A survey of the distribution and the periodicity of eight Vaucheria species ( V. arcassonensis. V. compacta, V. coronata. V. intermedia, V. minuta. V. sphaerospora. V. thuretii and V. vipera) on the Dutch salt marsh Springersgors in relation to environment and vegetation pattern of algae and higher plants is given. The quantitative changes occurring in the algal vegetation (green algae, blue-green algae and Vaucheria spp.) on two permanent quadrates, checked monthly algae and higher plants is given over a period of two years, are given in relation to some important ecological factors. Both sample plots, situated at MHWS level on the tidal marsh, constitute an instable habitat with large changes in soil moisture content (42-165 g H2O/100 g soil) and in salinity of the soil moisture (0.8-72.4°/oo Cl-). The periodicity of five Vaucheria species could be correlated with the action of extreme environmental conditions (desiccation, high salinities, frost).