Langzeit Adaptation der Coccolithophoride Emiliania huxleyi an Ozean Versauerung und globale Erwärmung

This Thesis summarizes the adaptive effects of ocean acidification and global warm on the coccolithophore Emiliania huxleyi. The adaptive effects were experimentally assessed in a long term evolutionary experiment. After 2100 asexual generations of selection to CO2 the fitness (growth rate) increased slightly over time under 1100 µatm pCO2. Under 2200 µatm pCO2 the fitness advantage of 5% at 500 generations remained unchanged. The phenotypic trait of calcification was partly restored within 500 generations. Thereafter, calcification was reduced in response to selection. The reduction of calcification was not constitutively, as the calcite per cell quotas were restored when assessed with 400 µatm pCO2. Temperature adaptation occurred independently of ocean acidification levels. The fitness increase in growth rate due was up to 16% in populations adapted to high temperature and high CO2 compared to not adapted cells under selection conditions. The ratio of particular inorganic (PIC) and organic carbon (PIC:POC) recovered to their initial ratio after temperature adaptation, even under elevated CO2. Cells evolved to a smaller size accompanied by a reduction in POC-content. Production rates were restored to values under present-day ocean conditions, owing to adaptive evolution in growth rate. Temperature adaptation increased the effect on persisting CO2 adaptation in growth rate. The immediate physiological effect on PIC per cell was diminished compared to the lower temperature treatment, and so were the adaptive effects. Temperature adaptation reduced the negative effects of ocean acidification. Both adaptations were necessary to receive the full fitness effect under high-temperature-high-CO2-conditions. As consequence both adaptive effects are additive. Global warming may reduce the adverse effects of ocean acidification on E. huxleyi populations. My results show further, that marine phytoplankton may evolve changes in the plastic response under future ocean conditions

Long-term adaptation of the coccolithophore Emiliania huxleyi to ocean acidification and global warming

This Thesis summarizes the adaptive effects of ocean acidification and global warm on the coccolithophore Emiliania huxleyi. The adaptive effects were experimentally assessed in a long term evolutionary experiment. After 2100 asexual generations of selection to CO2 the fitness (growth rate) increased slightly over time under 1100 µatm pCO2. Under 2200 µatm pCO2 the fitness advantage of 5% at 500 generations remained unchanged. The phenotypic trait of calcification was partly restored within 500 generations. Thereafter, calcification was reduced in response to selection. The reduction of calcification was not constitutively, as the calcite per cell quotas were restored when assessed with 400 µatm pCO2. Temperature adaptation occurred independently of ocean acidification levels. The fitness increase in growth rate due was up to 16% in populations adapted to high temperature and high CO2 compared to not adapted cells under selection conditions. The ratio of particular inorganic (PIC) and organic carbon (PIC:POC) recovered to their initial ratio after temperature adaptation, even under elevated CO2. Cells evolved to a smaller size accompanied by a reduction in POC-content. Production rates were restored to values under present-day ocean conditions, owing to adaptive evolution in growth rate. Temperature adaptation increased the effect on persisting CO2 adaptation in growth rate. The immediate physiological effect on PIC per cell was diminished compared to the lower temperature treatment, and so were the adaptive effects. Temperature adaptation reduced the negative effects of ocean acidification. Both adaptations were necessary to receive the full fitness effect under high-temperature-high-CO2-conditions. As consequence both adaptive effects are additive. Global warming may reduce the adverse effects of ocean acidification on E. huxleyi populations. My results show further, that marine phytoplankton may evolve changes in the plastic response under future ocean conditions

Long-term dynamics of adaptive evolution in a globally important phytoplankton species to ocean acidification

