age wells (80-980 AD) at the Gilltuna settlement in central Sweden and were found during an archeological investigation in 2010. The purpose of this study was to identify the achenes to species level, make conclusions about the ecology of the surrounding landscape, and construct simple species identification key as well as evaluate archaeobotany as an ecological tool. The identification attempt resulted in 14 determined species, which were in consistency with previous landscape analyses made using ecological species distribution. The resulting identification key is a suggestion, to be expanded in the future. This method can undoubtedly provide further knowledge of prehistoric and historical biomes, but in order to draw useful conclusions the identification technique further as well as knowledge of present regional ecology must be developed, especially concerning different Cyperaceae species‟ response to different kinds of stress.
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