Techn. Universiẗat, Habil.-Schr., 2005--München. / Erscheinungsjahr an der Haupttitelstelle: 2004.

No presente trabalho buscaram-se formas adequadas de produzir micélio de Ceriporiopsis subvermispora em culturas submersas, com o objetivo de preparar inóculo destinado ao processo de biopolpação. A obtenção de inóculo pode ser considerada uma etapa chave na biopolpação, visto que atualmente não existem processos industriais estabelecidos para a produção de micélio de basidiomicetos em quantidades compatíveis com a demanda prevista no processo. Mesmo uma planta industrial pequena de biopolpação (200 ton de polpa/dia) pode demandar cerca de 1 kg de micélio seco/dia, considerando-se as cargas de inoculação de 5 g de micélio seco/ton de madeira tratada. Desta forma, o sucesso desse processo pode depender de um baixo custo da produção dos inóculos fúngicos em larga escala. Os experimentos realizados consistiram inicialmente no crescimento do fungo em Erlenmeyers de 250 mL contendo 20 mL de meio líquido. Numa segunda etapa, os experimentos foram conduzidos em biorreatores de 1,5 L (Bioflo-NewBrunswick) e por último em um biorreator de 14 L. No último caso, o biorreator em questão foi especialmente desenhado e construído com o intuito de minimizar efeitos de cisalhamento da hifa durante o cultivo, mantendo ainda níveis adequados de aeração. Em Erlenmeyer foram feitos cultivos utilizando meio composto por 2,4% de extrato de batata e 0,7% de extrato de levedura (DB-EL), além de um meio potencialmente de menor custo que era composto por 2,0% de sacarose e 3,2% de milhocina (SM). A biomassa total obtida nos cultivos com meio SM foi compatível com aquela obtida no meio DB-EL. Os cultivos subsequentes realizados em biorreator utilizaram então o meio SM. O maior nível de biomassa fúngica obtida nos cultivos com biorreator agitado por pás (1,5 L) foi de 7,0 g/L, após 12 dias de crescimento. As maiores produtividades foram observadas a partir do 7o dia de cultivo, atingindo 0,93 g/L.dia quando a biomassa total era de 6,5 g/L. No biorreator de 14 L foram realizados 3 cultivos em condições diferenciadas (denominados de A, B e C). No cultivo A não houve intervenção em relação à correção de pH ou nível de nutrientes disponíveis ao longo de 14 dias. No cultivo B foi realizado o controle do pH a fim de mantê-lo entre 4,0 e 5,0. No cultivo C foi realizada a adição de sacarose correspondente a uma reposição de 5 g/L após 5 dias de crescimento. Os cultivos foram monitorados quanto à biomassa produzida, o pH, o teor de açúcar residual e o nível de O2 dissolvido. De forma geral, o acúmulo de biomassa sempre foi seguido pelo consumo de açúcares, pela diminuição nos níveis de O2 dissolvido e pela tendência de elevação do pH. A maior quantidade de biomassa foi obtida no cultivo C (14,1 g/L), correspondendo a uma produtividade de 1,72 g/L.dia. O surgimento de clamidósporos foi verificado em todos os tipos de cultivo, sendo que no cultivo C (em biorreator de 14 L) foi observada a menor quantidade de clamidósporos. Isso sugeriu que nessa situação houve melhores condições de crescimento para o fungo e menor estresse nutricional ou induzido por cisalhamento. A viabilidade dos inóculos preparados para a efetiva colonização da madeira foi testada e indicou que o inóculo produzido no biorreator de 14 L, tanto micélio como clamidósporos, foi efetivo para colonizar Eucalyptus grandis. / The present work evaluated suitable systems for producing Ceriporiopsis subvermispora mycelium in submerged cultures. Mycellium produced was used in subsequent inoculation of wood chips in biopulping processes. The development of appropriated technologies for producing large amounts of inoculum may be a key step in biopulping, since currently there are no established processes designed to produce basidiomycetes mycelium to supply biopulping demands. Even a small biopulping plant (200 ton pulp / day) may require about 1 kg of dry mycelium/day, taking into account inoculation of 5 g of dry mycelium/ton of wood to be biotreated. Thus, the success of this process may depend on the low cost of large scale fungal inoculum production. The experiments were conducted initially in 250 mL Erlenmeyer flasks containing 20 mL of liquid medium. In a second step, the experiments were conducted in bioreactors