XVI International Botanical Congess

The coastal plain of Peruvian land has peculiar wetland ecosystems with lagoons which appear as oasis in the vast desert. The evaluated superficial lagoons located between 8? 52 to 11? 10' LS and 77? 30' to 78? 37' LO are surrounded by the lomas, initial slopes of the Occidental side of The Andes, and from north to south are: Guadalupito, Las Salinas, Chimus and Huacho. Standard algal collection as well as the surrounded higher terrestrial vegetation were carried out irregularly between 1985-1996. The aquatic salinity gradients were between 35-320 o/oo (NaC1). Comparisons between community diversity (benthic epizoic, endolithic, epiphytic, plancktic) of the coastal lagoons let us establish indicators species for these extreme ecosystems such as the nitrogen fixers Nodularia harveyana and Calothrix crustacea. The higher halophytes Batis maritima (Batidaceae) and Salicornia fruticosa (Chenopodiaceae) are substrates for the stratified epiphytic algal communities such as the poikilohydrics Trentepohlia sp. and Pleurocapsa. entophysaloides. Interactions of submerged communities of A. halophytica with halophile bacteria and the brine shrimp Artemia is recognized.