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41	Spatial Heterogeneity of Ecosystem Metabolism in a Shallow Wetland Rackliffe, Daniel Riley 01 December 2014 (has links) (PDF) Spatial heterogeneity in ecosystem metabolism may play a critical role in determining ecosystem functions. Variation in ecosystem metabolism between macrophyte patches in shallow wetlands at the extremes of freshwater habitats has not been investigated. We estimated ecosystem metabolism in mesocosms containing different macrophytes using 24-hour oxygen curves to test our hypotheses: (1) net aquatic production (NAP) during spring and summer would be similar among algal patches (metaphyton and Chara), (2) NAP in algal patches would be greater than patches dominated by the vascular plant Potamogeton foliosus, (3) heterotrophy and anaerobiosis would be greatest in patches dominated by Lemna, and (4) the pond would be autotrophic in the spring and fall but heterotrophic in the summer. We found that different patches generated differences in NAP but not always as we predicted. NAP was different among algal patches in the spring and summer, and only metaphyton was more heterotrophic than P. foliosus. In the summer Chara and Lemna patches were heterotrophic and metaphyton became autotrophic. As predicted, the pond was net autotrophic in the spring and heterotrophic in the summer with an absence of patchiness in fall attributed to the dominance of Lemna. This research suggests the importance of macrophyte patchiness in wetlands in determining patterns of ecosystem metabolism despite challenges in measuring 24 hour oxygen curves (e.g. oxygen supersaturation). Consequently, macrophyte traits may be important in determining spatial heterogeneity of ecosystem metabolism in shallow ponds. ecosystem metabolism wetlands diel oxygen primary production respiration GPP NAP Chara Potomogeton foliosus metaphyton Lemna autotrophic heterotrophic hypoxia Hobble Creek submersed macrophytes Biology
42	Insights into Autotrophic Activities and Carbon Flow in Iron-Rich Pelagic Aggregates (Iron Snow) Li, Qianqian, Cooper, Rebecca E., Wegner, Carl-Eric, Taubert, Martin, Jehmlich, Nico, von Bergen, Martin, Küsel, Kirsten 05 May 2023 (has links) Pelagic aggregates function as biological carbon pumps for transporting fixed organic carbon to sediments. In iron-rich (ferruginous) lakes, photoferrotrophic and chemolithoautotrophic bacteria contribute to CO2 fixation by oxidizing reduced iron, leading to the formation of iron-rich pelagic aggregates (iron snow). The significance of iron oxidizers in carbon fixation, their general role in iron snow functioning and the flow of carbon within iron snow is still unclear. Here, we combined a two-year metatranscriptome analysis of iron snow collected from an acidic lake with protein-based stable isotope probing to determine general metabolic activities and to trace 13CO2 incorporation in iron snow over time under oxic and anoxic conditions. mRNA-derived metatranscriptome of iron snow identified four key players (Leptospirillum, Ferrovum, Acidithrix, Acidiphilium) with relative abundances (59.6–85.7%) encoding ecologically relevant pathways, including carbon fixation and polysaccharide biosynthesis. No transcriptional activity for carbon fixation from archaea or eukaryotes was detected. 13CO2 incorporation studies identified active chemolithoautotroph Ferrovum under both conditions. Only 1.0–5.3% relative 13C abundances were found in heterotrophic Acidiphilium and Acidocella under oxic conditions. These data show that iron oxidizers play an important role in CO2 fixation, but the majority of fixed C will be directly transported to the sediment without feeding heterotrophs in the water column in acidic ferruginous lakes. info:eu-repo/classification/ddc/570 ddc:570
43	Zur Struktur und Funktion regulatorischer Elemente des cbb-Regulons in Ralstonia eutropha / Structure and function of regulatory elements of the cbb regulon in Ralstonia eutropha Jeffke, Thomas 31 January 2001 (has links) No description available. 570 Biowissenschaften, Biologie Mathematics and Computer Science cbb regulation transkription transkriptionsregulation CO2-Assimilation Ralstonia eutropha CbbR cbb-operon gelretardation regulator Autotrophie autotroph PhcA CO2 Affinitätschromatographie cbb regulation transcription transcriptional regulation CO2 assimilation Ralstonia eutropha CbbR cbb operon gel retardation regulator autotrophy autotrophic PhcA CO2 affinity chromatography W
44	Drought effects on soil carbon dioxide efflux in two ecosystems in Central Sulawesi, Indonesia van Straaten, Oliver 12 May 2010 (has links) No description available. 500 Naturwissenschaften Forest Sciences and Forest Ecology Indonesien Sulawesi agroforest Dürre Theobroma Cacao Gliricidia sepium Bodenatmung Kohlendioxid Bodenfeuchte ENSO Kohlendioxid Produktion Indonesia Sulawesi agroforestry drought Theobroma cacao Gliricidia sepium soil respiration carbon dioxide soil moisture ENSO carbon dioxide production autotrophic respiration heterotrophic respiration litter respiration 48.32 YPA 000: Forstliche Bodenkunde YYZ 300: Asien {Forstwesen regional}

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