Mechanisms underlying regime shifts to picophytoplankton dominance in coastal water bodies

人类种群向水生生态系统注入营养物质，导致了新的人类驱动的浮游植物群落组合，在某些情况下，以小细胞为主。由于新建立的浮游植物群落的弹性，管理努力往往无法恢复这样的系统。我推测，小型浮游植物不仅将主宰它们目前预期的超寡营养生态位，还将主宰一些新出现的富营养化系统，对食物链和生态系统功能产生影响。重点放在异氰酸杆菌上。它有专门适应沿海水域的光系统，一些系统已经描述了全年的优势。特别是近海水域，环境因素呈现出非常动态的变化，我将采用多因素方法。其目的是分析与生态生理相关的环境变化对小型浮游植物生长和功能的影响，这些浮游植物是沿海新兴的优势物种。环境组合(光、温度、营养物质)最初将以高通量方法进行测试，该方法基于带有自动生长分析的平行井板。随后，将在较大的浊度计单元中研究关键的环境组合，以测试浮游植物对波动环境的生理反应。为了完成这些研究，我将测试新的混合型浊度计，以维持环境制度。然后，从浊度器流出的水将接种到下游无菌批次微培养物中，用于短期实验，以研究遗传蛋白遗产和来自不同初始驯化状态的细胞中的资源分配的影响。将多个相互作用的变量与重要但非模型物种纳入其中将是有风险的，但我们对系统的理解缺乏动态的超维方法。这一结果将有助于形成对人类世浮游植物群落演替的新的理论认识。

Human populations load aquatic ecosystems with nutrients, leading to new anthropogenically driven phytoplankton community assemblages, in some cases dominated by small cells. Management efforts often fail to restore such systems, due to resilience of the newly established phytoplankton communities. I hypothesize that small phytoplankton taxa are coming to dominate not only their expected current ultra-oligotrophic niches, but also some emerging eutrophied systems, with effects on food web and ecosystem functions. The focus is on the picocyanobacterium Cyanobium. It has photosystems specially adapted to coastal waters and a year-round dominance is already described for some systems. Since especially coastal waters show a very dynamic change of environmental factors, I will use multifactorial approaches. The aim is to analyse the effect of ecophysiologically relevant environmental changes on the growth and function of small phytoplankton species, which are emerging coastal dominants. Environmental combinations (light, temperature, nutrients) will be initially tested in a high-throughput approach based upon parallel well plates with automated growth analyses. Subsequently, key environmental combinations will be studied in larger turbidostat units to test physiomic responses of phytoplankton to fluctuating environments. To achieve these studies I will test new hybrid-turbidostats to maintain environmental regimes. Outflow from the turbidostats will then inoculate downstream sterile batch microcultures, for short term experiments on the effects of inherited protein legacies and resource allocations in cells coming from different initial acclimation states. The inclusion of multiple interacting variables with important, but non-model species, will be risky, but our system understanding lacks dynamic hyper-dimensional approaches. The results will help formulate a new theoretical understanding of phytoplankton community successions in the Anthropocene.