of 1.5 L (Bioflo-NewBrunswick) and finally in a bioreactor of 14 L. In the latter case, the bioreactor has been designed and constructed in order to minimize the effects of shear stress during cultivation and supply suitable aeration levels. Culture broths were composed of 2.4% potato extract and 0.7% yeast extract (BD-EL) or 2.0% sucrose and 3.2% of corn steep liquor (SM) that represent a potentially lower cost culture broth. The total biomass obtained in flask-cultures with SM broth was similar to that obtained with DB-EL. Cultures performed in the subsequent bioreactor used then the SM broth. The higher level of fungal biomass obtained in the cultures performed in the 1.5 L-stirred bioreactor was 7.0 g/L after 12 days. The highest mycelium yield was observed from the 7th day of cultivation, reaching 0.93 g/L.day and 6.5 g/L total biomass. In the 14 L-bioreactor, 3 experiments were performed in different conditions (called A, B and C). In cultivation A, no interventions were performed to correct the culture pH or the level of available nutrients over 14 days of culturing. In culture B pH was controlled to keep it between 4.0 and 5.0. Cultivation C was carried out with addition of sucrose (final concentration of 5 g/L) after 5 days of growth. All cultures were monitored with basis on the biomass produced, culture pH, residual sugar content and dissolved O2 levels. In general, biomass accumulation was always followed by sugar consumption, decrease in dissolved O2 levels and a rising tendency for the pH values. The highest biomass amount was obtained in culture C (14.1 g / L), corresponding to a yield of 1.72 g/L.day. The presence of clamydospores was observed in all cultures, whereas in culture C (in 14 L bioreactor) it appeared at the lowest amounts. This fact suggested that culture C presented the lowest stress level for the fungus, including low hypha shear stress and low nutritional depletion. The viability of inoculum prepared, both mycelium and clamydospores, was checked by culturing them on Eucalyptus grandis wood chips. Both inoculum types (prepared from the 14 L-bioreactor) were efficient on colonizing wood chips and to produce the manganese peroxidase enzyme.

No presente trabalho buscaram-se formas adequadas de produzir micélio de Ceriporiopsis subvermispora em culturas submersas, com o objetivo de preparar inóculo destinado ao processo de biopolpação. A obtenção de inóculo pode ser considerada uma etapa chave na biopolpação, visto que atualmente não existem processos industriais estabelecidos para a produção de micélio de basidiomicetos em quantidades compatíveis com a demanda prevista no processo. Mesmo uma planta industrial pequena de biopolpação (200 ton de polpa/dia) pode demandar cerca de 1 kg de micélio seco/dia, considerando-se as cargas de inoculação de 5 g de micélio seco/ton de madeira tratada. Desta forma, o sucesso desse processo pode depender de um baixo custo da produção dos inóculos fúngicos em larga escala. Os experimentos realizados consistiram inicialmente no crescimento do fungo em Erlenmeyers de 250 mL contendo 20 mL de meio líquido. Numa segunda etapa, os experimentos foram conduzidos em biorreatores de 1,5 L (Bioflo-NewBrunswick) e por último em um biorreator de 14 L. No último caso, o biorreator em questão foi especialmente desenhado e construído com o intuito de minimizar efeitos de cisalhamento da hifa durante o cultivo, mantendo ainda níveis adequados de aeração. Em Erlenmeyer foram feitos cultivos utilizando meio composto por 2,4% de extrato de batata e 0,7% de extrato de levedura (DB-EL), além de um meio potencialmente de menor custo que era composto por 2,0% de sacarose e 3,2% de milhocina (SM). A biomassa total obtida nos cultivos com meio SM foi compatível com aquela obtida no meio DB-EL. Os cultivos subsequentes realizados em biorreator utilizaram então o meio SM. O maior nível de biomassa fúngica obtida nos cultivos com biorreator agitado por pás (1,5 L) foi de 7,0 g/L, após 12 dias de crescimento. As maiores produtividades foram observadas a partir do 7o dia de cultivo, atingindo 0,93 g/L.dia quando a biomassa total era de 6,5 g/L. No biorreator de 14 L foram realizados 3 cultivos em condições diferenciadas (denominados de A, B e C). No cultivo A não houve intervenção em relação à correção