Periodic flooding restrains local succession of microphytobenthos in floodplain lakes

Periodic flooding of river floodplains and connectivity of floodplain lakes and rivers is suggested to interfere with the succession of microphytobenthos. To analyse this we: 1. studied the impact of flooding on the relationship between irradiance level (depth) and microphytobenthic community composition; 2. sampled three lakes with different connection-disconnection patterns; and 3. studied seasonal variation in community composition in one floodplain lake subjected to several flooding events. Shortly after flooding and subsequent connection of floodplain lakes, microphytobenthic communities showed a uniform species composition. Disconnection of the lakes was followed by a succession of species according to local environmental conditions. However, assemblages were often set back before outgrowth of local species or divergence of community composition became prominent. It is therefore concluded that flooding and the associated connection-disconnection regime of floodplain waters overrule the selective effects of local environmental parameters.