Changes in the genetic biodiversity of algae and cyanobacteria in terrestrial surface environments of forests and grasslands under the influences of land use and vegetation (SoilAlgae)

藻类和蓝藻是土壤微生物群落的重要组成部分。由于它们的光合自养生活方式，它们为土壤提供能量，碳和氧输入。在土壤中，它们与其他非光养原生生物和细菌连接成可变群落结构的功能组合。藻类和蓝藻对土壤生境有许多有益的影响，因为它们的色素，光合储存产品，细胞壁和粘液，脂肪酸和其他生物活性化合物的广泛的生物化学多样性。然而，藻类和蓝藻的生物多样性的复杂的土壤过程的实际相关性一直被低估，到目前为止，这可能是由于其分类和遗传生物多样性的认识不足。因此，我们将评估藻类和蓝藻在表层土壤中的物种和基因型分辨率的生物多样性的综合测试土地利用和植被的影响，在表土和相关的陆地表面环境中的光合自养微生物群落的遗传多样性。这将有助于更好地了解现实世界景观中生物多样性的驱动因素。因此，我们的目标是测试是否在地块之间的藻类/蓝藻多样性的变化（已经在我们的试点研究中观察到）可以与DFG SPP 1374的生物多样性勘探所提供的土地利用梯度。为了检验我们的工作假设，在所有高研究强度（VIP）的研究地块和与所有三个生物多样性探索站的森林和草原联合多地点实验相关的地块中进行了广泛的采样。从我们的试点研究的第一个提示，需要进一步测试更广泛的采样：光合自养微生物多样性的枯枝可能等于表层土壤，它连接枯枝和树皮。因此，枯枝富集（FOX实验）也可能意味着表土藻类/蓝藻多样性的富集。我们将研究蓝藻/蓝藻生物多样性对森林树冠开放（FOX实验）、土壤表面扰动（例如，通过松土和放牧）和施肥（FOX和LUX实验）。我们将测试草地表层土壤中的藻类/蓝藻生物多样性是否超过森林表层环境。基于扩增子的元条形码将被采用。用于评估藻类/蓝藻的多样性。23 S UPA标记用于所有真核生物藻类谱系和蓝细菌，并且优先扩增绿色藻类的ITS 2。我们的初步研究结果表明，森林中的藻类生物多样性的很大一部分可能代表仍然未知的物种或未研究的微藻谱系。为了解决它们的系统发育关系，我们寻求详细的系统发育分析，从叶绿体和核标记的长读扩增子。

Algae (photoautotrophic protists) and cyanobacteria are important components of microbial communities in soil. Due to their photoautotrophic lifestyle, they provide energy, carbon, and oxygen input to soils. In the soil, they are connected to other non-phototroph protists and bacteria to functional assemblages of changeable community structure. Algae and cyanobacteria have numerous beneficial effects on soil habitats due to their broad biochemical diversity of pigments, photosynthetic storage products, cell walls and mucilage, fatty acids, and other bioactive compounds. However, the actual relevance of the biodiversity of algae and cyanobacteria for the complex soil processes has been underestimated so far, which likely is due to an insufficient understanding of their taxonomic and genetic biodiversity. Therefore, we will assess the biodiversity of algae and cyanobacteria in surface soils at species and genotypic resolution by a comprehensive testing for land-use and vegetation influences on the genetic biodiversity of photoautotroph microbial communities in topsoils and related terrestrial surface environments. It will lead to a better understanding of the drivers of their biodiversity in real-world landscapes. Therefore, our goal is to test whether the variation in the algal/cyanobacterial diversity between plots (already observed in our pilot study) can be related to the land-use gradients provided by the Biodiversity Exploratories of the DFG SPP 1374. To test our working hypotheses serves a broad sampling in all research plots of high research intensity (VIP) and those plots associated to the joint multiple-sites experiments in forests and grasslands of all three Biodiversity Exploratories. First hints from our pilot study need to be further tested with a broader sampling: photoautotroph microbial diversity of deadwood may equal that of surface soil; it connects deadwood and bark. Therefore, deadwood enrichment (FOX experiment) could means also an enrichment of topsoil algae/cyanobacteria diversity. We will study the responses of the alga/cyanobacterial biodiversity to the opening of the forest canopy (FOX experiment), soil surface disturbances (e.g., by scarifying and grazing) and fertilization (FOX and LUX experiments). We will test whether the algal/cyanobacterial biodiversity in surface soil in grasslands exceeds that of surface environments of forests. Amplicon-based metabarcoding will be employed.for assessing the algal/cyanobacterial diversity. The 23S UPA marker serves for all eukaryote algal lineages and cyanobacteria and preferentially amplified ITS2 for green algae. Our preliminary results indicate that a large portion of the algal biodiversity in forests may represent still unknown species or unstudied lineages of microalgae. To resolve their phylogenetic relationships, we seek for detailed phylogenetic analyses from long-read amplicons of chloroplast and nuclear markers.