They are places where very strong conditions for the growing of plants. Habitats which must fight extreme conditions such as sunstrokes, droughts and high salinity with a very poor substrate especially in nutrients. Due to the wind they suffer constant movements and changes.
Here, the species require a high specialization. Plants are distributed in stripes depending on the distance from the sea. Dune systems such as Rodas, Muxieiro-Figueiras and San Martiño have so much botanic importance. They are sandy areas moved from the sea to the land by the wind. They are moved from the high part of the beach to the inland. If there are any obstacles like vegetation or rocks the wind is slower and lets the sand fall.