Marine phytoplankton may adapt to ocean change, such as acidification or warming, because of their large population sizes and short generation times. Long-term adaptation to novel environments is a dynamic process, and phenotypic change can take place thousands of generations after exposure to novel conditions. We conducted a long-term evolution experiment (4 years = 2100 generations), starting with a single clone of the abundant and widespread coccolithophore Emiliania huxleyi exposed to three different CO2 levels simulating ocean acidification (OA). Growth rates as a proxy for Darwinian fitness increased only moderately under both levels of OA [+3.4% and +4.8%, respectively, at 1100 and 2200 μatm partial pressure of CO2 (Pco2)] relative to control treatments (ambient CO2, 400 μatm). Long-term adaptation to OA was complex, and initial phenotypic responses of ecologically important traits were later reverted. The biogeochemically important trait of calcification, in particular, that had initially been restored within the first year of evolution was later reduced to levels lower than the performance of nonadapted populations under OA. Calcification was not constitutively lost but returned to control treatment levels when high CO2–adapted isolates were transferred back to present-day control CO2 conditions. Selection under elevated CO2 exacerbated a general decrease of cell sizes under long-term laboratory evolution. Our results show that phytoplankton may evolve complex phenotypic plasticity that can affect biogeochemically important traits, such as calcification. Adaptive evolution may play out over longer time scales (>1 year) in an unforeseen way under future ocean conditions that cannot be predicted from initial adaptation responses

Development, status and objectives of the vegetation mapping in Germany

Die ersten Vegetationskartierungen in Deutschland erfolgten durch Hueck in den 1930er Jahren: 1936 in seiner „Pflanzengeographie Deutschlands“ mit neun Karten der natürlichen Vegetation der neun deutschen Teilregionen 1:1 300 000 und einer Übersicht 1:6 Mio., 1938 im Atlas für Mitteleuropa 1:3 Mio. - 1964 veröffentlichten SCAMONI und Mitarbeiter eine „Karte der natürlichen Vegetation der Deutschen Demokratischen Republik“ 1:500 000 mit Erläuterungsband. Eine überarbeitete Version 1:750 000 im „Atlas DDR“ lag dem Beitrag zur Europakarte zugrunde. - In Westdeutschland wurde die Kartierung der Potentiellen Natürlichen Vegetation von TÜXEN (1956) initiiert und von TRAUTMANN vorangebracht mit 4 großräumigen Teilkarten 1:200 000 und einer groben Übersichtskarte der Bundesrepublik Deutschland 1:1 Mio., deren feiner gegliederte Version als Beitrag für die Europakarte diente. Ferner sind eine Vielzahl von Regional- und Landeskarten entstanden. - Nach der Wiedervereinigung Deutschlands 1990 wurden nach der neuen Konzeption die Karten der Potentiellen Natürlichen Vegetation in den östlichen Bundesländern und nachfolgend in Süddeutschland neu bearbeitet. Inzwischen liegen alle fünf Übersichtskarten von Deutschland im Maßstab 1:500 000 vor und werden mit zwei Erläuterungsbänden für Nord- und Süddeutschland zum Druck vorbereitet.The first vegetation mapping in Germany was conducted by HUECK in the 1930s. His 1936 publication ‘Pflanzengeographie Deutschlands’ [Plant geography of Germany] contained nine maps of the natural vegetation of the nine German regions at the scale of 1: 1,300,000 and an overview map at the scale of 1: 6 million, while the 1938 work ‘Atlas für Mitteleuropa’ [Atlas for central Europe] contained maps at a scale of 1: 3 million. - SCAMONI and colleagues published a ‘Map of the natural vegetation of the GDR’ at a scale of 1: 500,000 and an explanatory text for the eastern part in 1964. A revised version at a scale of 1: 750,000 in the ‘Atlas DDR’ formed the basis for a contribution to the map of the natural vegetation of Europe. - In the Federal Republic of Germany the mapping of the potential natural vegetation was initiated by TÜXEN (1956) and continued by TRAUTMANN who created four partial maps of larger regions at a scale of 1: 200,000 and a first survey map of the Federal Republic of Germany at a scale of 1: 1 million as well as a more detailed version which has been integrated into the map of the natural vegetation of Europe. In additon, numerous regional maps of the German Bundesländer were created at that time. - Following German reunification in 1990, maps of the potential natural vegetation in the eastern Bundesländer and subsequently that of southern Germany have been revised. Meanwhile, the complete set of five German survey maps at a scale of 1: 500,000 has been finished. Presently, these maps are being prepared for print together with two explanatory texts for northern and southern Germany