de pH ou nível de nutrientes disponíveis ao longo de 14 dias. No cultivo B foi realizado o controle do pH a fim de mantê-lo entre 4,0 e 5,0. No cultivo C foi realizada a adição de sacarose correspondente a uma reposição de 5 g/L após 5 dias de crescimento. Os cultivos foram monitorados quanto à biomassa produzida, o pH, o teor de açúcar residual e o nível de O2 dissolvido. De forma geral, o acúmulo de biomassa sempre foi seguido pelo consumo de açúcares, pela diminuição nos níveis de O2 dissolvido e pela tendência de elevação do pH. A maior quantidade de biomassa foi obtida no cultivo C (14,1 g/L), correspondendo a uma produtividade de 1,72 g/L.dia. O surgimento de clamidósporos foi verificado em todos os tipos de cultivo, sendo que no cultivo C (em biorreator de 14 L) foi observada a menor quantidade de clamidósporos. Isso sugeriu que nessa situação houve melhores condições de crescimento para o fungo e menor estresse nutricional ou induzido por cisalhamento. A viabilidade dos inóculos preparados para a efetiva colonização da madeira foi testada e indicou que o inóculo produzido no biorreator de 14 L, tanto micélio como clamidósporos, foi efetivo para colonizar Eucalyptus grandis. / The present work evaluated suitable systems for producing Ceriporiopsis subvermispora mycelium in submerged cultures. Mycellium produced was used in subsequent inoculation of wood chips in biopulping processes. The development of appropriated technologies for producing large amounts of inoculum may be a key step in biopulping, since currently there are no established processes designed to produce basidiomycetes mycelium to supply biopulping demands. Even a small biopulping plant (200 ton pulp / day) may require about 1 kg of dry mycelium/day, taking into account inoculation of 5 g of dry mycelium/ton of wood to be biotreated. Thus, the success of this process may depend on the low cost of large scale fungal inoculum production. The experiments were conducted initially in 250 mL Erlenmeyer flasks containing 20 mL of liquid medium. In a second step, the experiments were conducted in bioreactors of 1.5 L (Bioflo-NewBrunswick) and finally in a bioreactor of 14 L. In the latter case, the bioreactor has been designed and constructed in order to minimize the effects of shear stress during cultivation and supply suitable aeration levels. Culture broths were composed of 2.4% potato extract and 0.7% yeast extract (BD-EL) or 2.0% sucrose and 3.2% of corn steep liquor (SM) that represent a potentially lower cost culture broth. The total biomass obtained in flask-cultures with SM broth was similar to that obtained with DB-EL. Cultures performed in the subsequent bioreactor used then the SM broth. The higher level of fungal biomass obtained in the cultures performed in the 1.5 L-stirred bioreactor was 7.0 g/L after 12 days. The highest mycelium yield was observed from the 7th day of cultivation, reaching 0.93 g/L.day and 6.5 g/L total biomass. In the 14 L-bioreactor, 3 experiments were performed in different conditions (called A, B and C). In cultivation A, no interventions were performed to correct the culture pH or the level of available nutrients over 14 days of culturing. In culture B pH was controlled to keep it between 4.0 and 5.0. Cultivation C was carried out with addition of sucrose (final concentration of 5 g/L) after 5 days of growth. All cultures were monitored with basis on the biomass produced, culture pH, residual sugar content and dissolved O2 levels. In general, biomass accumulation was always followed by sugar consumption, decrease in dissolved O2 levels and a rising tendency for the pH values. The highest biomass amount was obtained in culture C (14.1 g / L), corresponding to a yield of 1.72 g/L.day. The presence of clamydospores was observed in all cultures, whereas in culture C (in 14 L bioreactor) it appeared at the lowest amounts. This fact suggested that culture C presented the lowest stress level for the fungus, including low hypha shear stress and low nutritional depletion. The viability of inoculum prepared, both mycelium and clamydospores, was checked by culturing them on Eucalyptus grandis wood chips. Both inoculum types (prepared from the 14 L-bioreactor) were efficient on colonizing wood chips and to produce the manganese peroxidase enzyme.

