Where Land Meets Sea: Biology of Coastal Soils

The aim of the present review is to analyze functionally important plantmicrobe interactions in soil leading to establishment of characteristic vegetation patterns in coastal habitats with a special emphasis on sea wrack-dependent vegetation. Effect of fluctuating salinity on microbial diversity and activity is analyzed, further focusing on specific features of nitrogen cycle in coastal habitats. Two types of plant symbioses-with mycorrhizal fungi and nitrogen-fixing bacteria-are emphasized as being of special functional importance for coastal plants. As importance of sea wrack deposits for stimulation of microbial processes in coastal habitats is almost a completely neglected aspect of biology of coastal soils, an attempt is made to provide overview of general aspects of establishment of drift line vegetation, followed by outline of possible functionally important microbiological activities. It is concluded that, in order to get better insight in ecological mechanisms underlying vegetation establishment and maintenance in coastal habitats affected by wrack deposition, assessment of microbiological processes is of critical importance both at the level of functional activity and taxonomical diversity.