Microalgal biovolume is commonly calculated to assess the relative abundance (as biomass or carbon) of co-occurring algae varying in shape and/or size. However, a standardized set of equations for biovolume calculations from microscopically measured linear dimensions that includes the entire range of microalgal shapes is not available yet. In comparison with automated methods, the use of microscopical measurements allows high taxonomic resolution, up to the species level, and has fewer sources of error. We present a set of geometric shapes and mathematical equations for calculating biovolumes of >850 pelagic and benthic marine and freshwater microalgal genera. The equations are designed to minimize the effort of microscopic measurement. The similarities and differences between our proposal for standardization and previously published proposals are discussed and recommendations for quality standards given.

Biovolume calculation for pelagic and benthic microalgae

The rise of harmful cyanobacteria blooms: The potential roles of eutrophication and climate change

Algae have adopted two primary strategies to maximize the performance of Rubisco in photosynthetic CO2 fixation. This has included either the development of a CO2-concentrating mechanism (CCM), bas...

The diversity and coevolution of rubisco, plastids, pyrenoids, and chloroplast-based co2-concentrating mechanisms in algae

Non-pollen palynomorphs (NPP) in pollen slides form a large, inhomogeneous group of remains of organisms that represents a memory of former, often strictly local environmental conditions. A systematic approach of NPP documentation led to a strong development of the field in the last 40 years, and the total amount of NPP exceeds 1300. A large number of NPP remains unknown and identified NPP belong to a wide variety of taxonomic groups such as Ascomycetes, Basidiomycetes, Hyphomycetes, Zygomycetes, Cyanobacteria, green algae, cysts of dinoflagellates, roundworms, flatworms, testate amoebae, rotifers, and tardigrades. We give an overview, illustrate and discuss the palaeoenvironmental indicator value of a selection of NPP important for environmental reconstructions at, or close to, archaeological sites in connection with human impact.

Non-Pollen Palynomorphs

Tropical rainfall patterns control the subsistence lifestyle of more than one billion people. Seasonal changes in these rainfall patterns are associated with changes in the position of the intertropical convergence zone, which is characterized by deep convection causing heavy rainfall near 10 ! N in boreal summer and 3 ! N in boreal winter. Dynamic controls on the position of the intertropical convergence zone are debated, but palaeoclimatic evidence from continental Asia, Africa and the Americas suggests that it has shifted substantially during the past millennium, reaching its southernmost position some time during the Little Ice Age (AD1400‐1850). However, without records from the meteorological core of the intertropical convergence zone in the Pacific Ocean, quantitative constraints on its position are lacking. Here we report microbiological, molecular and hydrogen isotopic evidence from lake sediments in the Northern Line Islands, Galapagos and Palau indicating that the Pacific intertropical convergence zone was south of its modern position for most of the past millennium, by as much as 500km during the Little Ice Age. A colder Northern Hemisphere at that time, possibly resulting from lower solar irradiance, may have driven the intertropical convergence zone south. We conclude that small changes in Earth’s radiation budget may profoundly affect tropical rainfall.

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Hanuš Ettl

Papers

Süsswasserflora von Mitteleuropa

Centrales, fragilariaceae, eunotiaceae

Syllabus der Boden-, Luft- und Flechtenalgen

Achnanthaceae, kritische Ergänzungen zu Navicula (Lineolatae) und Gomphonema Gesamtliteraturverzeichnis

Chrysophyceae und Haptophyceae