Submitted by William Justo Figueiro (williamjf) on 2015-06-12T12:24:30Z No. of bitstreams: 1 4.pdf: 2382758 bytes, checksum: 4c6120c8307739a15287afe6bbb8a4e0 (MD5) / Made available in DSpace on 2015-06-12T12:24:31Z (GMT). No. of bitstreams: 1 4.pdf: 2382758 bytes, checksum: 4c6120c8307739a15287afe6bbb8a4e0 (MD5) Previous issue date: 2010-06 / UNISINOS - Universidade do Vale do Rio dos Sinos / PRÓ SINOS - Consórcio Público de Saneamento Básico da Bacia Hidrográfica do Rio dos Sinos / COMITESINOS - Comitê de Gerenciamento da Bacia Hidrográfica do Rio dos Sinos / FNMA - Fundo Nacional de Meio Ambiente do Ministério do Meio Ambiente / SEMA - Secretaria Estadual de Meio Ambiente do Rio Grande do Sul / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho fundamentou-se no monitoramento de um sistema composto de três Biofiltros Aerados Submersos (BAS)multi-estágio, aplicado ao pós-tratamento de efluente de reator anaeróbio alimentado com mistura de lixiviado de aterro sanitário e esgoto doméstico, sendo testados três diferentes meios suporte: tampas e gargalo de garrafa PET, pedra britada nº4 e anéis Pall, sendo denominados BAS 1, 2 e 3. Os BAS são reatores com biomassa fixa, de forma que os microrganismos se aderem ao meio suporte formando biofilme. Neste sentido, este trabalho objetivou verificar a ocorrência de microbiota nitrificante no período de partida do sistema, convencionado em 90 dias. Foi avaliada a presença de bactérias nitrificantes através de técnicas de reação em cadeia da polimerase (PCR) e técnica do número mais provável (NMP), visando a quantificação dos microrganismos, especificamente Nitrosomonase Nitrobacter. A presença destes foi confirmada pelos resultados das análises físico-químicas e pela técnica de NMP.A contagem de bactérias do gênero Nitrosomonas para os 3 BAS apresentou um perfil semelhante com valores entre 7,8 x 101 e >1,6 x 105(BAS1); 7,8 x 101e 1,6 x 105(BAS2) e 2,4 x 101e 9,2 x 104(BAS3). O mesmo comportamento foi observado para bactérias do gênero Nitrobacter, cujos valores variaram entre: < 1,8 x 101e 1,6 x 104(BAS1); 1,8 x 101e 2,4 x 103(BAS2); 1,7 x 01e 3,5 x 103 (BAS3). As contagens de bactérias do gênero Nitrobacter apresentaram-se menores em todos os reatores. Os teores de nitrato avaliados no efluente mostraram a ocorrência de um acréscimo na concentração ao longo do período monitorado em todos os reatores apresentando os seguintes valores: 74 a 922 mg/L (BAS 1), 95 a 910 mg/L (BAS 2) e 33 a 910 mg/L (BAS 3), o que pode ser relacionado com o aumento da presença de bactérias nitrificantes, conforme resultados do NMP. As análises de PCR, entretanto, foram prejudicadas possivelmente pela presença de substâncias inibidoras dificultando a amplificação. Neste estágio toda a matéria orgânica facilmente biodegradável já havia sido consumida pelo pré-tratamento anaeróbio a jusante dos BAS, permanecendo no afluente aos BAS apenas matéria orgânica recalcitrante, o que dificultou o desenvolvimento de um biofilme adequado e possivelmente a amplificação do DNA das bactérias nitrificantes presentes no sistema. Esta pesquisa é parte de dois projetos amplos, o Programa de Apoio ao Ensino e a Pesquisa Científica e Tecnológica em Engenharias (Pró-Engenharias) e o Plano Sinos, que tem por objetivo estruturar o Plano de Bacia para o Rio dos Sinos. A importância deste trabalho vai de encontro com a necessidade de se desenvolverem alternativas que busquem melhorar a qualidade das águas residuárias lançadas na Bacia Hidrográfica do Rio dos Sinos. / his work was based on the monitoring of a system formed by three multi-stage Submerse Aerated Biofilters (BAS), applied to the post-treatment of effluent of the anaerobic reactor fed with mixture of landfill leachate and domestic sewage, being tested three different support media: lids and necks of PET bottles, broken stone nº4 and Pall rings, being denominated BAS 1, 2 and 3. The BAS are reactors with fixed biomass, in a way that the microorganisms adhere to the support media forming biofilm. In this way, this work had as objective to verify the occurrence of nitrifying microbiota in the set-off period of the system, established in 90 days. The presence of nitrifying bacteria was evaluated through polymerase chain reaction techniques (PCR) and technique of the most probable (NMP), seeking the quantifying of the microorganisms, specifically Nitrosomonas and Nitrobacter. The presence of these was confirmed by the results of the physical-chemical analysis and by the NMP technique. The counting of the bacteria of the Nitrosomonas gender for the 3 BAS presented a similar profile with values between 7,8 x 101 and >1,6 x 105(BAS1); 7,8 x 101 and 1,6 x 105(BAS2) and 2,4 x 101 and 9,2 x 104(BAS3). The same behavior was observed for bacteria of the Nitrobacter