Consideraciones sobre la comunidad de diatomeas en relación a gradientes de altitud y salinidad en humedales de la Puna y los Altos Andes (Catamarca y Jujuy, Argentina)

Background and Aims: In the Puna and Prepuna Argentina there is an important number of high altitude wetlands from purely sweet to frankly hyperhaline. This contribution aimed to integrate the information collected in eight years of study (1998 and 2005) and analyze the distribution of taxa along gradients of height (2600-4700 m asl) and salinity (0.2-104 g L -1 ). M&M: We analyzed the diatoms found in our previous surveys of 57 wetlands located in the provinces of Catamarca and Jujuy between 2340 and 4683 m asl. Results: We identified 73 genera of diatoms with 375 infrageneric taxa and many of them recorded for the first time in the country (29) or in the region of our study (331). The best genera represented in terms of number of species were Nitzschia (43), Navicula (37), Pinnularia (21), Surirella (17), Planothidium (15), Halamphora (13) Craticula (12), 2 Amphora and Stauroneis 10). In the oligohaline wetlands, specific richness fluctuated between 7 and 69, mesohaline between 18 and 54 and polyhaline between 29 and 49. Regarding the height, between 4,301-4,500 m asl, there was a significant decrease in the number of species. Conclusions: The specific richness does not seem to have a direct relation with the altitude and salinity, reason why we postulate that other factors have influence on the diversity in the environments of high altitude analyzed. In this contribution, we report new ranges of tolerance to salinity and height for many taxa.