Summary Here we investigated whether there is evidence of local adaptation in strains of an ancestrally marine dinoflagellate to the lacustrine environment they now inhabit (optimal genotypes) and/or if they have evolved phenotypic plasticity (a range of phenotypes). Eleven strains of P olarella glacialis were isolated and cultured from three different environments: the polar seas, a hyposaline and a hypersaline Antarctic lake...

A fundamental question in ecology is whether microorganisms follow the same patterns as multicellular organisms when it comes to population structure and levels of genetic diversity. Enormous population sizes, predominately asexual reproduction and presumably high dispersal because of small body size could have profound implications on their genetic diversity and population structure. Here, we have analysed the population gene...

Increases in the long‐range aerial transport of reactive N species from low to high latitudes will lead to increased accumulation in the Arctic snowpack, followed by release during the early summer thaw. We followed the release of simulated snowpack N, and its subsequent fate over three growing seasons, on two contrasting high Arctic tundra types on Spitsbergen (79°N). Applications of 15 N (99 atom%) at 0.1 and 0.5 g N m −2 we...

A large mixotrophic ciliate (∼200 µm long) of the genus Stentor is a common constituent of the protozooplankton of Australian lakes. We investigated the photosynthetic rates of populations of this ciliate from two lakes, one in the Australian Capital Territory and the other on the New South Wales/Victorian border, in relation to photosynthesis by the whole phytoplankton community. The concentration of the ciliate varied betwee...