gender, which values vary between: < 1,8 x 101 and 1,6 x 104(BAS1); 1,8 x 101 and 2,4 x 103(BAS2); 1,7 x 101 and 3,5 x 103 (BAS3). The counting of bacteria of the Nitrobacter gender presented themselves lower in all the reactors. The levels of nitrate evaluated in the effluent showed the occurrence of an increase in the concentration during the monitored period in all the reactors presenting the following values: 74 to 922 mg/L (BAS 1), 95 to 910mg/L (BAS 2) and 33 to 910 mg/L (BAS 3), which can be related to the increase of the presence of nitrifying bacteria, according to the results of the NMP. The analysis of PCR, however, was harmed possibly by the presence of hindering substances making the amplification difficult. In this stage all the easily biodegradable organic matter had already been consumed by the anaerobic pre-treatment previously to the BAS, remaining in the affluent to the BAS only recalcitrant organic matter, which hindered the development of an adequate biofilm and possibly the amplification of the DNA of the nitrifying bacteria present in the system. This research is part of two more ample projects, the Teaching Aid Program and the Scientific and Technological Research in Engineering (Pro-Engineering) and the Sinos Plan, which has as objective to structure the Basin Plan for the Sinos River. The importance of this work meets the necessity of developing alternatives which seek to improve the quality of the wastewater thrown in the Hydrographic Basin of the Sinos River.

Climate change affects lake ecosystems in many ways by direct and indirect temperature impacts on hydrophysical structure, hydrology, chemical cycles and on biological interactions. The identification of these climate signals can be complicated and superimposed by other environmental changes, such as land use changes. The aim of this thesis was to seperate temperature effects from effects of management and other environmental influences and to understand the underlying complex processes causing significant changes of ecosystem states. This understanding is important for decisions of lake and reservoir managers to counteract unfavorable consequences of climate change. For the recent study, long-term data of meteorological, hydrophysical and biological variables (phytoplankton, crustacean zooplankton, fish) of the German drinking water reservoir Saidenbach were analysed. Based on this long-term data set, strong indicators for climate induced changes have been identified. In particular, increasing water temperatures since 1975, earlier break up of ice covers and an altered hydrophysical structure could be detected. Thereby, stratification stability increased and turbulent mixing decreased in summer. The water of the reservoir warmed more than the tributaries resulting in a trend to deeper entrainment of the inflows. As further indicators of climate change, an increased annual biomass of phytoplankton and species shifts in the phytoplankton community in spring and summer had been observed. During the spring mass development, the diatom Aulacoseira subarctica became dominant in recent years with warm winters and early ice-out. Its unusual spatial pattern with occurrences in aphotic depths could be explained by easier resuspension compared to other diatoms. By being resuspended first and establishing a high inoculum, A. subarctica profits from an earlier ice-out and earlier full circulation. In spite of a reduced nutrient loading to the epilimnion, in summer, the diatom Fragilaria crotonensis was displaced increasingly by cyanobacteria. This species shift could be explained well by the hydrophysical regime shift. Although, the annual total phytoplankton biomass increased since 1990, the crustacean zooplankton in Saidenbach reservoir did not seem to profit from improved food resources. To the contrary, Daphnia abundances reduced tremendously. We could show that the influcence of fish stocks were underestimated. The stocked silvercarp may have contributed up to 70 % of the total zooplanktivorous fish biomass which had a temperature and density dependent effect. The faster growth of Daphnia at higher temperatures could not compensate for the more actively grazing fish when stock of zooplankitvorous fish was too high. Still, temperature was identified as the most important factor that explained 29 % of the zooplankton phenology, while the second most important predictors were zooplanktivorous fish biomass and nutrient loading, explaining 18 % of the variance. The importance of submerged macrophytes in shallow lakes is well investigated. To increase also the understanding of their impact and their role during climate change on water quality in deep lakes, a model for stratified lakes that includes submerged macrophytes was developed. The simulations