Fritz 9707689 Diatom species distributions are highly correlated with ionic concentration (salinity) and lakewater anion composition, and it is these correlations that form the foundation for the use of diatoms as tools for climate reconstruction. However, the actual mechanisms behind these associations are unknown. Salinity may influences diatom physiology directly, by exerting an osmotic stress, or salinity may interact with other factors and thus indirectly affect species composition. Nutrient concentration and ratios frequently control primary production and algal community structure in lacustrine systems, and in saline lakes salinity and anion composition may influence nutrient availability to primary producers, as well as nutrient requirements and uptake by diatoms. Thus here we propose a series of laboratory experiments to test the effect of salinity and anion composition on the outcome of nutrient competition between diatoms.