showed that macrophyte effects were mainly positive for water quality and macrophytes in deep lakes were able to potentially reduce summer phytoplankton, especially cyanobacteria by 50 % in 11 m deep and still by 15 % in 100 m deep oligotrophic lakes. Nutrient competition with phytoplankton contributed most to this macrophyte effect. In conclusion, for deep lake restoration the re-establishment of submerged macrophytes might be as important as for shallow lakes. The full lake model includes hydrophysical and ecological submodules and thus will allow further comprehensive climate simulations and the evaluation of the effectivity of adaptive strategies and scenarios for deep lakes and reservoirs. / Der Klimawandel beeinflusst Seeökosysteme vielfältig durch direkte und indirekte Temperatureffekte auf die hydrophysikalische Struktur, die Hydrologie, chemische Kreisläufe und biologische Interaktionen. Die Identifikation von Klimasignalen kann durch Landnutzungs- und weitere Umweltveränderungen überlagert werden. Ziel dieser Arbeit war es, Temperatureffekte von Effekten zu unterscheiden, die durch Gewässermanagement oder anderen Umweltveränderungen verursacht werden. Weiterhin sollten komplexe Prozesse verstanden werden, die zu signifikanten Veränderungen in Seeökosystemen führen. Dieses Verständnis ist für Talsperren- und Gewässermanager von besonderer Bedeutung, um ungewünschten Folgen des Klimawandels entgegenwirken zu können. Für die Studie wurden Langzeitdaten für meteorologische, hydrophysikalische und biologische Variablen (Phytoplankton, Crustaceen-Zooplankton, Fischbesatz) der Talsperre Saidenbach ausgewertet. Mehrere Indikatoren für die Auswirkungen des Klimawandels konnten basierend auf diesen Daten identifiziert werden. Diese gehören insbesondere eine Erhöhung der Wassertemperatur seit 1975, zeitigere Eisaufbrüche und eine veränderte Schichtungsstruktur. Dabei wurde im Sommer die Schichtungsstabilität höher und die Intensität der Durchmischung geringer. Das Wasser in der Talsperre erwärmte sich stärker als die Zuflüsse, wodurch diese sich zunehmend tiefer und unterhalb der Thermokline einschichten. Eine zunehmende jährliche Phytoplanktonbiomasse und Artenwechsel innerhalb der Planktongemeinschaft sind weitere Indikatoren für Klimafolgen. Die Kieselalge Aulacoseira subarctica erlangte in Jahren mit warmen Wintern und zeitigen Eisaufbrüchen eine Dominanz während der Frühjahrsentwicklung. Das ungewöhnliche Auftreten dieser Art in aphotischen Tiefen konnte durch eine leichtere Resuspension im Vergleich zu anderen Kieselalgen erklärt werden. Durch zeitige Resuspension gleich nach Eisaufbruch kann A. subarctica ein hohes Inokulum etablieren. Trotz reduzierter Nährstoffzufuhr ins Epilimnion wurde im Sommer die Kieselalge Fragilaria crotonensis vermehrt durch Cyanobakterien verdrängt, was jedoch gut mit den Änderungen der hydrophysikalischen Struktur erklärt werden kann. Obwohl seit 1990 insgesamt mehr Phytoplankton zur Verfügung steht konnte das Crustaceen- Zooplankton in der Talsperre Saidenbach nicht von diesen verbesserten Nahrungsbedingungen profitieren. Die Daphnia-Abundanzen waren seit 1990 stark verringert. Es konnte gezeigt werden, dass der Einfluss des Fischbesatzes unterschätzt wurde und die künstlich ins System eingebrachten Silberkarpfen zeitweise bis zu 70% der zooplanktivoren Fischbiomasse ausgemacht haben. Zoo- planktivore Fische haben einen temperatur- und dichteabhängigen Effekt auf das Zooplankton. Das schnellere Populationswachstum von Daphnia kann bei hohem Besatz mit zooplanktivoren Fischen nicht die erhöhte Fraßaktivität der Fische ausgleichen. Dennoch konnte Temperatur als der wichtigste Einflussfaktor auf die Phänologie des Zooplanktons identifiziert werden, gefolgt von zooplanktivorem Fisch und Nährstoffzufuhr. Die Wichtigkeit von submersen Makrophyten in Flachseen ist gut untersucht. Um den Einfluss von Makropyhten auf die Wasserqualität während des Klimawandels auch in tiefen Seen abschätzen zu können, wurde ein komplexes Seemodell entwickelt. Die Simulationen zeigen, dass sich Makrophyten hauptsächlich positiv auf die Wassergüte auswirken und zur Reduktion von Phytoplankton, insbesondere von Cyanobakterien im Sommer, beitragen. In einem 11 m tiefen See betrug die Reduktion 50 %, in 100 m tiefen oligotrophen Seen immer noch 15 %. Die Konkurrenz um Nährstoffe mit dem Phytoplankton war dabei die ursächliche Makrophyten-Plankton-Interaktion. Submerse Makrophyten könnten für die Restaurierung von tiefen Seen folglich genauso wichtig sein, wie für Flachseen. Das komplette Seemodell enthält hydrophysikalische und ökologische Module und ermöglicht damit weitere umfassende Simulationen zur Untersuchung der Auswirkungen des Klimawandels und zur Evaluation von Adaptionsstrategien für Seen und Talsperren.

Climate change affects lake ecosystems in many ways by direct and indirect temperature impacts on hydrophysical structure, hydrology, chemical cycles and on biological interactions. The identification of these climate signals can be complicated and superimposed by other environmental changes, such as land use changes. The aim of this thesis was to seperate temperature effects from effects of management and other environmental influences and to understand the underlying complex processes causing significant changes of ecosystem states. This understanding is important for decisions of lake and reservoir managers to counteract unfavorable consequences of climate change. For the recent study, long-term data of meteorological, hydrophysical and biological variables (phytoplankton, crustacean zooplankton, fish) of the German drinking water reservoir Saidenbach were analysed. Based on this long-term data set, strong indicators for climate induced changes have been identified. In particular, increasing water temperatures since 1975, earlier break up of ice covers and an altered hydrophysical structure could be detected. Thereby, stratification stability increased and turbulent mixing decreased in summer. The water of the reservoir warmed more than the tributaries resulting in a trend to deeper entrainment of the inflows. As further indicators of climate change, an increased annual biomass of phytoplankton and species shifts in the phytoplankton community in spring and summer had been observed. During the spring mass development, the diatom Aulacoseira subarctica became dominant in recent years with warm winters and early ice-out. Its unusual spatial pattern with occurrences in aphotic depths could be explained by easier resuspension compared to other diatoms. By being resuspended first and establishing a high inoculum, A. subarctica profits from an earlier ice-out and earlier full circulation. In spite of a reduced nutrient loading to the epilimnion, in summer, the diatom Fragilaria crotonensis was displaced increasingly by cyanobacteria. This species shift could be explained well by the hydrophysical regime shift. Although, the annual total phytoplankton biomass increased since 1990, the crustacean zooplankton in Saidenbach reservoir did not seem to profit from improved food resources. To the contrary, Daphnia abundances reduced tremendously. We could show that the influcence of fish stocks were underestimated. The stocked silvercarp may have contributed up to 70 % of the total zooplanktivorous fish biomass which had a temperature and density dependent effect. The faster growth of Daphnia at higher temperatures could not compensate for the more actively grazing fish when stock of zooplankitvorous fish was too high. Still, temperature was identified as the most important factor that explained 29 % of the zooplankton phenology, while the second most important predictors were zooplanktivorous fish biomass and nutrient loading, explaining 18 % of the variance. The importance of submerged macrophytes in shallow lakes is well investigated. To increase also the understanding of their impact and their role during climate change on water quality in deep lakes, a model for stratified lakes that includes submerged macrophytes was developed. The simulations showed that macrophyte effects were mainly positive for water quality and macrophytes in deep lakes were able to potentially reduce summer phytoplankton, especially cyanobacteria by 50 % in 11 m deep and still by 15 % in 100 m deep oligotrophic lakes. Nutrient competition with phytoplankton contributed most to this macrophyte effect. In conclusion, for deep lake restoration the re-establishment of submerged macrophytes might be as important as for shallow lakes. The full lake model includes hydrophysical and ecological submodules and thus will allow further comprehensive climate simulations and the evaluation of the effectivity of adaptive strategies and scenarios for deep lakes and reservoirs. / Der Klimawandel beeinflusst Seeökosysteme vielfältig durch direkte und indirekte Temperatureffekte auf die hydrophysikalische Struktur, die Hydrologie, chemische Kreisläufe und biologische Interaktionen. Die Identifikation von Klimasignalen kann durch Landnutzungs- und weitere Umweltveränderungen überlagert werden. Ziel dieser Arbeit war es, Temperatureffekte von Effekten zu unterscheiden, die durch Gewässermanagement oder anderen Umweltveränderungen verursacht werden. Weiterhin sollten komplexe Prozesse verstanden werden, die zu signifikanten Veränderungen in Seeökosystemen führen. Dieses Verständnis ist für Talsperren- und Gewässermanager von besonderer Bedeutung, um ungewünschten Folgen des Klimawandels entgegenwirken zu können. Für die Studie wurden Langzeitdaten für meteorologische, hydrophysikalische und biologische Variablen (Phytoplankton, Crustaceen-Zooplankton, Fischbesatz) der Talsperre Saidenbach ausgewertet. Mehrere Indikatoren für die Auswirkungen des Klimawandels konnten basierend auf diesen Daten identifiziert werden. Diese gehören insbesondere eine Erhöhung der Wassertemperatur seit 1975, zeitigere Eisaufbrüche und eine veränderte Schichtungsstruktur. Dabei wurde im Sommer die Schichtungsstabilität höher und die Intensität der Durchmischung geringer. Das Wasser in der Talsperre erwärmte sich stärker als die Zuflüsse, wodurch diese sich zunehmend tiefer und unterhalb der Thermokline einschichten. Eine zunehmende jährliche Phytoplanktonbiomasse und Artenwechsel innerhalb der Planktongemeinschaft sind weitere Indikatoren für Klimafolgen. Die Kieselalge Aulacoseira subarctica erlangte in Jahren mit warmen Wintern und zeitigen Eisaufbrüchen eine Dominanz während der Frühjahrsentwicklung. Das ungewöhnliche Auftreten dieser Art in aphotischen Tiefen konnte durch eine leichtere Resuspension im Vergleich zu anderen Kieselalgen erklärt werden. Durch zeitige Resuspension gleich nach Eisaufbruch kann A. subarctica ein hohes Inokulum etablieren. Trotz reduzierter Nährstoffzufuhr ins Epilimnion wurde im Sommer die Kieselalge Fragilaria crotonensis vermehrt durch Cyanobakterien verdrängt, was jedoch gut mit den Änderungen der hydrophysikalischen Struktur erklärt werden kann. Obwohl seit 1990 insgesamt mehr Phytoplankton zur Verfügung steht konnte das Crustaceen- Zooplankton in der Talsperre Saidenbach nicht von diesen verbesserten Nahrungsbedingungen profitieren. Die Daphnia-Abundanzen waren seit 1990 stark verringert. Es konnte gezeigt werden, dass der Einfluss des Fischbesatzes unterschätzt wurde und die künstlich ins System eingebrachten Silberkarpfen zeitweise bis zu 70% der zooplanktivoren Fischbiomasse ausgemacht haben. Zoo- planktivore Fische haben einen temperatur- und dichteabhängigen Effekt auf das Zooplankton. Das schnellere Populationswachstum von Daphnia kann bei hohem Besatz mit zooplanktivoren Fischen nicht die erhöhte Fraßaktivität der Fische ausgleichen. Dennoch konnte Temperatur als der wichtigste Einflussfaktor auf die Phänologie des Zooplanktons identifiziert werden, gefolgt von zooplanktivorem Fisch und Nährstoffzufuhr. Die Wichtigkeit von submersen Makrophyten in Flachseen ist gut untersucht. Um den Einfluss von Makropyhten auf die Wasserqualität während des Klimawandels auch in tiefen Seen abschätzen zu können, wurde ein komplexes Seemodell entwickelt. Die Simulationen zeigen, dass sich Makrophyten hauptsächlich positiv auf die Wassergüte auswirken und zur Reduktion von Phytoplankton, insbesondere von Cyanobakterien im Sommer, beitragen. In einem 11 m tiefen See betrug die Reduktion 50 %, in 100 m tiefen oligotrophen Seen immer noch 15 %. Die Konkurrenz um Nährstoffe mit dem Phytoplankton war dabei die ursächliche Makrophyten-Plankton-Interaktion. Submerse Makrophyten könnten für die Restaurierung von tiefen Seen folglich genauso wichtig sein, wie für Flachseen. Das komplette Seemodell enthält hydrophysikalische und ökologische Module und ermöglicht damit weitere umfassende Simulationen zur Untersuchung der Auswirkungen des Klimawandels und zur Evaluation von Adaptionsstrategien für Seen und Talsperren.